Research

18 pages, 10241 KiB

Open AccessArticle

Effect of Alternate Wetting and Drying on the Emission of Greenhouse Gases from Rice Fields on the Northern Coast of Peru

by Ida Echegaray-Cabrera, Lena Cruz-Villacorta, Lia Ramos-Fernández, Mirko Bonilla-Cordova, Elizabeth Heros-Aguilar and Lisveth Flores del Pino

Agronomy 2024, 14(2), 248; https://doi.org/10.3390/agronomy14020248 - 24 Jan 2024

Cited by 1 | Viewed by 998

Abstract

The cultivation of rice is one of the main sources of greenhouse gas (GHG) emissions due to continuously flooded irrigation (CF), which demands large volumes of water. As an alternative solution, alternate wetting and drying (AWD) irrigation has been developed as a water-saving [...] Read more.

The cultivation of rice is one of the main sources of greenhouse gas (GHG) emissions due to continuously flooded irrigation (CF), which demands large volumes of water. As an alternative solution, alternate wetting and drying (AWD) irrigation has been developed as a water-saving strategy. This study was conducted at the Experimental Agricultural Station (EEA) in Vista, Florida, in the Lambayeque region located on the northern coast of Peru. Thus, it was analyzed the effect of AWD irrigation at different depths (5, 10, and less than 20 cm below the surface) compared to CF control on methane (CH₄) and nitrous oxide (N₂O) emissions and rice grain yield. AWD treatments reduced CH₄ emissions by 84% to 99% but increased N₂O emissions by 66% to 273%. In terms of Global Warming Potential (GWP), the AWD₁₀ treatment demonstrated a 77% reduction and a Water Use Efficiency (WUE) of 0.96, affecting only a 2% decrease in rice grain yield, which ranged between 11.85 and 14.01

{t ha}^{- 1}

. Likewise, this study provides sufficient evidence for the adoption of AWD irrigation as a strategy for the efficient use of water resources and the mitigation of GHG emissions in rice cultivation in the study area, compared to continuous flooded irrigation. Full article

(This article belongs to the Special Issue Water Saving in Irrigated Agriculture)

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17 pages, 3353 KiB

Open AccessArticle

Water–Salt Migration Patterns among Cropland–Wasteland–Fishponds in the River-Loop Irrigation Area

by Cuicui Yu, Haibin Shi, Qingfeng Miao, José Manuel Gonçalves, Yan Yan, Zhiyuan Hu, Cong Hou and Yi Zhao

Agronomy 2024, 14(1), 107; https://doi.org/10.3390/agronomy14010107 - 01 Jan 2024

Viewed by 1018

Abstract

In order to investigate the influence of freshwater fish ponds on water and salt transport in cultivated wasteland in salinized areas, a typical study area was selected in the middle and lower reaches of the Hetao Irrigation District in China in the Yichang [...] Read more.

In order to investigate the influence of freshwater fish ponds on water and salt transport in cultivated wasteland in salinized areas, a typical study area was selected in the middle and lower reaches of the Hetao Irrigation District in China in the Yichang Irrigation Domain, and the temporal and spatial changes in the salinity of soil and salinity of groundwater and fish pond water in the cultivated–wasteland–fish pond system were characterized through the monitoring of the environmental information of soil and groundwater at the boundaries of the cultivated land, wasteland, and fish ponds. Salinity changes and groundwater migration in different periods were determined, and the response of soil salinity to the depth of groundwater burial was analyzed, as well as the effect of fish ponds on soil salinization. The results showed that the amount of groundwater migrating from cropland to wasteland during the simulation period in 2022 was 2700 m³, the amount of groundwater migrating from wasteland to fish ponds was 630 m³, and the amount of groundwater migrating from fish ponds to wasteland during the fall watering period was 440 m³. From an overall perspective, the average soil salinity of wasteland was 1.56 times higher than that of the boundary of fish ponds. Not only do fish ponds play a positive role in the ecosystem, but they also have a desalinization effect that reduces soil salinity significantly. Groundwater depth and soil salinity have an exponential relationship; when the depth of groundwater is greater than 1.75 m, the soil salinity varies little with the depth of groundwater and the soil salinity is less than 0.66 ds/m, which can be determined as the critical depth, and the average depth of groundwater in cultivated land in the study area is 1.5 m. Therefore, it is necessary to reasonably control the water level of fish ponds, so as to make the groundwater depth of cultivated land control between 1.75 m and 2.0 m, and to prevent soil salinization. Full article

(This article belongs to the Special Issue Water Saving in Irrigated Agriculture)

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18 pages, 3441 KiB

Open AccessArticle

Artificial Neural Networks versus Multiple Linear Regressions to Predict the Christiansen Uniformity Coefficient in Sprinkler Irrigation

by Ahmed Skhiri, Karim Gabsi, Ahmed Z. Dewidar and Mohamed A. Mattar

Agronomy 2023, 13(12), 2979; https://doi.org/10.3390/agronomy13122979 - 01 Dec 2023

Viewed by 659

Abstract

The Christiansen Uniformity Coefficient (CUC) describes the distribution of water in a sprinkler system. In this study, two types of models were developed to predict the Christiansen Uniformity Coefficient (CUC) of sprinkler irrigation systems: Artificial Neural Network (ANN), specifically the feed-forward neural networks, [...] Read more.

