Agronomy

17 pages, 4207 KiB

Open AccessFeature PaperEditor’s ChoiceArticle

Dynamics of Crop Evapotranspiration of Four Major Crops on a Large Commercial Farm: Case of the Navajo Agricultural Products Industry, New Mexico, USA

by Koffi Djaman, Komlan Koudahe and Ali T. Mohammed

Agronomy 2022, 12(11), 2629; https://doi.org/10.3390/agronomy12112629 - 26 Oct 2022

Cited by 1 | Viewed by 1832

Abstract

Crop evapotranspiration (ETa) is the main source of water loss in farms and watersheds, and with its effects felt at a regional scale, it calls for irrigation professionals and water resource managers to accurately assess water requirements to meet crop water use. On [...] Read more.

Crop evapotranspiration (ETa) is the main source of water loss in farms and watersheds, and with its effects felt at a regional scale, it calls for irrigation professionals and water resource managers to accurately assess water requirements to meet crop water use. On a multi-crop commercial farm, different factors affect cropland allocation, among which crop evapotranspiration is one of the most important factors regarding the seasonally or annually available water resources for irrigation in combination with the in-season effective precipitation. The objective of the present study was to estimate crop evapotranspiration for four major crops grown on the Navajo Agricultural Products Industry (NAPI) farm for the 2016–2010 period to help crop management in crop plant allocation based on the different objectives of the NAPI. The monthly and seasonal satellite-based ETa of maize, potatoes, dry beans, and alfalfa were retrieved and compared using the analysis of variance and the least significant difference (LSD) at 5% of significance. Our results showed the highly significant effects of year, months, and crops. The year 2020 obtained the highest crop ETa, and July had the most evapotranspiration demand, followed by August, June, September, and May, and the pool of April, March, February, January, December, and November registered the lowest crop ETa. Maize monthly ETa varied from 17.5 to 201.7 mm with an average seasonal ETa of 703.8 mm. The monthly ETa of potatoes varied from 9.8 to 207.5 mm, and their seasonal ETa averaged 600.9 mm. The dry bean monthly ETa varied from 10.4 to 178.4 mm, and the seasonal ETa averaged 506.2 mm. The alfalfa annual ETa was the highest at 1015.4 mm, as it is a perennial crop. The alfalfa monthly ETa varied from 8.2 to 202.1 mm. The highest monthly crop ETa was obtained in July for all four crops. The results of this study are very critical for cropland allocation and irrigation management under limited available water across a large commercial farm with multiple crops and objectives. Full article

(This article belongs to the Special Issue Precision Water Management)

► Show Figures

Figure 1

18 pages, 3501 KiB

Open AccessEditor’s ChoiceArticle

Weed Pressure, Nutrient Content, and Seed Yield in Field Grown Sulfonylurea-Resistant Camelina sativa and Brassica napus

by James V. Anderson, Brant B. Bigger, Kirk Howatt, Joseph Mettler and Marisol T. Berti

Agronomy 2022, 12(11), 2622; https://doi.org/10.3390/agronomy12112622 - 25 Oct 2022

Cited by 2 | Viewed by 1833

Abstract

Camelina [(Camelina sativa (L.) Crantz], an oilseed species of Brassicaceae, does not have approved herbicides for weed control, which limits its expansion as a commercial crop. To evaluate agronomic traits and ecosystem services of non-transgenic cultivars of sulfonylurea-resistant camelina and canola ( [...] Read more.

Camelina [(Camelina sativa (L.) Crantz], an oilseed species of Brassicaceae, does not have approved herbicides for weed control, which limits its expansion as a commercial crop. To evaluate agronomic traits and ecosystem services of non-transgenic cultivars of sulfonylurea-resistant camelina and canola (Brassica napus L.), a field study was conducted near Fargo, North Dakota. Two replicated locations (NDSU and NW22) were set up in a randomized complete block design including four blocks of camelina, canola, and fallow per location. Camelina and canola were seeded (18 May) at 4.9 and 2.9 kg ha⁻¹, respectively, using 19-cm row spacing. Data was collected mid- and late-season (29 June and 22 July 2020 respectively) for crop and weed stem count (no. m⁻²), biomass dry matter (kg m⁻²), and nutrient (N, P, K, S) content (kg ha⁻¹), as-well-as final season (7 August) seed yield (kg ha⁻¹) for camelina and canola treated with and without sulfonylurea. Using Prefer 90 (NIS) at 0.25% v/v, camelina was treated with thifensulfuron at 6.3 g a.i. ha⁻¹, and canola was treated with thifensulfuron at 10.5 g a.i. ha⁻¹ and tribenuron at 5.3 g a.i. ha⁻¹. Sulfonylurea-resistant camelina and canola reduced late-season dry weight biomass of weeds by >75% and ≥60%, respectively, compared with fallow plots. Application of sulfonylurea herbicides to camelina or canola prior to mid-season analyses was not a significant factor (p ≤ 0.05) for reducing weed pressure and generally had little impact on altering crop biomass, seed yield, and nutrient retention. However, in some cases, herbicide treatment had an additive effect of reducing weed pressure over that of camelina or canola alone. Depending on the rotational cropping system, sulfonylurea-resistant camelina and canola should provide additional options for integrated weed management approaches and reducing nutrient leaching in the upper Midwest and northern Great Plains of the USA. Full article

► Show Figures

Figure 1

13 pages, 5761 KiB

Open AccessEditor’s ChoiceArticle

Factors Driving Autumn Quercus Flowering in a Thermo-Mediterranean Area

by Herminia García-Mozo, Rocío López-Orozco, Jose Oteros and Carmen Galán

Agronomy 2022, 12(11), 2596; https://doi.org/10.3390/agronomy12112596 - 22 Oct 2022

Cited by 7 | Viewed by 1080

Abstract

The flowering period of plants is a critical time since it determines their reproductive success. Flowering is controlled by different factors including genetic regulation and environmental conditions. In the Mediterranean area, favourable conditions usually occur in spring, when most plant species flower including [...] Read more.

The flowering period of plants is a critical time since it determines their reproductive success. Flowering is controlled by different factors including genetic regulation and environmental conditions. In the Mediterranean area, favourable conditions usually occur in spring, when most plant species flower including those of the Mediterranean Quercus genus. This paper reveals and analyses an unusual and lesser-known phenomenon occurring in the two main Mediterranean agroforestry ecosystems of South Europe, the Mediterranean forest and “dehesa”, that is, a second flowering occurring in autumn for the species Quercus ilex subsp. ballota (holm oak). The continuous pollen monitoring of the atmosphere in the city of Cordoba (southern Spain) for 25 years, together with field phenological observations in the area, has indicated that, apart from the main pollination period in spring, secondary flowerings also occasionally occur in this area, specifically in autumn. The present work examines these uncommon pollination events detected in the autumns of certain years with the aim of determining the main environmental factors that influence and control them. During the 25-year study period, there were 7 years in which a secondary Quercus flowering was detected in the area from the second half of October until the end of November. The univariate statistical analysis of the influence of environmental variables determined that the meteorological conditions in September were the most influential. Low mean temperatures, together with record rainfall in that month, led to autumn flowering events. The phenological characteristics of the spring pollen season were also influential. In the years with a shorter spring, the Quercus pollen season tended to present autumn flowerings. A multivariate adaptive regression splines (MARS) model was built to explain the effects of the different variables on the occurrence of autumn pollination. The results indicated that the combined effect of three predicting variables, September rainfall, the length of the spring pollen season, and the end of the spring pollen season, explained 92% of the variance. The validation showed a strong relationship between the expected and the observed autumn pollen concentrations. Therefore, the present analysis of a long-term pollen database revealed that the main causes of this unusual second flowering in autumn were strongly related to climate change, i.e., strong dry summers and warm autumns. In addition, the results showed that the phenomenon was more frequent in the years with low pollination during spring due to different meteorological events potentiated by climate change, such as dryness or heavy rain episodes, as a way of ensuring acorn crops. The results explain how this unusual and lesser-known phenomenon in agroforestry dynamics is related to the adaptation to climate change and the main factors that are driving it, as well as the potential consequences for these important and endangered Mediterranean ecosystems. Full article

(This article belongs to the Special Issue Adaptations to Climate Change in Agricultural Systems)

► Show Figures

Figure 1

21 pages, 1278 KiB

Open AccessEditor’s ChoiceArticle

Effect of Different Cover Crops, Mass-Trapping Systems and Environmental Factors on Invertebrate Activity in Table Olive Orchards—Results from Field Experiments in Crete, Greece

by Nikolaos Volakakis, Emmanouil Kabourakis, Leonidas Rempelos, Apostolos Kiritsakis and Carlo Leifert

Agronomy 2022, 12(10), 2576; https://doi.org/10.3390/agronomy12102576 - 20 Oct 2022

Cited by 3 | Viewed by 1524

Abstract

Background: Although the negative effects of insecticides and herbicides on beneficial and non-target invertebrates are well documented, there is limited information on potential negative impacts of pest and weed management practices used in organic farming on invertebrate activity. Methods: Using established field experiments [...] Read more.

Background: Although the negative effects of insecticides and herbicides on beneficial and non-target invertebrates are well documented, there is limited information on potential negative impacts of pest and weed management practices used in organic farming on invertebrate activity. Methods: Using established field experiments designed to compare different ground cover crops (used to suppress weeds and increase nitrogen availability and soil health) and mass-trapping systems (used for olive fly control) in organic olive production systems, we monitored the impact of these practices on invertebrate activity. Results: When different ground cover crops were compared, ground cover crops established from a vetch/pea/barley seed mixtures resulted in significantly higher parasitic wasps activity than ground cover vegetation in control plots (plots in which Medicago seed were sown and failed to establish) that were dominated by the weed Oxalis pes-caprae. When two bottle based mass-trapping systems were compared, the traps caught similar numbers of olive flies and some non-target invertebrates (mainly other Diptera, Neuroptera and Lepidotera and Formicidae), although no parasitic wasps or pollinators (bees; bumble bees) were caught in traps. Analyses of invertebrate profiles found in McPhail monitoring traps showed that invertebrate activity profiles were similar in plots with and without mass-trapping devices. In addition, as expected, redundancy analyses showed that climatic parameters (temperature, rainfall, humidity, wind direction) are significant explanatory variables/drivers for invertebrate activity in olive orchards. Conclusions: The results presented indicate that mixed legume/cereal ground cover crops may increase the activity of parasitic wasps and may act as a reservoir for natural enemies of agricultural pest and that olive fly mass-trapping systems may lure and kill some non-target invertebrates, but do not affect the activity of two main groups of beneficial invertebrates namely pollinators and parasitic wasps. Full article

(This article belongs to the Special Issue Integrated Soil, Crop and Human Nutrition and Health Management in Organic Agriculture)

► Show Figures

Figure 1

20 pages, 1934 KiB

Open AccessEditor’s ChoiceArticle

Shade and Altitude Implications on the Physical and Chemical Attributes of Green Coffee Beans from Gorongosa Mountain, Mozambique

by Crimildo T. Cassamo, Adilson V. J. Mangueze, António E. Leitão, Isabel P. Pais, Rita Moreira, Claudine Campa, Rogério Chiulele, Fabrício O. Reis, Isabel Marques, Paula Scotti-Campos, Fernando C. Lidon, Fábio L. Partelli, Ana I. Ribeiro-Barros and José C. Ramalho

Agronomy 2022, 12(10), 2540; https://doi.org/10.3390/agronomy12102540 - 18 Oct 2022

Cited by 13 | Viewed by 3552

Abstract

Coffea arabica L. is as a tropical crop that can be grown under monocrop or agroforestry (AFS) systems, usually at altitudes greater than 600 m, with suitable environmental conditions to bean quality. This study aimed to assess the effect of altitude (650, 825, [...] Read more.

Coffea arabica L. is as a tropical crop that can be grown under monocrop or agroforestry (AFS) systems, usually at altitudes greater than 600 m, with suitable environmental conditions to bean quality. This study aimed to assess the effect of altitude (650, 825, and 935 m) and light conditions (deep shade—DS, and moderate shade—MS provided by native trees, and full Sun—FS) on the physical and chemical attributes of green coffee beans produced in the Gorongosa Mountain. Regardless of altitude, light conditions (mainly MS and FS) scarcely affected most of the studied physical and chemical attributes. Among the few exceptions in physical attributes, bean mass tended to lower values under FS in all three altitudes, whereas bean density increased under FS at 650 m. As regards the chemical compound contents, sporadic changes were found. The rises in trigonelline (MS and FS at 935 m), soluble sugars (FS at 935 m), and the decline in p-coumaric acid (MS and FS at 825 m), may indicate an improved sensory profile, but the rise in FQAs (FS at 825 m) could have a negative impact. These results highlight a relevant uncertainty of the quality changes of the obtained bean. Altitude (from 650 to 935 m) extended the fruit maturation period by four weeks, and altered a larger number of bean attributes. Among physical traits, the average sieve (consistent tendency), bean commercial homogeneity, mass, and density increased at 935 m, whereas the bean became less yellowish and brighter at 825 and 935 m (b*, C* colour attributes), pointing to good bean trade quality, usually as compared with beans from 650 m. Furthermore, at 935 m trigonelline and 5-CQA (MS and FS) increased, whereas FQAs and diCQAs isomers declined (in all light conditions). Altogether, these changes likely contributed to improve the sensory cup quality. Caffeine and p-coumaric acid showed mostly inconsistent variations. Overall, light conditions (FS, MS, or DS) did not greatly and consistently altered bean physical and chemical attributes, whereas altitude (likely associated with lower temperature, greater water availability (rainfall/fog), and extended maturation period) was a major driver for bean changes and improved quality. Full article

(This article belongs to the Special Issue Coffee—from Plant to Cup)

► Show Figures

Figure 1

40 pages, 4344 KiB

Open AccessEditor’s ChoiceReview

Ecosystem-Based Practices for Smallholders’ Adaptation to Climate Extremes: Evidence of Benefits and Knowledge Gaps in Latin America

by Raffaele Vignola, M. Jimena Esquivel, Celia Harvey, Bruno Rapidel, Pavel Bautista-Solis, Francisco Alpizar, Camila Donatti and Jacques Avelino

Agronomy 2022, 12(10), 2535; https://doi.org/10.3390/agronomy12102535 - 17 Oct 2022

Cited by 5 | Viewed by 4106

Abstract

Agricultural practices of smallholder farming systems of Latin America can play an important role in reducing their exposure to the risks associated with climate extremes. To date, however, there is no systematic analysis of scientific evidence for the extent to which these practices [...] Read more.