The Christiansen Uniformity Coefficient (CUC) describes the distribution of water in a sprinkler system. In this study, two types of models were developed to predict the Christiansen Uniformity Coefficient (CUC) of sprinkler irrigation systems: Artificial Neural Network (ANN), specifically the feed-forward neural networks, and multiple linear regression (MLR) models. The models were trained on a dataset of published research on the CUC of sprinkler irrigation systems, which included data on a variety of design, operating, and meteorological condition variables. In order to build the predictive model of CUC, 10 input parameters were used including sprinkler height (H), working pressure (P), nozzle diameter (D and d_a), sprinkler line spacing (S_L), sprinkler spacing (S_S), wind speed (WS), wind direction (WD), temperature (T), and relative humidity (RH). Fifty percent (50%) of the data was used to train ANN models and the remaining data for cross-validation (25%) and for testing (25%). Multiple linear regression models were built using the training data. Four statistical criteria were used to evaluate the model’s predictive quality: the correlation coefficient (R), the index of agreement (d), the root mean square error (RMSE), and the mean absolute error (MAE). Statistical analysis demonstrated that the best predictive ability was obtained when the models (ANN and MLR) utilized all the input variables. The results demonstrated that the accuracy of ANN models, predicting the CUC of sprinkler irrigation systems, is higher than that of the MLR ones. During the training stage, the ANN models were more accurate in predicting CUC than MLR, with higher R (0.999) and d (0.999) values and lower MAE (0.167) and RMSE (0.456) values. The R values of the MLR model fluctuated between 0.226 and 0.960, the d values oscillated from 0.174 to 0.979, the MAE values were in the range of 2.458% and 10.792%, and the RMSE values fluctuated from 2.923% to 13.393%. Furthermore, the study revealed that WS and WD are the most influential climatic parameters. The ANN model can be used to develop more accurate tools for predicting the CUC of sprinkler irrigation systems. This can help farmers to design and operate their irrigation systems more efficiently, which can save them time and money. Full article

(This article belongs to the Special Issue Water Saving in Irrigated Agriculture)

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28 pages, 6088 KiB

Open AccessArticle

Developing a Regional Network for the Assessment of Evapotranspiration

by Alicia Lopez-Guerrero, Arantxa Cabello-Leblic, Elias Fereres, Domitille Vallee, Pasquale Steduto, Ihab Jomaa, Osama Owaneh, Itidel Alaya, Mahmoud Bsharat, Ayman Ibrahim, Kettani Abla, Alaa Mosad, Abdallah Omari, Rim Zitouna-Chebbi and Jose A. Jimenez-Berni

Agronomy 2023, 13(11), 2756; https://doi.org/10.3390/agronomy13112756 - 31 Oct 2023

Viewed by 928

Abstract

Determining evapotranspiration (ET) is essential for water accounting and for the management of irrigated agriculture from farm to region. We describe here a collaborative initiative aimed at establishing a prototype ET network in six countries of North Africa and the Near East (NENA [...] Read more.

Determining evapotranspiration (ET) is essential for water accounting and for the management of irrigated agriculture from farm to region. We describe here a collaborative initiative aimed at establishing a prototype ET network in six countries of North Africa and the Near East (NENA region). The network utilizes a low-cost and open-source system, termed the CORDOVA-ET, consisting of a base station and sensing nodes to collect the weather data needed to determine the reference and actual ET (ET_o and ET_a). Here, we describe the network-deployment processes, system architecture, data-collection methodology, quality-control procedures, and some of the ET results obtained so far during a four-year period, starting in 2018. The network has been developed as an iterative and collaborative process, where training and capacity building have been the main drivers. The feedback and experiences gathered from the users have helped improve the different versions of the prototypes and enhance their assembly, deployment, reliability, and ease of operation. At the same time, the involvement in the construction, maintenance, and data analysis has also provided valuable insight into calculating ET from energy-balance methods. The network operated during six cropping seasons and the results were mixed, while data integrity (hourly and daily) varied from 95 to 23% depending on the country and season. Validation of the ET estimates was performed using the ECMWF ERA5 dataset as an independent reference. The energy-balance algorithm implemented in the system to determine the ET_a was validated using the OpenCropLib Python library. While the results of the data validation demonstrated the reliability and accuracy of the CORDOVA-ET system, network operations required significant support and special motivation on the part of the users. It is concluded that collaboration among users, together with the support services and participation of different stakeholders interested in agricultural water management, would be essential elements to ensure the sustainability of the ET network. Full article

(This article belongs to the Special Issue Water Saving in Irrigated Agriculture)

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12 pages, 2138 KiB

Open AccessArticle

Effect of Irrigation Methods on Black Truffle Production

by Alba Magarzo, Sonia Alba, Luis Santos del Blanco, Iván Franco Manchón, Jaime Olaizola, Pablo Martín Pinto and Olaya Mediavilla

Agronomy 2023, 13(10), 2505; https://doi.org/10.3390/agronomy13102505 - 28 Sep 2023

Viewed by 4061

Abstract

Spain is one of the main producers of black truffle (Tuber melanosporum Vittad.), a fungus of great economic importance. Black truffles are usually cultivated in Quercus ilex orchards, as water availability is one of the most important factors influencing truffle production. Optimizing [...] Read more.

Spain is one of the main producers of black truffle (Tuber melanosporum Vittad.), a fungus of great economic importance. Black truffles are usually cultivated in Quercus ilex orchards, as water availability is one of the most important factors influencing truffle production. Optimizing watering systems is essential to reduce the amount of water wasted. Nevertheless, up to now, no study has been carried out comparing the efficiency of different irrigation systems in truffle plantations. The aim of this study was to compare the efficiency of two different irrigation systems, namely a drip irrigation system and a micro-sprinkler system, in a Quercus ilex plantation situated in Burgos, Spain. Our data showed that there were no differences between the two irrigation systems in terms of truffle yields, the number of truffles, quality (based on truffle size), or the date of truffle harvesting. However, when other parameters were taken into consideration, such as the economic and environmental impact of installing and running these systems, drip irrigation was deemed the superior irrigation system because it uses less water. This study validates for the first time the use of drip irrigation rather than a micro-sprinkler system (the most commonly used in truffle plantations) because of its greater water use efficiency, which is an increasingly important consideration given future climate change scenarios marked by global water scarcity. Full article

(This article belongs to the Special Issue Water Saving in Irrigated Agriculture)

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17 pages, 6395 KiB

Open AccessArticle

Identification of Water Layer Presence in Paddy Fields Using UAV-Based Visible and Thermal Infrared Imagery

by Guangfei Wei, Huifang Chen, En Lin, Xuhua Hu, Hengwang Xie, Yuanlai Cui and Yufeng Luo

Agronomy 2023, 13(7), 1932; https://doi.org/10.3390/agronomy13071932 - 21 Jul 2023

Viewed by 1237

Abstract

The accurate identification of the water layer condition of paddy fields is a prerequisite for precise water management of paddy fields, which is important for the water-saving irrigation of rice. Until now, the study of unmanned aerial vehicle (UAV) remote sensing data to [...] Read more.

The accurate identification of the water layer condition of paddy fields is a prerequisite for precise water management of paddy fields, which is important for the water-saving irrigation of rice. Until now, the study of unmanned aerial vehicle (UAV) remote sensing data to monitor the moisture condition of field crops has mostly focused on dry crops, and research on the water status of paddy fields has been relatively limited. In this study, visible and thermal infrared images of paddy fields at key growth stages were acquired using a UAV remote sensing platform, and three model input variables were constructed by extracting the color features and temperature features of each field, while K-nearest neighbor (KNN), support vector machine (SVM), random forest (RF), and logistic regression (LR) analysis methods were applied to establish a model for identifying the water layer presence in paddy fields. The results showed that KNN, SVM, and RF performed well in recognizing the presence of water layers in paddy fields; KNN had the best recognition accuracy (89.29%) via algorithm comparison and parameter preference. In terms of model input variables, using multisource remote sensing data led to better results than using thermal or visible images alone, and thermal data was more effective than visible data for identifying the water layer status of rice fields. This study provides a new paradigm for monitoring the water status of rice fields, which will be key to the precision irrigation of paddy fields in large regions in the future. Full article

(This article belongs to the Special Issue Water Saving in Irrigated Agriculture)

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14 pages, 1288 KiB

Open AccessArticle

Deficit Irrigation with Ascophyllum nodosum Extract Application as a Strategy to Increase Tomato Yield and Quality

by Vinícius Villa e Vila, Patricia Angélica Alves Marques, Roberto Rezende, Gustavo Soares Wenneck, Daniele de Souza Terassi, André Felipe Barion Alves Andrean, Raiana Crepaldi de Faria Nocchi and Paula Toshimi Matumoto-Pintro

Agronomy 2023, 13(7), 1853; https://doi.org/10.3390/agronomy13071853 - 13 Jul 2023

Cited by 4 | Viewed by 955

Abstract

Deficit irrigation is applied to several agricultural crops as a water-saving irrigation strategy. The tomato plant is sensitive to water stress; however, integration with biostimulant applications, based on seaweed extracts, could be a strategy for plants adapting to this abiotic condition. The objective [...] Read more.

Deficit irrigation is applied to several agricultural crops as a water-saving irrigation strategy. The tomato plant is sensitive to water stress; however, integration with biostimulant applications, based on seaweed extracts, could be a strategy for plants adapting to this abiotic condition. The objective of this study was to evaluate agronomic and quality aspects of tomato cultivated under deficit irrigation combined with Ascophyllum nodosum extract (ANE) application. The experiment was conducted using a completely randomized design with two water replacement levels, 70 and 100% of crop evapotranspiration (ETc), and five doses of ANE (0, 0.1, 0.2, 0.3 and 0.4%) applied via soil drench. The interaction between ANE and ETc was significant (p < 0.05) in terms of plant growth, physiological parameters, fruit yield, yield components and fruit quality. Results indicated that when the tomato plant is under deficit irrigation, a higher ANE dose is required to achieve better development when compared to the 100% ETc condition, where the dose is lower. Under deficit irrigation, the largest fruit yield was obtained with 0.3 and 0.4% ANE, and with 100% ETc, the largest fruit yield was obtained with 0.2% ANE. ANE applications were also effective in increasing plant height, stem diameter, plant biomass, leaf area, chlorophyll and relative water content. In addition, tomato quality was also favored under deficit irrigation and seaweed extract application. We conclude that ANE applications attenuate water deficit effects in tomato plants and provide a strategy to ameliorate tomato yield, tomato quality and water use in agriculture. Full article