Agricultural practices of smallholder farming systems of Latin America can play an important role in reducing their exposure to the risks associated with climate extremes. To date, however, there is no systematic analysis of scientific evidence for the extent to which these practices can provide the multiple benefits needed for smallholders to adapt to climate extremes. In this paper, we searched scientific databases to review scientific evidence of the benefit provided by twenty-six practices in crops commonly farmed by smallholders in the region and highly relevant for their food and nutrition security; namely, coffee, maize and beans. We reviewed scientific documents (n = 304) published in the period 1953–2021 to register evidence of the practices’ effects on fifty-five benefits. Our analysis of these documents found measurement records (n = 924) largely based on field experiments (85%). Our results show strong evidence of the multiple benefits that some ecosystem-based practices (e.g., tree-based practices for coffee and no tillage for maize) can provide to support the adaptation to climate extremes of smallholder farming systems and enhance a farm’s natural assets (e.g., biodiversity, water, soil). We also found that the majority of research on practices in the region focused more on the socioeconomic dimension (54%) rather than on the capacity of practices to improve the natural assets of a smallholder farmers or reduce the impact of climate extremes. Given these knowledge gaps, we discuss the importance of a renovated investment in research to address existing knowledge gaps. Our concluding suggestions for future research include the need for systematizing existing knowledge from different sources (e.g., peer-reviewed, gray literature, farmers, extension agencies, etc.), and to assess the extent to which these practices can provide multiple benefits for smallholder farming systems by improving their wellbeing, reducing their vulnerability to different hydroclimatic extremes while also contributing to ecosystem services provision at the landscape level. Full article

(This article belongs to the Special Issue Climate-Smart Agriculture Practices for Reducing Production Risks for Smallholder Farmers)

► Show Figures

Figure 1

13 pages, 2599 KiB

Open AccessEditor’s ChoiceArticle

Effects of Long-Term Straw Return and Environmental Factors on the Spatiotemporal Variability of Soil Organic Matter in the Black Soil Region: A Case Study

by Yang Yan, Wenjun Ji, Baoguo Li, Guiman Wang, Bifeng Hu, Chao Zhang and Abdul Mounem Mouazen

Agronomy 2022, 12(10), 2532; https://doi.org/10.3390/agronomy12102532 - 17 Oct 2022

Cited by 9 | Viewed by 2119

Abstract

Exploring the effects of straw return and environmental factors on the spatiotemporal variation of soil organic matter (SOM) in black soil regions is essential for soil carbon sequestration research. However, studies seldom quantified the effects of long-term straw return on a long-term SOM [...] Read more.

Exploring the effects of straw return and environmental factors on the spatiotemporal variation of soil organic matter (SOM) in black soil regions is essential for soil carbon sequestration research. However, studies seldom quantified the effects of long-term straw return on a long-term SOM variation at a regional scale in typical black soil areas. The case was conducted in one of the three major black soil regions in the Northern Hemisphere, where the straw return policy has been implemented for a long time. The study obtained the SOM spatial distribution in 2007, 2009, 2012, 2015, and 2018 with approximately 9000 samples and analyzed the effects of soil types, texture, elevation, and human management on the spatiotemporal variation. The results indicated that from the 1980s to 2007, before the straw return policy implementation, the mean SOM content decreased from 24.38 g kg⁻¹ to 18.94 g kg⁻¹. In contrast, the mean SOM content gradually increased from 2007 to 2018 after implementing straw return practices. In addition, the area of SOM within 20–30 g kg⁻¹ increased gradually, with 32.2%, 40.5%, 50.2%, 49.4%, and 60.5% in 2007, 2009, 2012, 2015, and 2018, respectively. Surprisingly, the SOM within 30–40 g kg⁻¹ emerged in 2018. The results indicated that returning straw to the field might promote SOM accumulation. However, the SOM contents in Phaezems (19.25–21.82 g kg⁻¹) were lower than that in natural Phaezems (40–60 g kg⁻¹), indicating severe degradation. The clay content positively correlated to SOM and was a major explanatory variable for the response of SOM to straw return. Straw return practices are promising measures in the black soil region and are worth exploring more effective approaches to allow straw return to play a better role. Full article

(This article belongs to the Special Issue Soil Sustainability in the Anthropocene)

► Show Figures

Figure 1

16 pages, 2795 KiB

Open AccessEditor’s ChoiceArticle

A Systematic Study of Estimating Potato N Concentrations Using UAV-Based Hyper- and Multi-Spectral Imagery

by Jing Zhou, Biwen Wang, Jiahao Fan, Yuchi Ma, Yi Wang and Zhou Zhang

Agronomy 2022, 12(10), 2533; https://doi.org/10.3390/agronomy12102533 - 17 Oct 2022

Cited by 5 | Viewed by 2005

Abstract

Potato growth depends largely on nitrogen (N) availability in the soil. However, the shallow-root crop coupled with its common cultivation in coarse-textured soils leads to its poor N use efficiency. Fast and accurate estimations of potato tissue N concentrations are urgently needed to [...] Read more.

Potato growth depends largely on nitrogen (N) availability in the soil. However, the shallow-root crop coupled with its common cultivation in coarse-textured soils leads to its poor N use efficiency. Fast and accurate estimations of potato tissue N concentrations are urgently needed to assist the decision making in precision fertilization management. Remote sensing has been utilized to evaluate the potato N status by correlating spectral information with lab tests on leaf N concentrations. In this study, a systematic comparison was conducted to quantitatively evaluate the performance of hyperspectral and multispectral images in estimating the potato N status, providing a reference for the trade-off between sensor costs and performance. In the experiment, two potato varieties were planted under four fertilization rates with replicates. UAV images were acquired multiple times during the season with a narrow-band hyperspectral imager. Multispectral reflectance was simulated by merging the relevant narrow bands into broad bands to mimic commonly used multispectral cameras. The whole leaf total N concentration and petiole nitrate-N concentration were obtained from 160 potato leaf samples. A partial least square regression model was developed to estimate the two N status indicators using different groups of image features. The best estimation accuracies were given by reflectance of the full spectra with 2.2 nm narrow, with the coefficient of determination (R²) being 0.78 and root mean square error (RMSE) being 0.41 for the whole leaf total N concentration; while, for the petiole nitrate-N concentration, the 10 nm bands had the best performance (R² = 0.87 and RMSE = 0.13). Generally, the model performance decreased with an increase of the spectral bandwidth. The hyperspectral full spectra largely outperformed all three multispectral cameras, but there was no significant difference among the three brands of multispectral cameras. The results also showed that spectral bands in the visible regions (400–700 nm) were the most highly correlated with potato N concentrations. Full article

(This article belongs to the Special Issue Computer Vision for Intelligent Crop Identification and Crop Protection)

► Show Figures

Figure 1

12 pages, 999 KiB

Open AccessEditor’s ChoiceReview

Physiological Responses of Plants to Combined Drought and Heat under Elevated CO₂

by Lamis Osama Anwar Abdelhakim, Rong Zhou and Carl-Otto Ottosen

Agronomy 2022, 12(10), 2526; https://doi.org/10.3390/agronomy12102526 - 16 Oct 2022

Cited by 17 | Viewed by 2601

Abstract

Anthropogenic activities over the last century have caused rapid changes in environmental conditions through increasing CO₂ emissions in the atmosphere that contribute to global warming. Moreover, the increased global average temperature is linked with changes in the precipitation rate and distribution, resulting [...] Read more.

Anthropogenic activities over the last century have caused rapid changes in environmental conditions through increasing CO₂ emissions in the atmosphere that contribute to global warming. Moreover, the increased global average temperature is linked with changes in the precipitation rate and distribution, resulting in a negative impact on crop health and productivity. Plants in nature often experience combined stresses; therefore, they have developed adaptive mechanisms to cope with fluctuating environmental conditions. Thus, investigating plant responses under unfavorable environmental conditions will provide a better understanding of how crops can adapt and thereby assist in selecting climate-resilient crops that can withstand climate variability. This review highlights the main adaptive physiological and biochemical responses of crops grown under elevated CO₂ (eCO₂) and exposed to combined abiotic stresses (drought and heat). Moreover, the mitigation and limitation impact of elevated CO₂ on plants under the combination of stress is discussed. Full article

(This article belongs to the Collection Abiotic Stress Tolerance in Plants: Towards a Sustainable Agriculture)

► Show Figures

Figure 1

19 pages, 2400 KiB

Open AccessEditor’s ChoiceArticle

Impacts of Drought Stress on Water Use Efficiency and Grain Productivity of Rice and Utilization of Genotypic Variability to Combat Climate Change

by Tajamul Hussain, Nurda Hussain, Muhammad Tahir, Aamir Raina, Sobia Ikram, Saliha Maqbool, Muhammad Fraz Ali and Saowapa Duangpan

Agronomy 2022, 12(10), 2518; https://doi.org/10.3390/agronomy12102518 - 15 Oct 2022

Cited by 16 | Viewed by 3221

Abstract

Rice is an important cereal and drought stress is a critical abiotic stress that negatively influences the performance and productivity of rice crop, particularly under a changing climate scenario. The objectives of this study were to evaluate the impacts of drought stress on [...] Read more.

Rice is an important cereal and drought stress is a critical abiotic stress that negatively influences the performance and productivity of rice crop, particularly under a changing climate scenario. The objectives of this study were to evaluate the impacts of drought stress on grain productivity and water use efficiency of rice cultivars and to assess the genotypic variability among the tested cultivars. Two irrigation treatments including a control and drought stress were applied to the experiments during 2018–2019 and 2019–2020. The statistical evaluation included a comparison of means, genotypic and phenotypic coefficients of variation, path analysis, correlation assessment, hierarchical clustering of tested cultivars and principal component analysis. The results indicated that drought stress negatively affected the grain productivity of the rice cultivars. The grain productivity of the cultivars decreased, ranging between 21–45% and 21–52% in the first and second season, respectively. Similarly, water use efficiency was significantly decreased ranging between 7–53% and 21–55% during the first and the second season, respectively. The broad-sense heritability for grain productivity was differed under control and drought stress treatment, indicating that the chances of the transfer of grain-productivity-related traits could be affected during selection for stress tolerance. The correlation assessment indicated that the intensity of association among the evaluated parameters was higher under the control treatment. A maximum direct effect was observed by water consumption (1.76) under control whereas, by water use efficiency (1.09) under drought stress treatment on grain productivity in path analysis. Considering the water use efficiency as a desired trait for selection in path analysis, a maximum direct effect was observed by grain productivity under the control (0.68) and under drought treatment (0.88). Hom Pathum and Pathum Thani−1 were identified as highly tolerant cultivars in the hierarchical clustering and principal component analysis. It was concluded that the results obtained for the assessment of drought stress on grain productivity, water use efficiency and genotypic variability among these cultivars could be utilized in selection program for stress tolerance and the stress tolerant cultivars could be used for sustaining grain productivity to reduce the impacts of climate change. Full article

(This article belongs to the Special Issue Strategizing Agricultural Management for Climate Change Adaptation and Mitigation-Series II)

► Show Figures

Figure 1

23 pages, 6089 KiB

Open AccessEditor’s ChoiceArticle

Precision Variable-Rate Spraying Robot by Using Single 3D LIDAR in Orchards

by Limin Liu, Yajia Liu, Xiongkui He and Weihong Liu

Agronomy 2022, 12(10), 2509; https://doi.org/10.3390/agronomy12102509 - 14 Oct 2022

Cited by 15 | Viewed by 2326

Abstract

Automatic navigation (AN) is an essential component to ensure the safety of pesticide application in orchards, whereas precision variable-rate spraying (PVS) serves as an indispensable technology for reducing the application of pesticides and protecting the environment. At present, AN and PVS are not [...] Read more.

Automatic navigation (AN) is an essential component to ensure the safety of pesticide application in orchards, whereas precision variable-rate spraying (PVS) serves as an indispensable technology for reducing the application of pesticides and protecting the environment. At present, AN and PVS are not closely combined. In this case, a single three-dimension (3D) light detection and ranging (LIDAR) sensor is hereby adopted to sense the information of fruit trees around the robot and determine the region of interest (ROI). Moreover, two-dimensional (2D) processing is conducted over the point clouds within the ROI to obtain the center-of-mass coordinates of fruit trees, and determine the vertical distance of the robot to the center line of the fruit tree row (FTR) based on the FTR on both sides using the Random Sample Consensus (RANSAC) algorithm. Then, the robot is controlled to drive along the center line of the FTR. At the same time, the speed and position of the robot are determined by the encoder and inertial measurement unit (IMU), and the IMU corrects the information collected from the zoned canopy of the fruit trees. The results present a lateral deviation (LD) of less than 22 cm and a course deviation (CD) of less than 4.02° during AN. Compared with the traditional spraying (TS), the PVS applies 32.46%, 44.34% and 58.14% less pesticide application, air drift and ground loss, respectively. With the spraying effect guaranteed, the single 3D LIDAR, the encoder and IMU realize the AN and PVS of the robot, reduce the volume of pesticide application, ground loss and air drift, and effectively control the pollution caused by pesticides to the environment. Full article

(This article belongs to the Section Agricultural Biosystem and Biological Engineering)

► Show Figures

Figure 1

23 pages, 5345 KiB

Open AccessEditor’s ChoiceArticle

Soil Chemical Properties Depending on Fertilization and Management in China: A Meta-Analysis

by Shengnan Jia, Ding Yuan, Wenwen Li, Wei He, Sajjad Raza, Yakov Kuzyakov, Kazem Zamanian and Xiaoning Zhao

Agronomy 2022, 12(10), 2501; https://doi.org/10.3390/agronomy12102501 - 13 Oct 2022

Cited by 11 | Viewed by 2979

Abstract

The long-term overuse of fertilizers negatively affects soil chemical properties and health, causing unsustainable agricultural development. Although many studies have focused on the effects of long-term fertilization on soil properties, few comparative and comprehensive studies have been conducted on fertilization management over the [...] Read more.