(This article belongs to the Special Issue Water Saving in Irrigated Agriculture)

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15 pages, 1264 KiB

Open AccessArticle

Effects of Drip Irrigation and Fertilization Frequency on Yield, Water and Nitrogen Use Efficiency of Medium and Strong Gluten Wheat in the Huang-Huai-Hai Plain of China

by Tianjia Hao, Zixin Zhu, Yulu Zhang, Shuai Liu, Yufan Xu, Xuexin Xu and Changxing Zhao

Agronomy 2023, 13(6), 1564; https://doi.org/10.3390/agronomy13061564 - 07 Jun 2023

Cited by 2 | Viewed by 1351

Abstract

Drip irrigation can reduce water and fertilizer use; however, the frequency of topdressing required for drip irrigation for wheat in the Huang-Huai-Hai region is still unclear. Through two continuous wheat season field experiments, yield related traits under traditional surface irrigation (border irrigation) and [...] Read more.

Drip irrigation can reduce water and fertilizer use; however, the frequency of topdressing required for drip irrigation for wheat in the Huang-Huai-Hai region is still unclear. Through two continuous wheat season field experiments, yield related traits under traditional surface irrigation (border irrigation) and three drip fertilization frequencies (DF2, DF3, DF4, that was, topdressing water and fertilizer twice, three or four times in the same way during the growth period) of three wheat cultivars (Jimai 22, Jimai 20, Shiluan 02-1) were studied. Increasing the frequency of drip irrigation fertilization could prolong the time of high-level photosynthesis, increase the dry matter distribution amount (DMDA) of stems and leaves, and add the weight of 1000 grains; it could increase the DMDA and nitrogen distribution amount (NDA) of the stems, leaves, and grains of Jimai 22, forming higher harvest index (HI) and nitrogen harvest index (NHI), but could reduce the DMDA of the grains of Jimai 20 and Shiluan 02-1, increasing NDA, reducing the harvest index but forming a higher nitrogen harvest index. The increase in drip irrigation fertilization frequency can improve protein content, increase grain number per spike, decrease spike number, improve the yield of medium gluten wheat, and improve nitrogen partial productivity and water use efficiency, while strong gluten wheat has a decrease in yield, nitrogen partial productivity, and water use efficiency. In summary, medium gluten wheat is more suitable for higher fertilization frequency in the Huang-Huai-Hai wheat region, while strong gluten wheat is the opposite. Full article

(This article belongs to the Special Issue Water Saving in Irrigated Agriculture)

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23 pages, 4024 KiB

Open AccessEditor’s ChoiceArticle

A Remote-Sensing-Assisted Estimation of Water Use in Rice Paddy Fields: A Study on Lis Valley, Portugal

by Susana Ferreira, Juan Manuel Sánchez and José Manuel Gonçalves

Agronomy 2023, 13(5), 1357; https://doi.org/10.3390/agronomy13051357 - 12 May 2023

Cited by 2 | Viewed by 1831

Abstract

Rice culture is one of the most important crops in the world, being the most consumed cereal grain (755 million tons in 2020). Since rice is usually produced under flooding conditions and water performs several essential functions for the crop, estimating its water [...] Read more.

Rice culture is one of the most important crops in the world, being the most consumed cereal grain (755 million tons in 2020). Since rice is usually produced under flooding conditions and water performs several essential functions for the crop, estimating its water needs is essential. Remote sensing techniques have shown effectiveness in estimating and monitoring the water use in crop fields. An estimation from satellite data is a challenge, but could be very useful, in order to spatialize local estimates and operationalize production models. This study intended to derive an approach to estimate the actual crop evapotranspiration (ET_a) in rice paddies from a temporal series of satellite images. The experimental data were obtained in the Lis Valley Irrigation District (central coast of Portugal), during the 2019 to 2021 rice growing seasons. The average seasonal ET_a (FAO56) resulted 586 ± 23 mm and the water productivity (WP) was 0.47 ± 0.03 kg m⁻³. Good correlations were found between the crop coefficients (K_c) proposed by FAO and the NDVI evolution in the control rice fields, with R² ranging between 0.71 and 0.82 for stages II+III (development + middle) and between 0.76 and 0.82 for stage IV (late). The results from the derived RS-assisted method were compared to the ET_a values obtained from the surface energy balance model METRIC, showing an average estimation error of ±0.8 mm d⁻¹, with a negligible bias. The findings in this work are promising and show the potential of the RS-assisted method for monitoring ET_a and water productivity, capturing the local and seasonal variability in rice growing, and then predicting the rice yield, being a useful and free tool available to farmers. Full article

(This article belongs to the Special Issue Water Saving in Irrigated Agriculture)

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17 pages, 3932 KiB

Open AccessArticle

Comparison of Evapotranspiration Partitioning and Dual Crop Coefficients of Direct-Seeded and Transplanted Rice in the Poyang Lake Basin, China

by Bo Liu, Jiajia Hou, Hengjun Ge, Meng Liu, Lijie Shi, Cheng Li and Yuanlai Cui

Agronomy 2023, 13(5), 1218; https://doi.org/10.3390/agronomy13051218 - 25 Apr 2023

Cited by 2 | Viewed by 1356

Abstract

Direct-seeded rice (DSR) has received much attention because of its advantages in having low labor costs compared to the traditional transplanted rice (TPR). Investigating the differences in evapotranspiration (ET) partitioning and crop coefficients (K_c) between DSR and TPR is essential in [...] Read more.

Direct-seeded rice (DSR) has received much attention because of its advantages in having low labor costs compared to the traditional transplanted rice (TPR). Investigating the differences in evapotranspiration (ET) partitioning and crop coefficients (K_c) between DSR and TPR is essential in understanding how agricultural water demand is affected by crop rotation. In this study, the water fluxes of two-year (2017–2018) growing seasons were collected from a pair of eddy covariance (EC) towers for DSR and TPR in the Poyang Lake Basin, Southern China. This study aims to compare the seasonal characteristics of the ET components (evaporation, E, and transpiration, T) and dual crop coefficients (basal crop coefficient, K_s·K_cb, and soil/water crop coefficient, K_e) of DSR with those of TPR. The ET values for the 2017 and 2018 growing seasons were 374 mm and 436 mm for the DSR, respectively, and 309 mm and 342 mm for the TPR. The seasonal T/ET values in 2017 and 2018 were 0.40 and 0.46 for the DSR, respectively, and 0.49 and 0.52 for the TPR, indicating that the higher ET values for the DSR can be mostly attributed to E. The DSR had overall higher K_c values than the TPR because of free water evaporation during the initial stage and a higher plant density. Our results enrich the K_c dataset for DSR and have great implications for the sustainable irrigation of the Poyang Lake Basin in the future. Full article

(This article belongs to the Special Issue Water Saving in Irrigated Agriculture)

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21 pages, 8392 KiB

Open AccessArticle

Machine Learning Approach to Predict Flow Regime Index of a Stellate Water-Retaining Labyrinth Channel Emitter

by Yanfei Li, Xianying Feng, Xingchang Han, Yitian Sun and Hui Li

Agronomy 2023, 13(4), 1063; https://doi.org/10.3390/agronomy13041063 - 06 Apr 2023

Viewed by 1151

Abstract

Accurate calculation of the flow regime index in the design and development stage of a drip irrigation emitter plays an essential role. In this study, machine learning technologies were used to establish the relationship between flow channel structural parameters of the novel stellate [...] Read more.

Accurate calculation of the flow regime index in the design and development stage of a drip irrigation emitter plays an essential role. In this study, machine learning technologies were used to establish the relationship between flow channel structural parameters of the novel stellate water-retaining labyrinth channel (SWRLC) irrigation emitter and its flow regime index. The training dataset and test dataset were built by computational fluid dynamics (CFD) simulation and experimental study. The extreme learning machine (ELM), backpropagation neural network (BPNN), and traditional multiple linear regression (MLR) models were developed for the prediction of the flow regime index of the SWRLC emitter. The input parameters matrix consisted of the length of the trapezoid baseline, angle between the hypotenuses of adjacent trapezoids, trapezoid height, radius of stellate water-retaining structure, spacing of two symmetric trapezoids, path depth, and SWRLC unit number, while flow regime index x was the output of the models. The comprehensive indicator (CI) was proposed, and root mean square error (RMSE), mean absolute error (MAE), mean bias error value (MBE), and coefficient of determination (R²) were used to introduce the reliable assessment of the three models. The comparison results showed that the ELM model had the lowest errors, with the CI, RMSE, MAE, and R² were 1.96 × 10⁻¹¹, 0.00163, 0.00126, and 91.49%, respectively. The BPNN model had the lowest MBE error with the value of 1.03 × 10⁻⁴. The ELM and BPNN models were available and had acceptable accuracy for predicting the flow regime index of the emitter, saving both time and cost and increasing efficiency in the design and development stage. According to the CI, the ELM model performed best, followed by the BPNN model with a minor discrepancy. Full article

(This article belongs to the Special Issue Water Saving in Irrigated Agriculture)

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9 pages, 850 KiB

Open AccessCommunication

Decision Support Tool to Predict Panicle Initiation in Aerobic Rice

by Matthew Champness, Carlos Ballester and John Hornbuckle

Agronomy 2023, 13(3), 789; https://doi.org/10.3390/agronomy13030789 - 09 Mar 2023

Viewed by 1108

Abstract

Aerobic rice cultivation offers the potential to reduce irrigated water use. A multitude of challenges, such as cold sterility, drought stress, and labor shortages, limit its adoption in temperate rice-growing regions. Increasing the duration and extent of soil moisture tension between irrigation events [...] Read more.