The long-term overuse of fertilizers negatively affects soil chemical properties and health, causing unsustainable agricultural development. Although many studies have focused on the effects of long-term fertilization on soil properties, few comparative and comprehensive studies have been conducted on fertilization management over the past 35 years in China. This meta-analysis (2058 data) evaluated the effects of the fertilizer, climate, crop types, cultivation duration and soil texture on the soil chemical properties of Chinese croplands. NPKM (NPK fertilizers + manure) led to the highest increase in pH (−0.1), soil organic carbon (SOC) (+67%), total nitrogen (TN) (+63%), alkali-hydrolysable nitrogen (AN) (+70%), total phosphorus (TP) (+149%) and available potassium (AK) (+281%) compared to the unfertilized control, while the sole nitrogen fertilizer (N) led to the lowest increase. The SOC (+115%) and TN (+84%) showed the highest increase under the influence of NPKM in an arid region. The increase in the chemical properties was higher in unflooded crops, with the maximum increase in the wheat–maize rotation, compared to rice, under NPKM. The SOC and TN increased faster under the influence of organic fertilizers (manure or straw) compared to mineral fertilization. Fertilizers produced faster effects on the change in the SOC and TN in sandy loam compared to the control. Fertilizers showed the highest and lowest effects on change in pH, organic C to total N ratio (C/N), TP and TK in clay loam with the cultivation duration. NPKM greatly increased the C/N compared to NPK in an arid region by 1.74 times and in wheat by 1.86 times. Reaching the same SOC increase, the lowest TN increase was observed in wheat, and the lowest increase in TP and AK was observed in rice, compared to the other crops. These results suggest that organic fertilizers (manure or straw) play important roles in improving soil fertility and in acidification. NPKM greatly increased the potential for soil C sequestration in wheat and in the arid region. The small increases in TP and TK can increase the SOC in rice and in the humid region. Therefore, considering the crop types and climatic conditions, reduced fertilization and the combination of mineral fertilizers with manure may be the best ways to avoid agricultural soil deterioration and increase soil carbon sequestration. Full article

(This article belongs to the Special Issue Soil Carbon Pools, Turnover, and Distribution Patterns in Agroecosystems)

► Show Figures

Figure 1

21 pages, 23526 KiB

Open AccessEditor’s ChoiceArticle

Automatic Estimation of Apple Orchard Blooming Levels Using the Improved YOLOv5

by Zhaoying Chen, Rui Su, Yuliang Wang, Guofang Chen, Zhiqiao Wang, Peijun Yin and Jinxing Wang

Agronomy 2022, 12(10), 2483; https://doi.org/10.3390/agronomy12102483 - 12 Oct 2022

Cited by 13 | Viewed by 2330

Abstract

The estimation of orchard blooming levels and the determination of peak blooming dates are very important because they determine the timing of orchard flower thinning and are essential for apple yield and quality. In this paper, we propose an orchard blooming level estimation [...] Read more.

The estimation of orchard blooming levels and the determination of peak blooming dates are very important because they determine the timing of orchard flower thinning and are essential for apple yield and quality. In this paper, we propose an orchard blooming level estimation method for global-level and block-level blooming level estimation of orchards. The method consists of a deep learning-based apple flower detector, a blooming level estimator, and a peak blooming day finding estimator. The YOLOv5s model is used as the apple flower detector, which is improved by adding a coordinate attention layer and a small object detection layer and by replacing the model neck with a bidirectional feature pyramid network (BiFPN) structure to improve the performance of the apple flower detector at different growth stages. The robustness of the apple flower detector under different light conditions and the generalization across years was tested using apple flower data collected in 2021–2022. The trained apple flower detector achieved a mean average precision of 77.5%. The blooming level estimator estimated the orchard blooming level based on the proportion of flowers detected at different growth stages. Statistical results show that the blooming level estimator follows the trend of orchard blooming levels. The peak blooming day finding estimator successfully positioned the peak blooming time and provided information for the flower thinning timing decision. The method described in this paper is able to provide orchardists with accurate information on apple flower growth status and is highly automated. Full article

(This article belongs to the Special Issue Application of Deep Learning in Precise Analysis of Agricultural Crops)

► Show Figures

Figure 1

31 pages, 3400 KiB

Open AccessFeature PaperEditor’s ChoiceReview

Computer Vision and Deep Learning for Precision Viticulture

by Lucas Mohimont, François Alin, Marine Rondeau, Nathalie Gaveau and Luiz Angelo Steffenel

Agronomy 2022, 12(10), 2463; https://doi.org/10.3390/agronomy12102463 - 11 Oct 2022

Cited by 17 | Viewed by 4114

Abstract

During the last decades, researchers have developed novel computing methods to help viticulturists solve their problems, primarily those linked to yield estimation of their crops. This article aims to summarize the existing research associated with computer vision and viticulture. It focuses on approaches [...] Read more.

During the last decades, researchers have developed novel computing methods to help viticulturists solve their problems, primarily those linked to yield estimation of their crops. This article aims to summarize the existing research associated with computer vision and viticulture. It focuses on approaches that use RGB images directly obtained from parcels, ranging from classic image analysis methods to Machine Learning, including novel Deep Learning techniques. We intend to produce a complete analysis accessible to everyone, including non-specialized readers, to discuss the recent progress of artificial intelligence (AI) in viticulture. To this purpose, we present work focusing on detecting grapevine flowers, grapes, and berries in the first sections of this article. In the last sections, we present different methods for yield estimation and the problems that arise with this task. Full article

(This article belongs to the Special Issue Imaging Technology for Detecting Crops and Agricultural Products)

► Show Figures

Figure 1

17 pages, 1457 KiB

Open AccessEditor’s ChoiceArticle

Nitrogen Fertilization and Glyphosate as a Growth Regulator: Effects on the Nutritional Efficiency and Nutrient Balance in Emerald Grass

by Raíssa Pereira Dinalli, Salatiér Buzetti, Rodolfo de Niro Gazola, Regina Maria Monteiro de Castilho, Arshad Jalal, Fernando Shintate Galindo and Marcelo Carvalho Minhoto Teixeira Filho

Agronomy 2022, 12(10), 2473; https://doi.org/10.3390/agronomy12102473 - 11 Oct 2022

Cited by 1 | Viewed by 1293

Abstract

Nitrogen (N) is one of the promising nutrients for lawn growth and is required for the lawn’s proper growth and development, but it also increases mowing frequency. Glyphosate herbicide application in sub-doses, as a growth regulator, can reduce the maintenance costs without any [...] Read more.

Nitrogen (N) is one of the promising nutrients for lawn growth and is required for the lawn’s proper growth and development, but it also increases mowing frequency. Glyphosate herbicide application in sub-doses, as a growth regulator, can reduce the maintenance costs without any adverse reduction in the density and nutritional status of grasses. The objective of this study was to evaluate the influences of nitrogen and glyphosate doses on the growth, aesthetic quality and nutritional status of emerald grass (Zoysia japonica Steud.). The experiment was conducted at the Research and Extension Education Farm of São Paulo State University (UNESP), Ilha Solteira, SP, Brazil, in an Ultisol. The experiment was designed as a randomized block with 12 treatments arranged in a 3 × 4 factorial scheme with 4 replications, comprised of a control (without N), 15 and 30 g N m⁻² of urea, applied in five splits annually, and glyphosate doses (0, 200, 400 and 600 g ha⁻¹ of the active ingredient, a.i.). The split N fertilization at the rate of 15 g m⁻² and glyphosate at the dose of 400 g ha⁻¹ maintained nutritional status of emerald grass. Nitrogen at the rate 15 g N m⁻² (in five splits per year) was observed to produce lower growth traits, an adequate aesthetic quality and longer stability of the nutrients in emerald grasses through lower exportation, with removal of “clipping” after mowing. In addition, glyphosate, at the dose of 400 g a.i. ha⁻¹, was efficient in reducing the leaf area, plant height, shoot dry matter and total dry matter by 18.3, 14.7, 6.8 and 8.1%, respectively, as compared to the control. However, this dose did not impair the coloration and resulted in a lower exportation of nutrients by reducing the need to replenish by fertilization. Therefore, fertilization with 15 g N m⁻², associated with application of 400 g a.i. ha⁻¹ of glyphosate, is recommended for emerald grass in the tropical savannah of Brazil. Full article

► Show Figures

Figure 1

17 pages, 2153 KiB

Open AccessEditor’s ChoiceArticle

Micronutrients Foliar and Drench Application Mitigate Mango Sudden Decline Disorder and Impact Fruit Yield

by Ummadud din Umar, Niaz Ahmed, Muhammad Zeshan Zafar, Ateequr Rehman, Syed Atif Hasan Naqvi, Muhammad Asif Zulfiqar, Muhammad Tariq Malik, Baber Ali, Muhammad Hamzah Saleem and Romina Alina Marc

Agronomy 2022, 12(10), 2449; https://doi.org/10.3390/agronomy12102449 - 10 Oct 2022

Cited by 23 | Viewed by 2840

Abstract

Mango sudden death (MSD) or quick decline (QD) is the most destructive disease found in mango orchards of Pakistan and is characterized by collapse of the vascular system by Ceratocystis fimbriata and Lasiodiplodia theobromae. Cultural practices, chemicals, and biological control are the [...] Read more.

Mango sudden death (MSD) or quick decline (QD) is the most destructive disease found in mango orchards of Pakistan and is characterized by collapse of the vascular system by Ceratocystis fimbriata and Lasiodiplodia theobromae. Cultural practices, chemicals, and biological control are the most valuable tools for the management of MSD, but the role of micronutrient deficiencies has remained an area that is heavily ignored by the farming community. To study the impact of micronutrients, four mango orchards were selected at different locations where different combinations of micronutrients, i.e., Zinc (Zn), Boran (B), and Copper (Cu) in the form of Zinc sulphate (ZnSO₄), Borax/Boric acid (H₃BO₃), and Copper Sulphate (CuSO₄), were applied both foliar and in drench along with the recommended doses of Nitrogen: Phosphorous: Potassium (NPK), and Farmyard manure (FYM), respectively. The quantities of micronutrients were determined from the soil and leaves before and after application of the treatments. The impact of micronutrients was measured in terms of reduction in disease severity and increase in fruit yield. The results revealed that the application of all three micronutrients both in soil drench and in foliar form significantly decreased the disease severity at three locations and increased the yield in all four mango orchards. Application of ZnSO₄ (0.8%), +H₃BO₃ (0.8%), +CuSO₄ (0.5%) and as soil drench ZnSO₄ (400 g) + Borax (200 g) + CuSO₄ 200 g plant⁻¹ proved to be the best treatments, with an average of 12.88 and 14.03% reduction in disease severity and with an average yield of 128 and 119 kg, respectively. The application of micronutrients would be a promising solution in an integrated disease management program used to tackle MSD. Full article

(This article belongs to the Special Issue Perspectives and Challenges for Sustainable Management of Fruit and Foliar Diseases)

► Show Figures

Figure 1

19 pages, 2204 KiB

Open AccessEditor’s ChoiceArticle

Insight into the Root Transcriptome of a Boron-Tolerant Triticum zhukovskyi Genotype Grown under Boron Toxicity

by Anamika Pandey, Mohd. Kamran Khan, Mehmet Hamurcu, Marian Brestic, Ali Topal and Sait Gezgin

Agronomy 2022, 12(10), 2421; https://doi.org/10.3390/agronomy12102421 - 06 Oct 2022

Cited by 23 | Viewed by 1631

Abstract

Boron (B) toxicity is an important abiotic stress that drastically damages agricultural production worldwide, mostly in arid regions. Several studies have reported large losses in wheat due to high B in arable land. The identification of different B-toxicity-tolerant wheat germplasm and using them [...] Read more.

Boron (B) toxicity is an important abiotic stress that drastically damages agricultural production worldwide, mostly in arid regions. Several studies have reported large losses in wheat due to high B in arable land. The identification of different B-toxicity-tolerant wheat germplasm and using them in breeding programs to develop tolerant cultivars is a potential solution to B toxicity. However, tolerance to B toxicity in such germplasm largely relies on the molecular changes in plants under B toxicity at the transcriptome level. Thus, the aim of this study is to determine the transcriptomic response of the roots of a B-toxicity-tolerant Triticum zhukovskyi genotype, PI296968, grown in a highly toxic B environment (10 mM B) in comparison with a control (3.1 μM B) treatment. T. zhukovskyi is a hexaploid wheat species forming a separate lineage from the main wheat lineage and can be a good source of genes for various stresses. However, it has been hardly explored for tolerance to any abiotic stress condition. This study is the first in the literature reporting the B toxicity tolerance of a T. zhukovskyi genotype along with the molecular changes occurring in it under B toxicity as compared to the control treatment. In the present study, 5992 genes were found to be significantly differentially expressed, with 1679 and 4313 up- and down-regulated genes, respectively. A number of transcription factors and pathways were identified to be significantly involved in the B toxicity response of the T. zhukovskyi genotype. A total of 12582 novel transcripts were determined in the study, with 9238 and 3344 coding and noncoding transcripts, respectively. The results not only suggest several candidate genes that can be further studied to improve wheat tolerance to B toxicity in upcoming breeding programs, but also enhance the understanding of the regulatory and molecular processes behind the wheat response to B toxicity. Further experiments are suggested to functionally characterize the identified high-B-responsive genes to confirm their role in providing B toxicity tolerance to the plants. Full article

(This article belongs to the Special Issue Omics Methods for Probing the Abiotic Stress Responses in Plants)

► Show Figures

Figure 1

19 pages, 4118 KiB

Open AccessEditor’s ChoiceArticle

Deep Learning-Based Leaf Disease Detection in Crops Using Images for Agricultural Applications

by Andrew J., Jennifer Eunice, Daniela Elena Popescu, M. Kalpana Chowdary and Jude Hemanth

Agronomy 2022, 12(10), 2395; https://doi.org/10.3390/agronomy12102395 - 03 Oct 2022

Cited by 62 | Viewed by 30085

Abstract

The agricultural sector plays a key role in supplying quality food and makes the greatest contribution to growing economies and populations. Plant disease may cause significant losses in food production and eradicate diversity in species. Early diagnosis of plant diseases using accurate or [...] Read more.

The agricultural sector plays a key role in supplying quality food and makes the greatest contribution to growing economies and populations. Plant disease may cause significant losses in food production and eradicate diversity in species. Early diagnosis of plant diseases using accurate or automatic detection techniques can enhance the quality of food production and minimize economic losses. In recent years, deep learning has brought tremendous improvements in the recognition accuracy of image classification and object detection systems. Hence, in this paper, we utilized convolutional neural network (CNN)-based pre-trained models for efficient plant disease identification. We focused on fine tuning the hyperparameters of popular pre-trained models, such as DenseNet-121, ResNet-50, VGG-16, and Inception V4. The experiments were carried out using the popular PlantVillage dataset, which has 54,305 image samples of different plant disease species in 38 classes. The performance of the model was evaluated through classification accuracy, sensitivity, specificity, and F1 score. A comparative analysis was also performed with similar state-of-the-art studies. The experiments proved that DenseNet-121 achieved 99.81% higher classification accuracy, which was superior to state-of-the-art models. Full article

(This article belongs to the Special Issue Imaging Technology for Detecting Crops and Agricultural Products)

► Show Figures

Figure 1

17 pages, 1399 KiB

Open AccessEditor’s ChoiceReview

Maize Breeding: From Domestication to Genomic Tools

by Leon Muntean, Andreea Ona, Ioana Berindean, Ionuț Racz and Sorin Muntean

Agronomy 2022, 12(10), 2365; https://doi.org/10.3390/agronomy12102365 - 30 Sep 2022

Cited by 2 | Viewed by 4002

Abstract

Maize will continue to expand and diversify as an industrial resource and a feed and fuel crop in the near future. The United Nations estimate that in 2050 the global population will reach 9.7 billion people. In this context, food security is increasingly [...] Read more.

Maize will continue to expand and diversify as an industrial resource and a feed and fuel crop in the near future. The United Nations estimate that in 2050 the global population will reach 9.7 billion people. In this context, food security is increasingly being discussed. Additionally, another threat to food security is global warming. It is predicted that both the quantity and the quality of crops will be seriously affected by climate change in the near future. Scientists and breeders need to speed up the process of creating new maize cultivars that are resistant to climate stress without diminishing yield or quality. The present paper provides a brief overview of some of the most important genomics tools that can be used to develop high-performance and well-adapted hybrids of maize and also emphasizes the contribution of bioinformatics to an advanced maize breeding. Genomics tools are essential for a precise, fast, and efficient breeding of crops especially in the context of climate challenges. Maize breeders are able now to develop new cultivars with better traits more easily as a result of the new genomic approaches, either by aiding the selection process or by increasing the available diversity through precision breeding procedures. Furthermore, the use of genomic tools may in the future represent a way to accelerate the processes of de novo domestication of the species. Full article

► Show Figures

Figure 1

14 pages, 2072 KiB

Open AccessEditor’s ChoiceArticle

Assessing the Population Structure of Colorado Potato Beetle Populations in Croatia Using Genetic and Geometric Morphometric Tools

by Martina Kadoić Balaško, Renata Bažok, Katarina M. Mikac, Hugo A. Benítez, Margarita Correa and Darija Lemic

Agronomy 2022, 12(10), 2361; https://doi.org/10.3390/agronomy12102361 - 30 Sep 2022

Cited by 1 | Viewed by 1672

Abstract

The Colorado potato beetle (CPB, Leptinotarsa decemlineata Say) is one of the most successful invasive species worldwide. It has been present in Croatia since 1947, where it has caused significant damage to potato plants and developed resistance to several insecticides. Our study is [...] Read more.

The Colorado potato beetle (CPB, Leptinotarsa decemlineata Say) is one of the most successful invasive species worldwide. It has been present in Croatia since 1947, where it has caused significant damage to potato plants and developed resistance to several insecticides. Our study is the first attempt to investigate the population structure of CPBs in Croatia. SNP and GM techniques provided us with data about the population structure of the CPB population. A Bayesian model-based clustering algorithm implemented in STRUCTURE, principal component analysis (PCA), and discriminant analysis of principal components (DAPC) were used to analyze the genetic structure of CPBs. For the morphometric analysis, the hindwing shape of the same CPB individuals was examined using wing venation patterns. We detected the low genetic and phenotypic variabilities of CPB populations and the presence of a single panmictic population in the study area, well adapted to different environmental conditions, indicating high phenotypic plasticity. Due to such exceptional adaptation of the CPB population, it is necessary to implement an area-wide approach in future pest control management. Full article

► Show Figures

Figure 1

22 pages, 5646 KiB

Open AccessFeature PaperEditor’s ChoiceArticle

Designing Integrated Systems for the Low Rainfall Zone Based on Grazed Forage Shrubs with a Managed Interrow

by Andrew P. Smith, Eric Zurcher, Rick S. Llewellyn and Hayley C. Norman

Agronomy 2022, 12(10), 2348; https://doi.org/10.3390/agronomy12102348 - 29 Sep 2022

Viewed by 1522

Abstract

Managed plantations of saltbush have the potential to increase the productivity and climate resilience of the farming systems of the low rainfall areas of the world, where livestock are important. The objective was to dynamically simulate the behaviour of grazing saltbush plantations with [...] Read more.

Managed plantations of saltbush have the potential to increase the productivity and climate resilience of the farming systems of the low rainfall areas of the world, where livestock are important. The objective was to dynamically simulate the behaviour of grazing saltbush plantations with a new modelling capacity in the APSIM framework to enable the dynamic grazing of forage systems. Scenarios simulated included: the choice of plant species growing in the interrow area between shrub-rows, density of saltbush spatial arrangement, locations with different climates and soils, and grazing strategy by sheep. Comparisons of scenarios across systems were insightful during rainfall years when the shrub systems are of high value (i.e., driest/lowest 20% rainfall years in the simulation period). Overall, the efficient grazing of shrubs by dry sheep with little supplementary feeding, required the availability of a large amount of low quality interrow. Shrub plantations with an interrow of standing oats required least supplementation. Summer grazing was the optimal time for grazing shrub plantations in low rainfall years. Plantations with more shrubs relative to interrow increased the need for supplementary feeding but reduced the variation between years. This is one of the first uses of systems modelling to explore forage shrub system designs that maximise the grazing value of shrub plus interrow. Full article

(This article belongs to the Section Innovative Cropping Systems)

► Show Figures

Figure 1

20 pages, 3144 KiB

Open AccessEditor’s ChoiceArticle

New Antifungal Compound, 6-Pentyl-α-Pyrone, against the Maize Late Wilt Pathogen, Magnaporthiopsis maydis

by Ofir Degani and Asaf Gordani

Agronomy 2022, 12(10), 2339; https://doi.org/10.3390/agronomy12102339 - 28 Sep 2022

Cited by 12 | Viewed by 2474

Abstract

6-pentyl-α-pyrone (6-PP) is a powerful Magnaporthiopsis maydis antifungal compound, recently discovered when the potent growth medium of Trichoderma asperellum was analyzed. Despite its high potential in plate assay, it was not inspected for plant treatment prevention. Late wilt disease, caused by the fungus [...] Read more.

6-pentyl-α-pyrone (6-PP) is a powerful Magnaporthiopsis maydis antifungal compound, recently discovered when the potent growth medium of Trichoderma asperellum was analyzed. Despite its high potential in plate assay, it was not inspected for plant treatment prevention. Late wilt disease, caused by the fungus M. maydis, threatens commercial maize production in high-risk areas. Thus, the search for control options against the pathogen is one of the top priorities in Israel, Egypt, and other countries. Disease-resistant maize genotypes can reduce the damages. Yet, aggressive variants of the fungus can overcome host resistance. The current study aimed at inspecting T. asperellum and its secreted metabolite, pure 6-PP, against the pathogen in plants over a full growth period. First, adding T. asperellum directly to seeds with sowing provides significant protection to sprouts (up to 42 days) in a growth room, with more than two-fold growth promotion and reduced pathogen root infection (detected by real-time PCR). The same procedure applied in a commercial field was less beneficial in rescuing the plants’ growth and yield. Still, it reduced the cobs’ symptoms by 11% and resulted in nine-fold lower levels of the pathogen’s DNA in the stem tissue. Second, the T. asperellum purified 6-PP compound (30 µg/seed) was used in seed coating and tested against the T. asperellum secretory metabolites’ crude (diluted to 50%). At the season’s end, these treatments improved plant biomass by 90–120% and cob weight by 60%. Moreover, the treatments significantly (p < 0.05) reduced the symptoms (up to 20%) and pathogen infection (94–98%). The current study’s results reveal the potential of 6-PP as a new fungicide against M. maydis. Such a treatment may protect maize plants from other soil diseases. Full article

(This article belongs to the Special Issue Research Progress on Pathogenicity of Fungus in Crop)

► Show Figures

Graphical abstract

12 pages, 887 KiB

Open AccessEditor’s ChoiceArticle

Agronomic Efficiency of Phosphorus Fertilisers Recovered from Milk Processing Waste

by Shane McIntosh, Terry Rose, Andrew Rose, Lee Kearney and Dirk Erler

Agronomy 2022, 12(10), 2341; https://doi.org/10.3390/agronomy12102341 - 28 Sep 2022

Cited by 2 | Viewed by 1302

Abstract

The recovery of phosphorus (P) from milk processing flotation sludges (MFS) using pyrolysis can contribute to a sustainable reuse of P by converting waste to fertiliser. The objectives of this study were to quantify the recovery and transformation of P following MFS pyrolysis [...] Read more.

The recovery of phosphorus (P) from milk processing flotation sludges (MFS) using pyrolysis can contribute to a sustainable reuse of P by converting waste to fertiliser. The objectives of this study were to quantify the recovery and transformation of P following MFS pyrolysis and compare the efficacy of raw and pyrolysed MFS as organic P fertilisers. Phosphorus retention in biochars was high (98 ± 0.73% yield), leading to the enrichment of P relative to the raw MFS by a factor of 4.3–4.5. Pyrolysis of the MFS at 450 °C led to a 3-fold increase in the proportion of P in the HCl-extractable fraction (65 ± 0.32%), a 2-fold reduction in NaOH-P (30 ± 2.1%), and negligible amounts of P in the H₂O-P and NaHCO₃-P fractions. The bioavailability of P in raw MFS and 450 °C biochar was compared to a soluble P fertiliser in P-limiting plant bioassays. In the short-term (70 day) trial where ryegrass was grown on three soil types (Arenosol, Vertisol or Ferralsol), biochar MFS showed higher efficacy as a P fertiliser than raw MFS in the acidic Ferralsol, whereas the opposite response was observed in the near-neutral Arenosol. In the Vertisol, neither the raw MFS nor biochar produced more cumulative biomass or P uptake than any of the nil P controls. Over a longer 200-day period, raw MFS and biochar applied to the Arenosol were about 20% as efficient at providing P to ryegrass plants as the water-soluble K₂PO₄, suggesting that higher application rates of MFS or biochar would be required to match synthetic fertilisers in the short term. Full article

(This article belongs to the Special Issue Agricultural Valorization of Agro-Industrial By-Products: From Waste to Value)

► Show Figures

Graphical abstract

16 pages, 58236 KiB

Open AccessEditor’s ChoiceArticle

Fabrication of Copper Oxide Nanoparticles Using Passiflora edulis Extract for the Estimation of Antioxidant Potential and Photocatalytic Methylene Blue Dye Degradation

by Amina Yasin, Urooj Fatima, Sammia Shahid, Sana Mansoor, Hina Inam, Mohsin Javed, Shahid Iqbal, Hamad Alrbyawi, Hamoud H. Somaily, Rami Adel Pashameah, Eman Alzahrani and Abd-ElAziem Farouk

Agronomy 2022, 12(10), 2315; https://doi.org/10.3390/agronomy12102315 - 27 Sep 2022

Cited by 17 | Viewed by 4054

Abstract

In the present work, copper oxide nanoparticles have been fabricated by using a biological method. Copper oxide nanoparticles (CuO NPs) have received more attention than other metal oxides due to their distinctive properties and applications. Plant-mediated synthesis of nanoparticles has gained the attention [...] Read more.

In the present work, copper oxide nanoparticles have been fabricated by using a biological method. Copper oxide nanoparticles (CuO NPs) have received more attention than other metal oxides due to their distinctive properties and applications. Plant-mediated synthesis of nanoparticles has gained the attention of researchers because of its simple and ecologically sustainable approach. The biosynthesis of CuO NPs included the use of Passiflora edulis leaf extract that acts as a stabilizing and reducing agent. A non-toxic, cost-effective, and ecologically acceptable method was the use of plant leaf extract in the biogenesis of nanoscale materials. UV-vis, SEM, FTIR, and XRD techniques were used to examine the biologically produced copper oxide nanoparticles. The findings of the SEM examination, which gives morphological information, demonstrate that the synthesized NPs have a spherical shape and have an average particle size of between 60 and 65 nm. CuO has been further investigated in the current study as a photo-catalyst in the methylene blue (MB) dye degradation and as an antioxidant in free radical scavenging activities. The decolorization efficiency was approximately 93% after 160 min. Furthermore, CuO nanoparticles were tested for antioxidant performance by scavenging 2, 2-diphenyl-1-picrylhydrazyl hydrate free radicals (DPPH) and evaluated by UV-Vis spectroscopy. The result showed that biologically synthesized CuO NPs can be used as an effective antioxidant. The half maximal inhibitory concentration IC50 of copper oxide nanoparticles was found to be in the range of 0.13–0.20. Full article

(This article belongs to the Special Issue Phytochemicals of Edible Plants—Volume II)

► Show Figures

Figure 1

13 pages, 2547 KiB

Open AccessEditor’s ChoiceCommunication

Nitrous Oxide Emission and Grain Yield in Chinese Winter Wheat–Summer Maize Rotation: A Meta-Analysis

by Chengcheng Yao, Xiongwei Wu, He Bai and Jiangxin Gu

Agronomy 2022, 12(10), 2305; https://doi.org/10.3390/agronomy12102305 - 26 Sep 2022

Cited by 6 | Viewed by 2472

Abstract

A systematic understanding of nitrous oxide (N₂O) emission and grain yield in winter wheat–summer maize rotation, one of the most important cereal cropping systems in China, is still lacking. The primary aim of this study was to quantify the N₂ [...] Read more.