Aerobic rice cultivation offers the potential to reduce irrigated water use. A multitude of challenges, such as cold sterility, drought stress, and labor shortages, limit its adoption in temperate rice-growing regions. Increasing the duration and extent of soil moisture tension between irrigation events has been demonstrated to slow crop development. Delaying panicle initiation (PI) beyond the optimal window can expose rice to cold nighttime temperatures during the cold sensitive early pollen microspore, severely reducing yield. Tools to assist Australian temperate farmers and researchers in the irrigation management of aerobic rice to ensure PI occurs during the optimal window do not yet exist. Using data collected from an aerobic rice experiment conducted in temperate Australia in 2020–2021 and 2021–2022, a predictive model was built to assist in forecasting PI based on the timing of irrigation. Estimation of the area on an hourly basis of the cumulative evapotranspiration with rainfall subtracted from pre-emergent irrigation to PI, defined as the irrigation deficit integral, was used to account for the frequency, duration, and extent of soil moisture deficit between irrigation events. The relationship between the irrigation deficit integral and the number of days from pre-emergent irrigation to PI (R² = 0.91) was used to build a model to predict PI with a root mean square error of 1.8 days for the validating data set. Furthermore, an example is provided of how the model can be used as a decision support tool to assist researchers and growers to schedule irrigation of aerobic rice to ensure PI occurs in a timely manner. This will increase the likelihood of high-yielding aerobic rice and may enhance the adoption of water-saving rice cultivation. Full article

(This article belongs to the Special Issue Water Saving in Irrigated Agriculture)

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19 pages, 7641 KiB

Open AccessArticle

Responses of the Growth Characteristics of Spinach to Different Moisture Contents in Soil under Irrigation with Magnetoelectric Water

by Yan Sun, Jian Wang, Quanjiu Wang and Chunhong Wang

Agronomy 2023, 13(3), 657; https://doi.org/10.3390/agronomy13030657 - 24 Feb 2023

Cited by 4 | Viewed by 2140

Abstract

Spinach (Spinacia oleracea L.) is a worldwide vegetable crop with rich nutritional value, and drought is the main factor restricting its growth. Magnetized water and de-electronated water have shown potential for improving yield and quality in some crops. To assess the influence [...] Read more.

Spinach (Spinacia oleracea L.) is a worldwide vegetable crop with rich nutritional value, and drought is the main factor restricting its growth. Magnetized water and de-electronated water have shown potential for improving yield and quality in some crops. To assess the influence of magnetized-de-electronated water (denoted magnetoelectric water) on the growth characteristics of spinach, five soil moisture gradients were developed, including 45–55%, 55–65%, 65–75%, 75–85%, and 85–95% of field capacity (FC). The results demonstrated that the influence of irrigation by magnetoelectric water on the growth of spinach was obvious. All the spinach indicators with each soil moisture gradient under irrigation by magnetoelectric water were higher than those of irrigation by conventional water, including the fresh weight of shoots, chlorophyll content, and the total nitrogen content in the leaves. In particular, the improvement in fresh weight of shoots and the total nitrogen contents in the leaves had the highest values, as demonstrated by increases of 52.26% and 25.87%, respectively, under 65–75% of the gradient of FC. Additionally, the fitting results of the photo response curve by different light response models varied. The modified rectangular hyperbolic model was the most accurate for all the treatment groups and thus was the optimized model for the photosynthetic characteristics of spinach under irrigation by magnetoelectric water analysis. The parameters of the photo response curve showed that the dark respiration rate, apparent quantum efficiency, light saturation point, and maximum net photosynthetic rate all increased following irrigation by magnetoelectric water with different soil moisture gradients compared with conventional water irrigation. These research results can provide new technical support for improving the water use efficiency of irrigation water and increasing vegetable production. Full article

(This article belongs to the Special Issue Water Saving in Irrigated Agriculture)

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18 pages, 2268 KiB

Open AccessFeature PaperEditor’s ChoiceArticle

Effect of Soil Moisture Deficit on Aerobic Rice in Temperate Australia

by Matthew Champness, Carlos Ballester and John Hornbuckle

Agronomy 2023, 13(1), 168; https://doi.org/10.3390/agronomy13010168 - 04 Jan 2023

Cited by 7 | Viewed by 2269

Abstract

Declining water availability is pressing rice growers to adopt water-saving irrigation practices such as aerobic rice to maintain profitability per megalitre (ML) of water input. Irrigators require well-defined irrigation thresholds to initiate irrigation to maximise water productivity. Such thresholds do not exist for [...] Read more.

Declining water availability is pressing rice growers to adopt water-saving irrigation practices such as aerobic rice to maintain profitability per megalitre (ML) of water input. Irrigators require well-defined irrigation thresholds to initiate irrigation to maximise water productivity. Such thresholds do not exist for temperate rice regions. Adopting a strategy that has been reported to succeed in non-temperate environments may fail in temperate climates, and therefore, needs investigation. This study aimed to investigate, in a temperate Australian environment, the effect of increasing soil moisture deficit during the rice vegetative period on crop physiological development, grain yield and water productivity. The study was conducted in a commercial farm using a randomised complete block design in the 2020/21 and 2021/22 growing seasons. Automated gravity surface irrigation technologies were adopted to enable high-frequency irrigation. Extending soil moisture deficit beyond 15 kPa was found to significantly delay panicle initiation by at least 13–14 days, exposing rice to cold temperatures in Year 1 during the cold-sensitive early pollen microspore period. This reduced yield by up to 55% (4.5 t/ha) compared to the 15 kPa treatment that was not impacted by cold sterility. In the absence of cold sterility, irrigated water productivity and total water productivity ranged between 1.02 and 1.61 t/ML, and 0.84 and 0.93 t/ML, respectively. The highest yields (8.1 and 7.5 t/ha) were achieved irrigating at a soil tension of 15 kPa in growing seasons 2020/21 and 2021/22. This research demonstrates that sound water productivity can be achieved with aerobic rice cultivation in temperate climates, providing cold temperatures during early pollen microspore are avoided. The quantification of the delay in crop development caused by increasing soil moisture deficit provides rice farmers greater confidence in determining the irrigation strategy and timing of pre-emergent irrigation in regions at risk of cold sterility. However, due to the high labour demand associated with aerobic rice, the adoption of aerobic rice at a commercial scale in this Australian environment is unlikely without adopting automated irrigation technology. Full article