A systematic understanding of nitrous oxide (N₂O) emission and grain yield in winter wheat–summer maize rotation, one of the most important cereal cropping systems in China, is still lacking. The primary aim of this study was to quantify the N₂O emissions and grain yield, as well as responses to mitigation strategies, in this intensively managed agroecosystem. We conducted a pairwise meta-analysis by compiling a comprehensive dataset of annual N₂O emissions (n = 530) and grain yields (n = 352) from peer−reviewed publications. The N₂O emissions increased with nitrogen (N) fertilizer input rates following a linear model (r² = 0.295, p < 0.001), giving a specific emission coefficient and background emission of 0.71% and 0.5 kg N ha⁻¹ yr⁻¹, respectively. The grain yields responded to the N input rates following a linear-plateau model (r² = 0.478, p < 0.001), giving an optimal N input rate and maximum grain yield of 405 kg N ha⁻¹ yr⁻¹ and 15.5 t ha⁻¹ yr⁻¹, respectively. The meta-analyses revealed that reducing N fertilizers (approximately 50% of the full N input), water-saving irrigation, reduced or no tillage, and applying enhanced efficiency fertilizers significantly decreased N₂O emissions (range: −45% to −9%) and increased or did not impact grain yields (range: −1% to 3%). We recommend that reducing agricultural inputs (i.e., N fertilizers, irrigation, and tillage) is a feasible N₂O mitigation strategy in the intensively managed winter wheat–summer maize rotation that can be employed without additional environmental risks. Full article

(This article belongs to the Special Issue Effects of Tillage, Cover Crop and Crop Rotation on Soil)

► Show Figures

Figure 1

15 pages, 2177 KiB

Open AccessEditor’s ChoiceArticle

The Effect of Rotational Cropping of Industrial Hemp (Cannabis sativa L.) on Rhizosphere Soil Microbial Communities

by Lili Tang, Chao Fan, Hongmei Yuan, Guangwen Wu, Jing Sun and Shuquan Zhang

Agronomy 2022, 12(10), 2293; https://doi.org/10.3390/agronomy12102293 - 24 Sep 2022

Cited by 2 | Viewed by 3317

Abstract

Crop rotation affects soil properties and soil microbial diversity and structure. Currently, it is not well understood how soil microbial diversity changes following different crop rotation systems of industrial hemp, an ancient and economically important crop. Therefore, these changes were analyzed in this [...] Read more.

Crop rotation affects soil properties and soil microbial diversity and structure. Currently, it is not well understood how soil microbial diversity changes following different crop rotation systems of industrial hemp, an ancient and economically important crop. Therefore, these changes were analyzed in this study. Our results showed that different rotation systems significantly affected the wilt disease incidence, plant height, yield, soil physicochemical properties and soil microbial communities in the greenhouse. The rotation systems used in this study significantly reduced the plant mortality and increased the yield compared with a monoculture system. The levels of alkaline hydrolysis and available phosphorus in the soil decreased significantly compared with a monoculture cropping system. Using MiSeq high-throughput sequencing, we showed that the soil diversity and number of bacteria and fungi were significantly higher for rotation systems and controls compared to the monoculture system. The relative abundance of pathogens increased with a monoculture system. Redundancy analysis suggests that soil properties may also affect the soil microbial composition. Taken together, different rotation systems used in this study significantly decreased the disease incidence, increased plant yields and increased soil microbial diversity compared with monoculture for industrial hemp. We believe that applying these rotation systems is an efficient and eco-friendly approach to control soil borne pathogenic diseases and increase floral yields. Full article

► Show Figures

Figure 1

13 pages, 3744 KiB

Open AccessEditor’s ChoiceArticle

UAV Multispectral Data: A Reliable Approach for Managing Phosphate-Solubilizing Bacteria in Common Bean

by Antonia Erica Santos de Souza, Marcelo Rodrigues Barbosa Júnior, Bruno Rafael de Almeida Moreira, Rouverson Pereira da Silva and Leandro Borges Lemos

Agronomy 2022, 12(10), 2284; https://doi.org/10.3390/agronomy12102284 - 23 Sep 2022

Cited by 3 | Viewed by 1764

Abstract

Remote sensing can offer stakeholders opportunities to make precise and accurate decisions on agricultural activities. For instance, farmers can exploit aircraft systems to acquire survey-level, high-resolution imagery data for crop and soil management. Therefore, the objective of this study was to analyze whether [...] Read more.

Remote sensing can offer stakeholders opportunities to make precise and accurate decisions on agricultural activities. For instance, farmers can exploit aircraft systems to acquire survey-level, high-resolution imagery data for crop and soil management. Therefore, the objective of this study was to analyze whether an unmanned aerial vehicle (UAV) allows for the assessment and monitoring of biofertilization of the common bean upon vegetation indices (VIs). The biological treatment of the legume crop included its inoculation with phosphate-solubilizing bacteria (PSB), namely Bacillus subtilis and B. megaterium. Indicators of photosynthetic performance, such as chlorophylls (a and b) and carotenoids, were measured from actively growing leaves to determine effectiveness. In addition, images were acquired in the field, both spatially and temporally, to establish functional relationships between biometric and computational features. Microorganisms manifested as growth-promoting agents to the crop as they significantly increased its quantities of light-harvesting pigments. VIs allowed for predicting their impact on photosynthetic performance, making them on-site markers of PSB. Therefore, this research can provide insights into the remote, non-destructive mapping of spectral changes in the common bean upon the application of PSB. Imagery data from UAV would enable producers to generate information on the crop to intervene in the field at the right time and place for improved utilization of biofertilizers. Full article

(This article belongs to the Special Issue Research Advances in Digital Technologies to Improve Agricultural Productivity)

► Show Figures

Graphical abstract

20 pages, 1912 KiB

Open AccessEditor’s ChoiceArticle

Salinity Effect on Plant Growth Parameters and Fruit Bioactive Compounds of Two Strawberry Cultivars, Coupled with Environmental Conditions Monitoring

by Nikoleta-Kleio Denaxa, Aggeliki Nomikou, Nikolaos Malamos, Eleni Liveri, Petros Anargyrou Roussos and Vasileios Papasotiropoulos

Agronomy 2022, 12(10), 2279; https://doi.org/10.3390/agronomy12102279 - 23 Sep 2022

Cited by 14 | Viewed by 2778

Abstract

Salinity stress is one of the most vital abiotic stresses, impairing the productivity of crops in both irrigated and dry areas. A pot experiment was carried out in a greenhouse environment, aiming to examine the relevant tolerances and evaluate the effect of salinity [...] Read more.

Salinity stress is one of the most vital abiotic stresses, impairing the productivity of crops in both irrigated and dry areas. A pot experiment was carried out in a greenhouse environment, aiming to examine the relevant tolerances and evaluate the effect of salinity stress on plant growth, fruit physiological, and quality traits of two strawberry cultivars, Camarosa and Rociera. The plants were irrigated with water with electrical conductivity (EC) of 0.4 dS m⁻¹ (control), or with a salt solution with either ECs 2 dS m⁻¹ (moderate salt stress) or 4 dS m⁻¹ (elevated salt stress). Furthermore, several meteorological parameters, as well as soil moisture, were monitored inside the greenhouse. The results showed that salinity induced osmotic stress, water deprivation, and toxic effects, affecting the growth parameters and yield of both cultivars. The elevated salt stress imposed a negative impact on Rociera’s fruits carbohydrates, organic acids, and anthocyanins, while the antioxidant capacity increased. However, Rociera exhibited high total yield/plant and total yield even under elevated salt stress compared to Camarosa. Camarosa plants grown under high salt levels presented low salinity tolerance index, plant water content, and growth parameters. The fruits exhibited low fresh weight but high sweetness index and antioxidant power. An accumulation of soluble sugars under saline conditions, especially sucrose, was also detected in cv. Camarosa fruits when compared to Rociera. Therefore, the two cvs. exhibited a different pattern of response to salinity stress concerning their physiological, biochemical and nutritional characteristics; however, either could be an interesting alternative for cultivation in areas where a slight salinization of the water or soil imposes a limitation on the rather salt-sensitive crops. Agronomic and biochemical evaluation of salinity stress coupled with monitoring of greenhouse microclimatic conditions will lead to a better understanding of the effects on plant growth and quality characteristics, enhancing the productivity of strawberry cultivars, especially under salt-affected environments. Full article

(This article belongs to the Special Issue Toward a "Green Revolution" for Crop Breeding)

► Show Figures

Figure 1

13 pages, 2224 KiB

Open AccessEditor’s ChoiceArticle

Genotype Selection, and Seed Uniformity and Multiplication to Ensure Common Bean (Phaseolus vulgaris L.) var. Liborino

by Diana Peláez, Paula A. Aguilar, Mariana Mercado, Felipe López-Hernández, Manuel Guzmán, Esteban Burbano-Erazo, Kate Denning-James, Clara I. Medina, Matthew W. Blair, José J. De Vega and Andrés J. Cortés

Agronomy 2022, 12(10), 2285; https://doi.org/10.3390/agronomy12102285 - 23 Sep 2022

Cited by 8 | Viewed by 2121

Abstract

Seed uniformity and stability testing, and multiplication, are key steps in the seed supply chain of the common bean (Phaseolus vulgaris L.) and other crops. Optimizing agronomical practices in these phases can ultimately ensure seed quality and availability, and germplasm prospective utilization. [...] Read more.

Seed uniformity and stability testing, and multiplication, are key steps in the seed supply chain of the common bean (Phaseolus vulgaris L.) and other crops. Optimizing agronomical practices in these phases can ultimately ensure seed quality and availability, and germplasm prospective utilization. However, farmers have rarely standardized seed testing and propagation protocols in local common bean landraces conserved in situ. An example of this is the Liborino variety (var.), a promising yellow Andean common bean known for its presumably high digestibility and adaptation to the local conditions of the Cauca river canyon (northwest Andes of Colombia), but likely experiencing genetic erosion after decades of suboptimal propagation. Therefore, this work intended to evaluate and select locally adapted genotypes of common bean var. Liborino for commercial use, to be later multiplied, evaluated by participatory breeding, and eventually shared with farmers. Specifically, we evaluated 44 accessions of var. Liborino common bean in six adaption and yield field trials in the Cauca river canyon at 1100 and 1400 m a.s.l, and in AGROSAVIA’s “La Selva” research station at 2100 m a.s.l. In parallel, we carried out standardized seed multiplication of a Liborino genotype using best practices to guarantee uniformity and stability. From the 44 accessions, nine were well adapted to the tested local conditions. Four of these accessions exhibited a bush type growth habit, while the remaining five were climbers. The trials revealed maximum average extrapolated yields of up to 1169.4 ± 228.4 kg ha⁻¹ for the bush types (G8152) and up to 1720.0 ± 588.4 kg ha⁻¹ for the climbers (G51018), both at 2100 m a.s.l. Three climbing accessions matched farmers’ expectations for seed coat color and shape, according to a participatory selection exercise. Uniform and stable seed of the selected genotype was delivered in 2022 to 39 farmers, ~6.5 kg of seeds per farmer. Our results will allow implementing bean genetic improvement pipelines, promoting var. Liborino commercialization, and boosting the economic and sustainable development of the rural communities in the Cauca river canyon. Seed uniformity testing and multiplication pipelines must be extended to other bean landraces conserved in situ. Full article

(This article belongs to the Special Issue Legumes Cultivars and Their Genetic Improvements)

► Show Figures

Figure 1

18 pages, 2228 KiB

Open AccessEditor’s ChoiceReview

An Overview on Traditional vs. Green Technology of Extraction Methods for Producing High Quality Walnut Oil

by Lubna Masoodi, Amir Gull, Farooq Ahmad Masoodi, Adil Gani, Jasia Nissar, Tehmeena Ahad, Gulzar Ahmad Nayik, Shaikh Ayaz Mukarram, Béla Kovács, József Prokisch, Hassan El-Ramady and Svein Øivind Solberg

Agronomy 2022, 12(10), 2258; https://doi.org/10.3390/agronomy12102258 - 21 Sep 2022

Cited by 10 | Viewed by 5483

Abstract

Walnut oil is extremely nutrient dense. It has plenty of oil and is high in fatty acids, which have positive biological properties and have a favorable impact on blood lipids and lipoproteins. Walnut oil is low in saturated fatty acids and high in [...] Read more.

Walnut oil is extremely nutrient dense. It has plenty of oil and is high in fatty acids, which have positive biological properties and have a favorable impact on blood lipids and lipoproteins. Walnut oil is low in saturated fatty acids and high in unsaturated fatty acids as well as being high in other vital nutrients. Walnut oil can be extracted using traditional as well as new and green technologies. It is low in saturated fatty acids and high in unsaturated fatty acids (monounsaturated and polyunsaturated fatty acids) as well as being high in other vital nutrients (e.g., selenium, phosphorus, and zinc). Walnut oil can be extracted using traditional as well as new and green technologies. The chosen extraction method has a significant impact on the lipids and other important components extracted. It is critical to select a suitable extraction process for the compounds of interest. In this study, different extraction methods are reviewed, demonstrating the significant benefits of new methods over previous approaches. New green technologies are ecologically benign and allow for shorter extraction times and yields that are comparable to those obtained using traditional methods. The new green technologies allow for higher-quality oils that are less vulnerable to oxidation processes than most of the old technologies. Full article

(This article belongs to the Special Issue Integrated Management of Crop Residues and Their Bioactive Properties in Agri-Food Production)

► Show Figures

Figure 1

14 pages, 882 KiB

Open AccessEditor’s ChoiceArticle

Evaluation of One-Time Applications of Foliar Applied Auxin Co-Applied with Surfactant for Use in Commercial Cutting Propagation

by Anthony T. Bowden, Patricia R. Knight, Jenny B. Ryals, Christine E. H. Coker, Scott A. Langlois, Shaun R. Broderick, Eugene K. Blythe, Hamidou F. Sakhanokho and Ebrahiem M. Babiker

Agronomy 2022, 12(10), 2243; https://doi.org/10.3390/agronomy12102243 - 20 Sep 2022

Cited by 3 | Viewed by 1726

Abstract

Use of foliar auxin applications are increasing in the nursery and greenhouse industry. However, previous research has shown that insufficient auxin is absorbed or translocated to the site of action when foliar auxin applications are used. It is theorized that adding surfactants to [...] Read more.

Use of foliar auxin applications are increasing in the nursery and greenhouse industry. However, previous research has shown that insufficient auxin is absorbed or translocated to the site of action when foliar auxin applications are used. It is theorized that adding surfactants to foliar applications of auxin may help with the absorption and translocation of auxin to the site of action. Research was conducted to determine whether adding surfactants to one-time foliar applications of indole-3-butyric acid (IBA) would be as effective as the current industry standard, the basal quick-dip. Terminal, semi-hardwood cuttings of Red Cascade™ miniature climbing rose (Rosa ‘MOORcap’), common camellia (Camellia japonica) and ‘Southern Charm’ magnolia (Magnolia grandiflora ‘Southern Charm’) were sprayed to the drip point using Hortus IBA Water Soluble Salts™ at concentrations of 0 ppm, 50 ppm, 75 ppm, or 100 ppm for rose cuttings or 0 ppm, 500 ppm, 1000 ppm, or 1500 ppm IBA for camellia or magnolia. To serve as an industry control, the basal end of cuttings was immersed for 3-s in a solution of either 250 ppm, 4000 ppm or 2500 ppm for rose, camellia, or magnolia, respectively. A foliar application of 1500 ppm after sticking was as effective as the basal quick-dip for cuttings of ‘Southern Charm’, while other spray treatments were less effective. A basal quick-dip was more effective than a foliar spray for rooting cuttings of camellia. Auxin rate had no impact on rooting of Red Cascade^™ miniature rose. The goal of commercial plant propagation is to produce high-quality rooted cuttings as quickly as possible. Plant propagation places a large demand on labor within the nursery industry, with one recent report being that labor accounts for >50% of a nursery’s budget. Our results from this trial affirm the results reported by similar trials into foliar applications of auxin suggests that the benefits of foliar applications are species dependent Further work is warranted on examining other auxin and surfactant formulations. Full article

(This article belongs to the Collection Propagation and Conservation of Horticultural Plants: In Vitro and In Vivo)

► Show Figures

Figure 1

16 pages, 3340 KiB

Open AccessEditor’s ChoiceArticle

Monitoring Growth Status of Winter Oilseed Rape by NDVI and NDYI Derived from UAV-Based Red–Green–Blue Imagery

by Nazanin Zamani-Noor and Dominik Feistkorn

Agronomy 2022, 12(9), 2212; https://doi.org/10.3390/agronomy12092212 - 16 Sep 2022

Cited by 7 | Viewed by 2369

Abstract

The current study aimed to evaluate the potential of the normalized difference vegetation index (NDVI), and the normalized difference yellowness index (NDYI) derived from red–green–blue (RGB) imaging to monitor the growth status of winter oilseed rape from seeding to the ripening stage. Subsequently, [...] Read more.

The current study aimed to evaluate the potential of the normalized difference vegetation index (NDVI), and the normalized difference yellowness index (NDYI) derived from red–green–blue (RGB) imaging to monitor the growth status of winter oilseed rape from seeding to the ripening stage. Subsequently, collected values were used to evaluate their correlations with the yield of oilseed rape. Field trials with three seed densities and three nitrogen rates were conducted for two years in Salzdahlum, Germany. The images were rapidly taken by an unmanned aerial vehicle carrying a Micasense Altum multi-spectral camera at 25 m altitudes. The NDVI and NDYI values for each plot were calculated from the reflectance at RGB and near-infrared (NIR) bands’ wavelengths pictured in a reconstructed and segmented ortho-mosaic. The findings support the potential of phenotyping data derived from NDVI and NDYI time series for precise oilseed rape phenological monitoring with all growth stages, such as the seedling stage and crop growth before winter, the formation of side shoots and stem elongation after winter, the flowering stage, maturity, ripening, and senescence stages according to the crop calendar. However, in comparing the correlation results between NDVI and NDYI with the final yield, the NDVI values turn out to be more reliable than the NDYI for the real-time remote sensing monitoring of winter oilseed rape growth in the whole season in the study area. In contrast, the correlation between NDYI and the yield revealed that the NDYI value is more suitable for monitoring oilseed rape genotypes during flowering stages. Full article

(This article belongs to the Section Precision and Digital Agriculture)

► Show Figures

Figure 1

19 pages, 1820 KiB

Open AccessEditor’s ChoiceReview

The Roles of Arbuscular Mycorrhizal Fungi in Influencing Plant Nutrients, Photosynthesis, and Metabolites of Cereal Crops—A Review

by Yaseen Khan, Sulaiman Shah and Tian Hui

Agronomy 2022, 12(9), 2191; https://doi.org/10.3390/agronomy12092191 - 15 Sep 2022

Cited by 19 | Viewed by 5371

Abstract

Arbuscular mycorrhizal (AM) fungi are one of the important microbiota involved in a relationship with plant roots in which the plants and fungi both share and exchange nutrients and shelter. Cereal crops are the most essential sources of carbohydrates, dietary protein, and vitamin [...] Read more.

Arbuscular mycorrhizal (AM) fungi are one of the important microbiota involved in a relationship with plant roots in which the plants and fungi both share and exchange nutrients and shelter. Cereal crops are the most essential sources of carbohydrates, dietary protein, and vitamin B for humans, and they supply the most fundamental diets. AM fungi are introduced as the optimal approach for real agricultural systems for increasing growth and productivity. According to a study from the previous decade, AM fungi were shown to promote crop growth and production, particularly in cereal crops. The AM fungi symbiosis provides a pleasant environment for microorganisms in the root and soil system, which promotes plant nutrition and water availability. AM fungi increase nutrient uptake and assimilation and also increase photosynthetic activity, which is directly associated with plant growth. Furthermore, AM fungi increase the primary and secondary metabolites, as well as soluble proteins and carbohydrates, in cereals crops. AM fungi have been shown to improve plant biomass, yield, and productivity in cereal crops. Additionally, the use of AM fungi enhances plants’ stress tolerance against various environmental stresses. In this review, we integrate the recent findings regarding the effects of AM fungi application on soil, root systems, nutrient availability and uptake, photosynthesis, metabolites, plant growth, and productivity. Furthermore, a large number of studies have been reviewed, and several limitations and research gaps have been identified that must be addressed in future studies. Full article

(This article belongs to the Special Issue Effects of Arbuscular Mycorrhizal(AM) Fungi on Crop and Its Mechanism)

► Show Figures

Figure 1

15 pages, 998 KiB

Open AccessEditor’s ChoiceArticle

The Effects of Agricultural Socialized Services on Sustainable Agricultural Practice Adoption among Smallholder Farmers in China

by Meili Huan, Yajuan Li, Liang Chi and Shaoguo Zhan

Agronomy 2022, 12(9), 2198; https://doi.org/10.3390/agronomy12092198 - 15 Sep 2022

Cited by 14 | Viewed by 2164

Abstract

In recent years, a growing body of literature has explored the determinants and impacts of sustainable agricultural technologies. However, little is known about the relationship between agricultural socialized services that have reshaped the smallholder agricultural system and promoted scale operation in rural China [...] Read more.

In recent years, a growing body of literature has explored the determinants and impacts of sustainable agricultural technologies. However, little is known about the relationship between agricultural socialized services that have reshaped the smallholder agricultural system and promoted scale operation in rural China and environmentally friendly agricultural innovation adoption of the farm. Our study examines the effects of agricultural socialized services on the adoption of sustainable agricultural practices (SAPs). In this study, we capture the number of SAPs adopted, unlike most existing studies that analyze the dichotomous decision of agricultural technology adoption. We apply an endogenous-treatment Poisson regression model to analyze using a national representative farm-level survey data set with 1357 farm households from 132 villages in China. The results show that socialized service use has a significantly positive effect on the number of SAPs adopted. Our results suggest that agricultural socialized services can promote the adoption of sustainable agricultural technologies among smallholders, and thus help transform conventional agriculture into sustainable agriculture. Full article

(This article belongs to the Special Issue Economy and Sociology in Sustainable Agriculture)

► Show Figures

Figure 1

12 pages, 26420 KiB

Open AccessEditor’s ChoiceArticle

Effects of Bacillus amyloliquefaciens QST713 on Photosynthesis and Antioxidant Characteristics of Alfalfa (Medicago sativa L.) under Drought Stress

by Lingjuan Han, Miaoling Zhang, Lixia Du, Li Zhang and Bin Li

Agronomy 2022, 12(9), 2177; https://doi.org/10.3390/agronomy12092177 - 14 Sep 2022

Cited by 14 | Viewed by 1891

Abstract

Drought stress is a prevalent abiotic stress that adversely affects multiple physiological processes in plants, especially their photosynthetic capacity. Application of plant growth–promoting rhizobacteria (PGPR) has been considered as an eco-friendly strategy to ameliorate the deleterious effects of drought stress on plants. The [...] Read more.

Drought stress is a prevalent abiotic stress that adversely affects multiple physiological processes in plants, especially their photosynthetic capacity. Application of plant growth–promoting rhizobacteria (PGPR) has been considered as an eco-friendly strategy to ameliorate the deleterious effects of drought stress on plants. The present study was carried out to investigate the effects of Bacillus amyloliquefaciens QST713 on plant growth, leaf relative water content (RWC), photosynthesis processes, photosynthetic pigment content and antioxidant enzyme activities in two alfalfa varieties, Galalxie Max (drought-tolerant) and Saidi 7 (drought-sensitive) under drought conditions. The results showed that drought stress significantly declined plant biomass production, RWC, photosynthetic pigment content (Chl a, Chl b and carotenoids) and photosynthetic gas exchange parameters (transpiration rate (Tr), stomatal conductance (Gs) and intercellular CO₂ concentration (Ci)), whereas it enhanced the enzymatic activity of peroxidase (POD), catalase (CAT) and ascorbate peroxidase (APX) in both cultivars. In contrast, the inoculation of the bacillus strain QST713 was more effective on plant growth, showing higher plant biomass production compared to the non-inoculated plants under drought stress. Moreover, the application of QST713 significantly promoted the content of RWC, the accumulation of chlorophyll content and the activities of antioxidant enzymes as well as enhanced the photosynthetic capacity of alfalfa seedlings under drought stress. These results suggest that QST713 could be considered as a promising bio-inoculant for plants exposed to environmental stresses. Full article

► Show Figures

Figure 1

26 pages, 4469 KiB

Open AccessEditor’s ChoiceArticle

Effect of a Biostimulant Based on Polyphenols and Glycine Betaine on Tomato Plants’ Responses to Salt Stress

by Javier Zuzunaga-Rosas, Sara González-Orenga, Ana Maria Tofei, Monica Boscaiu, Héctor Moreno-Ramón, Sara Ibáñez-Asensio and Oscar Vicente

Agronomy 2022, 12(9), 2142; https://doi.org/10.3390/agronomy12092142 - 09 Sep 2022

Cited by 14 | Viewed by 3162

Abstract

Climate change accentuates abiotic stress conditions putting at risk several commercial cultivars particularly vulnerable to salinity in the early stages of development, which makes adopting new technologies in tune with the environment necessary to mitigate its impact. In this study, we tested the [...] Read more.

Climate change accentuates abiotic stress conditions putting at risk several commercial cultivars particularly vulnerable to salinity in the early stages of development, which makes adopting new technologies in tune with the environment necessary to mitigate its impact. In this study, we tested the possible effects of a commercial biostimulant (BALOX^®) on enhancing salt stress tolerance in salt-treated tomato plants, analysing plant growth and several stress biochemical markers: photosynthetic pigments, ion contents in roots and leaves, leaf concentrations of different osmolytes, oxidative stress markers, non-enzymatic antioxidants, and the specific activities of major antioxidant enzymes. The experimental design consisted of three soil salinity levels (non-saline, saline, and very saline), two biostimulant doses (0.4 mL and 0.8 mL of the BALOX^® stock per litre of irrigation water), and the non-treated control (without biostimulant), evaluated at 30 and 60 days of treatment. The biostimulant favoured plant growth, especially at the root level and in saline soils. In addition, it helped reduce Na⁺ and Cl⁻ uptake by the roots and seemed to stimulate, to some extent, K⁺ and Ca²⁺ transport to the aerial part of the plant. The BALOX^® application significantly reduced the level of stress affecting the plants in saline soils, as shown by the decrease in the contents of proline and oxidative stress biomarkers and the activity of salt-induced antioxidant enzymes. Some of the biostimulant effects were also observed under low salinity conditions; therefore, in addition to enhancing salt stress responses, BALOX^® appears to stimulate the growth of tomato plants through a general improvement of photosynthesis and primary metabolism. Full article

► Show Figures

Figure 1

14 pages, 1844 KiB

Open AccessEditor’s ChoiceReview

The Increase in the Karstification–Photosynthesis Coupled Carbon Sink and Its Implication for Carbon Neutrality

by Yanyou Wu and Yansheng Wu

Agronomy 2022, 12(9), 2147; https://doi.org/10.3390/agronomy12092147 - 09 Sep 2022

Cited by 11 | Viewed by 2379

Abstract

Two of the most important CO₂ sequestration processes on Earth are plant photosynthesis and rock chemical dissolution. Photosynthesis is undoubtedly the most important biochemical reaction and carbon sink processes on Earth. Karst geological action does not produce net carbon sinks. Photosynthesis and [...] Read more.

Two of the most important CO₂ sequestration processes on Earth are plant photosynthesis and rock chemical dissolution. Photosynthesis is undoubtedly the most important biochemical reaction and carbon sink processes on Earth. Karst geological action does not produce net carbon sinks. Photosynthesis and karstification in nature are coupled. Karstification–photosynthesis coupling can stabilize and increase the capacity of karstic and photosynthetic carbon sinks. Bidirectional isotope tracer culture technology can quantify the utilization of different inorganic carbon sources by plants. Bicarbonate utilization by plants is a driver of karstification–photosynthesis coupling, which depends on plant species and the environment. Carbonic anhydrase, as a pivot of karstification–photosynthesis coupling, can promote inorganic carbon assimilation in plants and the dissolution of carbonate rocks. Karst-adaptable plants can efficiently promote root-derived bicarbonate and atmospheric carbon dioxide use by plants, finally achieving the conjugate promotion of karstic carbon sinks and photosynthetic carbon sinks. Strengthening karstification–photosynthesis coupling and developing karst-adaptable plants will greatly improve the capacity of carbon sinks in karst ecosystems and better serve the “Carbon peak and Carbon neutralization” goals of China. Full article

(This article belongs to the Special Issue Emerging Research on Adaptive Plants in Karst Ecosystems)

► Show Figures

Figure 1

18 pages, 3054 KiB

Open AccessEditor’s ChoiceArticle

Understanding the Role of Physiological and Agronomical Traits during Drought Recovery as a Determinant of Differential Drought Stress Tolerance in Barley

by Md. Hasanuzzaman, Lana Shabala, Timothy J. Brodribb, Meixue Zhou and Sergey Shabala

Agronomy 2022, 12(9), 2136; https://doi.org/10.3390/agronomy12092136 - 08 Sep 2022

Cited by 2 | Viewed by 1818

Abstract

The fast and efficient recovery could be an important trait defining the efficacy of plant drought adaptation. In this work, we aimed to develop a set of simple and appropriate physiological proxies that could be used as reliable indicators to predict plant drought [...] Read more.