(This article belongs to the Special Issue Water Saving in Irrigated Agriculture)

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13 pages, 536 KiB

Open AccessArticle

Water Saving Using Thermal Imagery-Based Thresholds for Timing Irrigation in Potatoes under Drip and Furrow Irrigation Systems

by Javier Rinza, David A. Ramírez, Johan Ninanya, Felipe de Mendiburu, Jerónimo García and Roberto Quiroz

Agronomy 2022, 12(12), 2921; https://doi.org/10.3390/agronomy12122921 - 23 Nov 2022

Cited by 1 | Viewed by 1720

Abstract

Under the current water crisis in agriculture, irrigation methods for saving and conserving water are necessary. However, these methods must guarantee an appropriate yield with a concomitant economic benefit and a reduced environmental impact. In this study, two irrigation thresholds for irrigation timing [...] Read more.

Under the current water crisis in agriculture, irrigation methods for saving and conserving water are necessary. However, these methods must guarantee an appropriate yield with a concomitant economic benefit and a reduced environmental impact. In this study, two irrigation thresholds for irrigation timing (IT) based on thermal imagery were analyzed with the UNICA potato variety in three trials under drip (DI) and furrow (FI) irrigation during 2017–2018 in Lima, Peru. The control (T1) remained at >70% of soil field capacity. For other treatments, thresholds were defined based on stomatal conductance at light saturation (T2: 0.15 and T3: 0.05 mol

H_{2}

O

m^{- 2}

s^{- 1}

) and crop water stress index (T2: 0.4 and T3: 0.6) based on canopy temperature. An integrated index (IIN) was established for the valuation of treatments using the criteria of high fresh tuber yield (FTY) and a low total amount of irrigated water, production cost (PC), and total C emissions (TE) and using criteria of a score. FI-T2 (0.69–0.72) and DI-T3 (0.19–0.29) showed the highest and lowest IIN value, respectively. FTY in T2 was not significantly reduced under FI, resulting in a lower PC regarding DI–T2 and emphasizing the usefulness of thermal imagery in determining watering schedules in potatoes under furrow irrigation systems. Full article

(This article belongs to the Special Issue Water Saving in Irrigated Agriculture)

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15 pages, 835 KiB

Open AccessArticle

Effects of Different Irrigation and Drainage Modes on Lodging Resistance of Super Rice Japonica 9108

by Shurong Hao, Ting Ding, Xuan Wang, Xia Liu and Yugeng Guo

Agronomy 2022, 12(10), 2407; https://doi.org/10.3390/agronomy12102407 - 05 Oct 2022

Cited by 1 | Viewed by 1263

Abstract

In order to determine the optimal irrigation and drainage mode for the anti-lodging cultivation of Super Rice Japonica 9108, barrel loading tests of different irrigation and drainage modes were carried out in the Water-Saving Park of Hohai University in Nanjing from June to [...] Read more.

In order to determine the optimal irrigation and drainage mode for the anti-lodging cultivation of Super Rice Japonica 9108, barrel loading tests of different irrigation and drainage modes were carried out in the Water-Saving Park of Hohai University in Nanjing from June to October in 2019 and 2020. Three treatments were set up: Frequent and Shallow Irrigation (FSI), Rain-catching and Controlled Irrigation (RC-CI) and Drought Planting with Straw mulching (DPS). In each mode, the growth index, stem morphology index, material production index and stem mechanical index of rice at yellow maturity period were measured, and their relationship with the lodging index was analyzed. The results showed that compared with FSI, the lodging index of RC-CI was reduced by an average of 24.0%. RC-CI can promote the lateral development of the base internodes, increase the accumulation of stem sheath dry matter and the internode fullness and enhance mechanical strength and anti-lodging ability of the stem. Meanwhile, RC-CI can appropriately reduce the plant height, so as to reduce the bending moment of the base internodes. As a consequence, the lodging risk was effectively reduced. The lodging index of DPS was reduced by an average of 16.0% compared with FSI. Because DPS was subject to severe water deficit, its internodes thickness and stem wall thickness were inferior to that of FSI, leading to the weakening of the mechanical strength of stem, and the morphological characteristics and mechanical characteristics of the stem were not improved. Despite this, DPS still had a strong resistance to lodging. The output rate and conversion rate of the stem sheath were reduced, and while the plant height and center of gravity height were significantly reduced, the bending moment remained low. Thus, DPS can still reduce the lodging risk of rice. Compared with FSI, the average yield of RC-CI increased by 5.8% in two years, and the average yield of DPS was reduced by 4.4% in two years. DPS under severe water deficit reduced the accumulation of dry matter in the panicle and the yield index of rice, which was not conducive to a high yield. Considering the yield and lodging resistance of the super rice “Japonica 9108”, RC-CI is the best irrigation and drainage mode, followed by DPS. This study can provide data support and theoretical support for regulating the lodging resistance of super rice through irrigation measures. Full article

(This article belongs to the Special Issue Water Saving in Irrigated Agriculture)

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13 pages, 2700 KiB

Open AccessArticle

An Investigation of the Frequency and Duration of a Drive Spoon–Dispersed Water Jet and Its Influence on the Hydraulic Performance of a Large-Volume Irrigation Sprinkler

by Pan Tang and Chao Chen

Agronomy 2022, 12(9), 2233; https://doi.org/10.3390/agronomy12092233 - 19 Sep 2022

Cited by 1 | Viewed by 1415

Abstract

The frequency and duration of drive spoon–dispersed water jet directly influence the water distribution pattern and, further, affect water distribution uniformity. A mathematical model for calculating the duration was established, and an experiment was carried out to verify the accuracy of the theory [...] Read more.