The fast and efficient recovery could be an important trait defining the efficacy of plant drought adaptation. In this work, we aimed to develop a set of simple and appropriate physiological proxies that could be used as reliable indicators to predict plant drought responses and validate the role of specific physiological traits such as root length, stomata density, and residual transpiration, in the drought tolerance and recovery in barley. Eighty barley (Hordeum vulgare L.) genotypes were subjected to progressive droughting until the soil moisture level reached 10%, followed by rewatering. Plants were visually scored at the end of drought period and two weeks after rewatering. SPAD values and chlorophyll fluorescence F_v/F_m ratio were also measured, alongside with stomatal density (SD) and residual transpiration (RT). The same genotypes were germinated in paper rolls treated with 15% (w/v) of polyethylene glycol (PEG) 8000 by quantification of changes in the root growth patterns. Responses to drought stress varied among the genotypes, and drought tolerance and recovery scores were significantly correlated with each other. Changes in SPAD value, F_v/F_m ratio and root length were significantly correlated with the drought tolerance and recovery indices. Both indices correlated strongly with the SD and RT of irrigated plants, although in an unexpected direction. We have also correlated the extent of plants’ drought tolerance to their ability to grow in saline soils (a condition often termed a “physiological drought”) and found a positive association between these two traits. The fact that drought tolerant genotype also possessed higher salinity tolerance implies some common mechanisms conferring both traits. Plants having less SD and more RT under irrigated conditions showed higher drought tolerance. It is concluded that lower SD and higher RT under optimal conditions may be used as proxies for drought tolerance in barley. Full article

(This article belongs to the Collection Crop Breeding for Stress Tolerance)

► Show Figures

Figure 1

15 pages, 2807 KiB

Open AccessEditor’s ChoiceArticle

Prediction of the Effect of Nutrients on Plant Parameters of Rice by Artificial Neural Network

by Tanmoy Shankar, Ganesh Chandra Malik, Mahua Banerjee, Sudarshan Dutta, Subhashisa Praharaj, Sagar Lalichetti, Sahasransu Mohanty, Dipankar Bhattacharyay, Sagar Maitra, Ahmed Gaber, Ashok K. Das, Ayushi Sharma and Akbar Hossain

Agronomy 2022, 12(9), 2123; https://doi.org/10.3390/agronomy12092123 - 07 Sep 2022

Cited by 12 | Viewed by 2122

Abstract

Rice holds key importance in food and nutritional security across the globe. Nutrient management involving rice has been a matter of interest for a long time owing to the unique production environment of rice. In this research, an artificial neural network-based prediction model [...] Read more.

Rice holds key importance in food and nutritional security across the globe. Nutrient management involving rice has been a matter of interest for a long time owing to the unique production environment of rice. In this research, an artificial neural network-based prediction model was developed to understand the role of individual nutrients (N, P, K, Zn, and S) on different plant parameters (plant height, tiller number, dry matter production, leaf area index, grain yield, and straw yield) of rice. A feed-forward neural network with back-propagation training was developed using the neural network (nnet) toolbox available in Matlab. For the training of the model, data obtained from two consecutive crop seasons over two years (a total of four crops of rice) were used. Nutrients interact with each other, and the resulting effect is an outcome of such interaction; hence, understanding the role of individual nutrients under field conditions becomes difficult. In the present study, an attempt was made to understand the role of individual nutrients in achieving crop growth and yield using an artificial neural network-based prediction model. The model predicts that growth parameters such as plant height, tiller number, and leaf area index often achieve their maximum performance at below the maximum applied dose, while the maximum yield in most cases is achieved at 100% N, P, K, Zn, and S dose. In addition, the present study attempted to understand the impact of individual nutrients on both plant growth and yield in order to optimize nutrient recommendation and nutrient management, thereby minimizing environmental pollution and wastage of nutrients. Full article

(This article belongs to the Special Issue The New Agricultural Revolution: From Traditional Farms to Smart Agriculture—New Technologies in Agriculture 5.0)

► Show Figures

Figure 1

17 pages, 1306 KiB

Open AccessEditor’s ChoiceArticle

Enhancing Sustainability in Intensive Dill Cropping: Comparative Effects of Biobased Fertilizers vs. Inorganic Commodities on Greenhouse Gas Emissions, Crop Yield, and Soil Properties

by Encarnación Martínez-Sabater, María Dolores Pérez-Murcia, Francisco Javier Andreu-Rodríguez, Luciano Orden, Enrique Agulló, José Sáez-Tovar, Juan Martínez-Tome, María Ángeles Bustamante and Raul Moral

Agronomy 2022, 12(9), 2124; https://doi.org/10.3390/agronomy12092124 - 07 Sep 2022

Cited by 2 | Viewed by 1733

Abstract

The treatment and valorization of organic solid waste has become a promising alternative to increase intensive crop productivity while reducing its environmental impact. Currently, reusing improved organic waste as novel biofertilizers is a vital tool to adapt semiarid agricultural regions to climate change, [...] Read more.

The treatment and valorization of organic solid waste has become a promising alternative to increase intensive crop productivity while reducing its environmental impact. Currently, reusing improved organic waste as novel biofertilizers is a vital tool to adapt semiarid agricultural regions to climate change, but this has been scarcely studied in aromatic crops. The present study aims to assess the greenhouse gas emissions, soil properties, and crop yield of a dill crop using a drip irrigation system with a normalized N application rate of 160 kg N ha⁻¹. We compare eight different fertilizing scenarios grouped into organic-based (manures and compost) and inorganic-based inputs (NPK commodities and slow-release formulations). GHG fluxes were measured during the 57-day fertigation period using static chambers. Key soil properties were measured previous to fertilizer applications and at harvest, coinciding with crop yield estimations. An increase in soil organic carbon was observed with stabilized organic treatments at 0–20 cm soil depth. The results show that stabilized organic-based materials lowered NO₃⁻ concentrations in dill biomass more than synthetic fertilizers, producing similar yields to those with synthetic fertilizers. In general, N₂O emissions were positively affected by the treatments. Local specific emission factors for N₂O were determined (0.08%), which were substantially lower than the default value (0.51%) of IPCC. The cumulative CO₂ emissions were high in all the organic scenarios compared to the control treatment (277 kg C-CO₂ ha⁻¹), probably due to differences in labile organic C contents. Organic-based treatments showed multiple positive effects on crop quality, crop yields, and GHG mitigation potential. The use of organic amendments is an optimized N fertilizing strategy to promote circular economy and sustainability. Full article

► Show Figures

Figure 1

19 pages, 473 KiB

Open AccessEditor’s ChoiceArticle

Effect of Biochar and Inorganic or Organic Fertilizer Co-Application on Soil Properties, Plant Growth and Nutrient Content in Swiss Chard

by Anna Rita Rivelli and Angela Libutti

Agronomy 2022, 12(9), 2089; https://doi.org/10.3390/agronomy12092089 - 01 Sep 2022

Cited by 13 | Viewed by 3579

Abstract

From the perspective of sustainable agri-food production, farmers need to make the best use of natural resources. Biochar can be a solution to adopt a more sustainable way of farming. Despite its environmental and agronomic advantages, biochar has a low plant nutrient value. [...] Read more.

From the perspective of sustainable agri-food production, farmers need to make the best use of natural resources. Biochar can be a solution to adopt a more sustainable way of farming. Despite its environmental and agronomic advantages, biochar has a low plant nutrient value. This study evaluated the effect of biochar and the co-application of an inorganic or organic fertilizer on the soil properties, growth and nutrient content of Swiss chard (Beta vulgaris L. var. cycla, Caryophyllales order, Chenopodiaceae family). The experiment consisted of two factors: biochar type (from vineyard prunings and wood chips) and fertilizing source (ammonium nitrate and vermicompost). Biochars were applied at a 2% rate (w/w) and fertilizers at a dose providing 280 kg N ha⁻¹. The soil properties (pH, EC, extractable anions, cations, total N, Corg and C/N ratio) were measured before the plants were transplanted and at the end of the growing cycle, along with the growth parameters (leaf number, length and fresh weight) of each leaf cut, the productive parameters (total number of leaves and yield per plant) at the end of the growing cycle and the leaf content of anions (NO₃⁻, P₂O₄³⁻, SO₄²⁻), cations (NH₄⁺, Na⁺, K⁺, Ca²⁺, Mg²⁺) and total N. The co-application of biochar and a fertilizing source had a positive effect on soil properties and leaf nutrient content. Vermicompost increased plant growth by 22% and plant yield by 116%, in contrast to biochar, and increased limited leaf NO₃⁻ accumulation by about 81% in comparison to ammonium nitrate. The co-application of biochar and vermicompost is the better option to increase Swiss chard yield while preserving the nutritional and health qualities of the product. Full article

(This article belongs to the Topic Innovation and Solution for Sustainable Agriculture)

► Show Figures

Figure 1

20 pages, 1777 KiB

Open AccessEditor’s ChoiceArticle

Policy Gaps Related to Sustainability in Hungarian Agribusiness Development

by Edit Hoyk, Ádám Szalai, András Palkovics and Jenő Zsolt Farkas

Agronomy 2022, 12(9), 2084; https://doi.org/10.3390/agronomy12092084 - 01 Sep 2022

Cited by 8 | Viewed by 2481

Abstract

The world’s agriculture faces many challenges nowadays, such as tackling the effects of climate change, conserving agrobiodiversity, or feeding the Earth’s growing population. These issues often induce conflicting development directions, such as digitalization and ecologization, as the case of the European Union’s Common [...] Read more.

The world’s agriculture faces many challenges nowadays, such as tackling the effects of climate change, conserving agrobiodiversity, or feeding the Earth’s growing population. These issues often induce conflicting development directions, such as digitalization and ecologization, as the case of the European Union’s Common Agricultural Policy (CAP) shows. In the last decades, policymakers have focused mainly on greening agricultural production and the food industry, and now the CAP is part of the European Green Deal. In our research, we assessed the sustainability problems affecting the agribusiness sector and food consumption in Hungary using descriptive statistical analysis. On the other hand, we examined the latest sectoral development documents (Digital Agricultural Strategy, Digital Food Industry Strategy) in order to find out to what extent they answer the identified issues. Our results revealed that the Hungarian agribusiness sector is struggling with several sustainability challenges, which do not receive adequate attention from policymakers. The newest development strategies are characterized by forced digitalization efforts, while their applicability and effectiveness are uncertain. Because of similar development trajectories, we believe most of our results are relevant to other Central Eastern European Member states. Hence, further CAP and national policy reforms are needed to make Europe’s agribusiness sector more sustainable. Full article

(This article belongs to the Section Farming Sustainability)

► Show Figures

Figure 1

28 pages, 5678 KiB

Open AccessEditor’s ChoiceArticle

Applying Spatial Statistical Analysis to Ordinal Data for Soybean Iron Deficiency Chlorosis

by Zhanyou Xu, Steven B. Cannon and William D. Beavis

Agronomy 2022, 12(9), 2095; https://doi.org/10.3390/agronomy12092095 - 01 Sep 2022

Cited by 2 | Viewed by 1647

Abstract

Accounting for field variation patterns plays a crucial role in interpreting phenotype data and, thus, in plant breeding. Several spatial models have been developed to account for field variation. Spatial analyses show that spatial models can successfully increase the quality of phenotype measurements [...] Read more.

Accounting for field variation patterns plays a crucial role in interpreting phenotype data and, thus, in plant breeding. Several spatial models have been developed to account for field variation. Spatial analyses show that spatial models can successfully increase the quality of phenotype measurements and subsequent selection accuracy for continuous data types such as grain yield and plant height. The phenotypic data for stress traits are usually recorded in ordinal data scores but are traditionally treated as numerical values with normal distribution, such as iron deficiency chlorosis (IDC). The effectiveness of spatial adjustment for ordinal data has not been systematically compared. The research objective described here is to evaluate methods for spatial adjustment of ordinal data, using soybean IDC as an example. Comparisons of adjustment effectiveness for spatial autocorrelation were conducted among eight different models. The models were divided into three groups: Group I, moving average grid adjustment; group II, geospatial autoregressive regression (SAR) models; and Group III, tensor product penalized P-splines. Results from the model comparison show that the effectiveness of the models depends on the severity of field variation, the irregularity of the variation pattern, and the model used. The geospatial SAR models outperform the other models for ordinal IDC data. Prediction accuracy for the lines planted in the IDC high-pressure area is 11.9% higher than those planted in low-IDC-pressure regions. The relative efficiency of the mixed SAR model is 175%, relative to the baseline ordinary least squares model. Even though the geospatial SAR model is the best among all the compared models, the efficiency is not as good for ordinal data types as for numeric data. Full article

(This article belongs to the Special Issue Predictions and Estimations in Agricultural Production under a Changing Climate)

► Show Figures

Figure 1

18 pages, 479 KiB

Open AccessEditor’s ChoiceCommunication

Effect of Clover Sward Management on Nitrogen Fixation and Performance of Following Spring- and Winter Wheat Crops; Results of a 3-Year Pilot Study

by Andrew Wilkinson, John N. Wilkinson, Peter Shotton, Mick Eyre, Gultakin Hasanaliyeva, Paul Bilsborrow, Carlo Leifert and Leonidas Rempelos

Agronomy 2022, 12(9), 2085; https://doi.org/10.3390/agronomy12092085 - 01 Sep 2022

Cited by 5 | Viewed by 1475

Abstract

Wheat yields in organic production are significantly lower than those achieved in conventional farming systems and in Northern Europe organic farmers also struggle to achieve the processing quality levels demanded by millers and bakers, especially in winter-wheat crops. Here, we report the findings [...] Read more.

Wheat yields in organic production are significantly lower than those achieved in conventional farming systems and in Northern Europe organic farmers also struggle to achieve the processing quality levels demanded by millers and bakers, especially in winter-wheat crops. Here, we report the findings of a 3-year pilot study which investigated the potential of increasing grain yields and both standard processing (e.g., grain protein levels and specific weights) and selected nutritional (tocopherol and tocotrienol isomers) quality parameters via (i) changes in the management of clover crops grown before wheat (Rhizobium seed inoculation, application of greenwaste compost to clover swards) and (ii) use of new varieties developed in both the UK and continental Europe. Results indicate that the use of compost amendment to preceding clover swards significantly increased the grain protein levels in the three winter-wheat, but not the four spring-wheat varieties, and also significantly increases grain yields in one winter-wheat variety (Greina). In contrast, the use of Rhizobium-inoculation was found to significantly reduce protein concentrations in the winter-, but not spring wheat varieties, and had no significant effect on grain yields in both winter and spring wheat. However, analysis of variance detected significant interactions between Rhizobium seed inocula in clover pre-crops and (a) compost application for grain specific weights in winter-wheat and grain hardness in spring wheat crops and (b) variety for grain protein content in spring wheat crops. No significant effect of clover pre-crop management on tocopherol and tocotrienol isomer profiles could be detected, although significant differences between varieties were detected in both winter and spring wheat. Results of this pilot study need to be confirmed in future trials, but indicate that both (a) changes in clover-management practices and (b) the selections of wheat varieties that are more suitable for organic farming systems has the potential to increase grain yield and allow organic farmers to more frequently achieve baking or milling grade quality. Full article

(This article belongs to the Special Issue Integrated Soil, Crop and Human Nutrition and Health Management in Organic Agriculture)

► Show Figures

Figure 1

14 pages, 1175 KiB

Open AccessEditor’s ChoiceArticle

Synergistic Effect of Plant-Growth-Promoting Rhizobacteria Improves Strawberry Growth and Flowering with Soil Salinization and Increased Atmospheric CO₂ Levels and Temperature Conditions

by Susana Redondo-Gómez, Jesús V. García-López, Jennifer Mesa-Marín, Eloísa Pajuelo, Ignacio D. Rodriguez-Llorente and Enrique Mateos-Naranjo

Agronomy 2022, 12(9), 2082; https://doi.org/10.3390/agronomy12092082 - 31 Aug 2022

Cited by 14 | Viewed by 2299

Abstract

Biofertilization with plant-growth-promoting rhizobacteria (PGPR) can positively affect the growth and health of host plants and reinforce their tolerance of stressors. Here, we investigate the use of isolated PGPR consortia from halophytes to improve strawberry growth and flowering performance under saline and elevated [...] Read more.

Biofertilization with plant-growth-promoting rhizobacteria (PGPR) can positively affect the growth and health of host plants and reinforce their tolerance of stressors. Here, we investigate the use of isolated PGPR consortia from halophytes to improve strawberry growth and flowering performance under saline and elevated CO₂ and temperature conditions. Growth, flower bud production, and the photosynthetic apparatus response were determined in strawberry plants grown at 0 and 85 mmol L⁻¹ NaCl and in two atmospheric CO₂-temperature combinations (400/700 ppm and 25/+4 °C, respectively). Biofertilization improved strawberry plant growth and flower bud production, independently of salinity conditions, at ambient CO₂ and 25 °C, while bacterial inoculation only had a positive effect on plant growth in the presence of salt in high CO₂ and at +4 °C. Biofertilizers 1 and 3 generated the largest biomass of strawberries at 400 ppm CO₂ and 0 and 85 mmol L⁻¹ NaCl, respectively, while biofertilizer 1 did so in the presence of salt and in an atmosphere enriched with CO₂ and at +4 °C. The effect of the consortia was mediated by bacterial strain PGP properties, rather than by an improvement in the photosynthetic rate of the plants. Furthermore, biofertilizers 1 and 2 increased the number of flower buds in the absence of salt, while biofertilizers 3 and 4 did so for salt-inoculated plants at 400 ppm CO₂ and at 25 °C. There was no effect of inoculation on flower bud production of plants grown at high CO₂ and at +4 °C. Finally, we concluded that the effect of bacterial inoculation on strawberry growth and flowering depended on the type of bacterial strain and growth conditions. This highlights the importance of developing studies considering stress interaction to assess the real potential of biofertilizers. Full article

(This article belongs to the Special Issue How Could Microorganisms Benefit the Agriculture Environment?)

► Show Figures

Figure 1

33 pages, 2509 KiB

Open AccessEditor’s ChoiceReview

Mechanisms and Strategies of Plant Microbiome Interactions to Mitigate Abiotic Stresses

by Neelma Munir, Maria Hanif, Zainul Abideen, Muhammed Sohail, Ali El-Keblawy, Emanuele Radicetti, Roberto Mancinelli and Ghulam Haider

Agronomy 2022, 12(9), 2069; https://doi.org/10.3390/agronomy12092069 - 30 Aug 2022

Cited by 36 | Viewed by 7258

Abstract

Abiotic stresses are the most significant factors reducing agricultural productivity. Plants face extreme environmental conditions that may affect their biological mechanisms, thereby influencing their growth and development. Microorganisms possess substantial metabolites that aid in helping plants mitigate abiotic stresses. Plants’ interaction with microbes [...] Read more.

Abiotic stresses are the most significant factors reducing agricultural productivity. Plants face extreme environmental conditions that may affect their biological mechanisms, thereby influencing their growth and development. Microorganisms possess substantial metabolites that aid in helping plants mitigate abiotic stresses. Plants’ interaction with microbes constitutes a diversified ecosystem, as sometimes both the partners share a mutualistic relationship. Endophytes, plant-growth-promoting rhizobacteria (PGPRs), and arbuscular mycorrhizal fungi (AMFs) are examples of microorganisms that play an essential role in alleviating abiotic stresses and, hence, improving plant growth. The plant–microbe interaction leads to the modulation of complex mechanisms in the plant cellular system. Moreover, the residing microbial flora also inhibits the phytopathogens, therefore, it becomes part of plants’ innate defense system. Keeping in view the growing environmental concerns, it is important to identify the role of the plant microbiome in the transportation of nutrients to maintain sustainable production. Furthermore, it is important to identify the factors enabling plants to recruit beneficial microbial species and how to deal with the potential pathogens. Therefore, this review aims to summarize the impacts of various abiotic stressors on agricultural productivity and the role of beneficial microorganisms in mitigating the negative effects of abiotic stresses. The literature review also shows that the beneficial microbes, including PGPRs, AMFs, and endophytes, adopt various mechanisms for ameliorating the negative effects of various stresses. It has been observed that biochar and microbes, either individually or in combination, can play a significant role in maintaining plant growth under stress conditions. Although conventional inoculation of beneficial microbes mitigates abiotic stresses and enhances productivity, the advancement in genetic engineering would help transfer specific genes from the microbes to plants to aid in abiotic stress mitigation. Full article

(This article belongs to the Topic Innovation and Solution for Sustainable Agriculture)

► Show Figures

Graphical abstract

15 pages, 3479 KiB

Open AccessEditor’s ChoiceArticle

Extreme Weather and Grazing Management Influence Soil Carbon and Compaction

by Anish Subedi, Dorcas Franklin, Miguel Cabrera, Subash Dahal, Dennis Hancock, Amanda McPherson and Lawton Stewart

Agronomy 2022, 12(9), 2073; https://doi.org/10.3390/agronomy12092073 - 30 Aug 2022

Cited by 2 | Viewed by 1460

Abstract

Understanding the influence of cattle grazing on soil carbon and bulk density during extreme dry to wet periods can help us design more resilient and sustainable grazing systems for low-input management scenarios. A study was conducted to evaluate changes in loss-on-ignition (LOI) carbon [...] Read more.

Understanding the influence of cattle grazing on soil carbon and bulk density during extreme dry to wet periods can help us design more resilient and sustainable grazing systems for low-input management scenarios. A study was conducted to evaluate changes in loss-on-ignition (LOI) carbon and bulk density (BD) in the top 20 cm soil layer when eight continuous grazing (CG) pastures were converted to either continuous grazing with hay distribution (CHD-4) or strategic grazing (STR-4). STR included lure management of cattle with movable-equipages, exclusion and over-seeding erosion-vulnerable areas, and a relaxed rotational grazing. Changes in relationships between cattle density (CD), LOI, and BD were evaluated for change in grazing management from 2015 to 2018. Reduction in LOI carbon (0–5, 5–10, 10–20 cm) and BD (5–10 cm) were observed in both CHD and STR pastures in 2018. CD in 2015 had either no relationship or a negative relationship on LOI while in 2018, CD positively influenced LOI in CHD (0–5 cm) and STR (0–5 and 5–10 cm) pastures. STR had lower BD with higher CD further away from concentrated flow paths mirroring cattle movement. Exclusions in the STR pastures had the greatest reduction in BD. Even with reduced carbon in the 0–5 cm soil layer the reduction in BD in the 5–10 cm soil layer helped build resilience in grazing systems that experience extreme weather events such as going from very dry to extensively wet. Full article

(This article belongs to the Special Issue Advance in Grassland Productivity and Sustainability)

► Show Figures

Figure 1

18 pages, 3866 KiB

Open AccessEditor’s ChoiceArticle

SE-YOLOv5x: An Optimized Model Based on Transfer Learning and Visual Attention Mechanism for Identifying and Localizing Weeds and Vegetables

by Jian-Lin Zhang, Wen-Hao Su, He-Yi Zhang and Yankun Peng

Agronomy 2022, 12(9), 2061; https://doi.org/10.3390/agronomy12092061 - 29 Aug 2022

Cited by 21 | Viewed by 2676

Abstract

Weeds in the field affect the normal growth of lettuce crops by competing with them for resources such as water and sunlight. The increasing costs of weed management and limited herbicide choices are threatening the profitability, yield, and quality of lettuce. The application [...] Read more.

Weeds in the field affect the normal growth of lettuce crops by competing with them for resources such as water and sunlight. The increasing costs of weed management and limited herbicide choices are threatening the profitability, yield, and quality of lettuce. The application of intelligent weeding robots is an alternative to control intra-row weeds. The prerequisite for automatic weeding is accurate differentiation and rapid localization of different plants. In this study, a squeeze-and-excitation (SE) network combined with You Only Look Once v5 (SE-YOLOv5x) is proposed for weed-crop classification and lettuce localization in the field. Compared with models including classical support vector machines (SVM), YOLOv5x, single-shot multibox detector (SSD), and faster-RCNN, the SE-YOLOv5x exhibited the highest performance in weed and lettuce plant identifications, with precision, recall, mean average precision (mAP), and F1-score values of 97.6%, 95.6%, 97.1%, and 97.3%, respectively. Based on plant morphological characteristics, the SE-YOLOv5x model detected the location of lettuce stem emerging points in the field with an accuracy of 97.14%. This study demonstrates the capability of SE-YOLOv5x for the classification of lettuce and weeds and the localization of lettuce, which provides theoretical and technical support for automated weed control. Full article

(This article belongs to the Special Issue Computer Vision for Intelligent Crop Identification and Crop Protection)

► Show Figures

Figure 1

21 pages, 3780 KiB

Open AccessEditor’s ChoiceArticle

The Molecular Composition of Humic Acids in Permafrost Peats in the European Arctic as Paleorecord of the Environmental Conditions of the Holocene

by Roman Vasilevich, Evgeny Lodygin and Evgeny Abakumov

Agronomy 2022, 12(9), 2053; https://doi.org/10.3390/agronomy12092053 - 28 Aug 2022

Cited by 8 | Viewed by 1432

Abstract

The purpose of our research is focused on examination of the transformation regularities of molecular composition of humic acids (HAs) in the hummocky frozen peatlands of the European Arctic as a marker of climatic changes in the Holocene, and assessment of the stabilization [...] Read more.

The purpose of our research is focused on examination of the transformation regularities of molecular composition of humic acids (HAs) in the hummocky frozen peatlands of the European Arctic as a marker of climatic changes in the Holocene, and assessment of the stabilization of soil organic matter under the conditions of modern climatic warming. Histosols located in the two subzones of the European Arctic served as the research subjects. This territory is actively used for reindeer breeding, which is a vital agricultural branch in the Far North of the Russian Federation. The data obtained reveal the main trends in the formation of HAs from Arctic peatlands under different environmental conditions. Modern peat sediments (top layers) in the middle and late Holocene period formed out of bryophyte residues and contained HAs with long-chain carbohydrate and paraffin structures in their composition. These structures enlarged the dynamic radii of HA molecules, and, thus, caused high average molecular weight values. The more favorable climatic conditions of the early Holocene (the Atlantic optimum) defined the botanical composition of peat, which was dominated by tree and sedge communities with high contents of lignin components and, as a consequence, a larger share of aromatic fragments, characterized by thermo-biodynamic resistance in HAs of horizons in the lower and central profile parts. The molecules of HAs are an archive of paleoclimatic records. The Subboreal and Subatlantic climatic conditions determined the specifics of vegetation precursors and, as a result, the molecular structure of HAs in seasonally thawed layers, with a predominance of long-chain aliphatic fragments. The conversion of HAs from Histosols led to an increase in the proportion of carbon in branched and short-chain paraffinic structures with their subsequent cyclization and aromatization. The results of this process are most clearly manifested in layers formed during the Holocene I and II climatic optima. Higher biologically active temperatures of the seasonally thawed layer of soils at bare spots (without vegetation) determined the accumulation of thermodynamically more stable HA molecules with a high content of aromatic fragments. This contributed to both the stabilization of the SOM and the conservation of peatlands in general. Full article

(This article belongs to the Topic Frontier Studies in Composition of Humic Substances and Soil Organic Matter)

► Show Figures

Figure 1

15 pages, 959 KiB

Open AccessEditor’s ChoiceReview

Emerging Trends in Allelopathy: A Genetic Perspective for Sustainable Agriculture

by Meriem Miyassa Aci, Rossana Sidari, Fabrizio Araniti and Antonio Lupini

Agronomy 2022, 12(9), 2043; https://doi.org/10.3390/agronomy12092043 - 27 Aug 2022

Cited by 15 | Viewed by 3959

Abstract

Over the past decades, a growing interest in allelopathy has been recorded due to the effective use of allelochemicals as growth regulators, bioherbicides, insecticides, and antimicrobial crop protection in the sustainable agriculture field. So far, the genetic aspects of the allelopathic effects have [...] Read more.

Over the past decades, a growing interest in allelopathy has been recorded due to the effective use of allelochemicals as growth regulators, bioherbicides, insecticides, and antimicrobial crop protection in the sustainable agriculture field. So far, the genetic aspects of the allelopathic effects have been poorly studied, and the identification of allelopathic genes and/or genomic regions (QTLs) has become a challenge to implement specific breeding programs. Here, we review the recent genetic and genome-based research findings in allelopathy, with a particular emphasis on weed control, which is one of the major crop yield-limiting factors. We discuss the key plant–microorganism interactions, including the cross-kingdom RNAi phenomenon and the involvement of microRNAs in allelopathy. Through this review, we wanted to lay the foundation for advancing knowledge in allelopathy and uncover the areas where research is needed. Full article

(This article belongs to the Section Crop Breeding and Genetics)

► Show Figures

Figure 1

Journal Menu

Journal Browser

Editor’s Choice Articles

Further Information

Guidelines

MDPI Initiatives

Follow MDPI