The frequency and duration of drive spoon–dispersed water jet directly influence the water distribution pattern and, further, affect water distribution uniformity. A mathematical model for calculating the duration was established, and an experiment was carried out to verify the accuracy of the theory by using high-speed photography (HSP) technique. Another important component of the investigation was the influence of frequency and duration on the water distribution pattern and water distribution uniformity. The results showed that the frequency of drive spoon–dispersed water jet increased and the duration time decreased with increased working pressure and decreased distance between counterweight-installed position and rotation axis. The calculated values of the theory were greater than the measured values. Differences between the measured and predicted values decreased with increased working pressure, and the average difference decreased to 2.98% when the working pressure increased to 0.40 MPa. The application rates within 1–13 m improved and increased about 50% by decreasing the distance from 135 mm to 80 mm. The maximum application rates decreased from 10.3 to 9.2 mm h⁻¹, 9.5 to 8.8 mm h⁻¹, and 8.4 to 7.9 mm h⁻¹ with a working pressure of 0.30, 0.35, and 0.40 MPa, respectively. The Christiansen’s uniformity coefficient (CU) values decreased by increasing the distance between the counterweight and the rotation axis. The maximum CU values were obtained at the spacing coefficient of 1.2, 1.2, and 1.1 for 0.30, 0.35, and 0.40 MPa, respectively. By decreasing the distance from 135 mm to 80 mm, the maximum CU values increased from 58.96% to 75.1%, 68.85% to 80.1%, and 72.46% to 82.17% for 0.30, 0.35, and 0.40 MPa, respectively. Full article

(This article belongs to the Special Issue Water Saving in Irrigated Agriculture)

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13 pages, 3909 KiB

Open AccessArticle

The Effect of Plug Height and Inflow Rate on Water Flow Characteristics in Furrow Irrigation

by Juan Yu, Keyao Liu, Anbin Li, Mingfei Yang, Xiaodong Gao, Xining Zhao and Yaohui Cai

Agronomy 2022, 12(9), 2225; https://doi.org/10.3390/agronomy12092225 - 18 Sep 2022

Viewed by 1777

Abstract

Despite its wide application across arid land types, furrow irrigation is often associated with numerous environmental problems related to deep percolation, runoff, and soil erosion. In this study, a straightforward approach was proposed to achieve higher uniformity and reduce erosion. Here, the impacts [...] Read more.

Despite its wide application across arid land types, furrow irrigation is often associated with numerous environmental problems related to deep percolation, runoff, and soil erosion. In this study, a straightforward approach was proposed to achieve higher uniformity and reduce erosion. Here, the impacts that a moveable “plug” has on the behavior of irrigation water in the furrow were simulated using FLOW-3D and HYDRUS-2D, where three plug heights and two flow rates were set. The effect of inflow rate and plug height on the water advance, water level, cumulative infiltration in the furrow, and uniformity coefficient was determined. Results indicate that the plug was able to slow water velocity by approximately 60% in the furrow and increase the furrow advance time by 3–4 times; the water level was increased by nearly 10 cm compared with no plug. Moreover, an irrigation uniformity range of 90.18–99.22% was associated with this plugging. The addition of a plug in the furrow irrigation practices for smallholder farmers in developing countries demonstrates great potential in reducing the probability of erosion under large slopes and can effectively improve irrigation uniformity. Full article

(This article belongs to the Special Issue Water Saving in Irrigated Agriculture)

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16 pages, 4106 KiB

Open AccessArticle

Influence of Micro-Furrow Depth and Bottom Width on Surface Water Flow and Irrigation Performance in the North China Plain

by Songmei Zai, Xuefang Feng, Donglin Wang, Yan Zhang and Feng Wu

Agronomy 2022, 12(9), 2156; https://doi.org/10.3390/agronomy12092156 - 10 Sep 2022

Viewed by 1771

Abstract

Improving traditional surface irrigation technology and vigorously promoting water-saving surface irrigation are important ways to improve the efficiency of water resource utilization. In our study, we propose a new technology of surface irrigation, micro-furrow irrigation, which combines the advantages of furrow irrigation and [...] Read more.

Improving traditional surface irrigation technology and vigorously promoting water-saving surface irrigation are important ways to improve the efficiency of water resource utilization. In our study, we propose a new technology of surface irrigation, micro-furrow irrigation, which combines the advantages of furrow irrigation and border irrigation. The objective of this experiment was to evaluate the effects of micro-furrow depth and bottom width on surface water flow and irrigation performance. Field experiments were conducted from 2019 to 2020 in Zhengzhou City, northern China. This work designed three bottom widths, BW1 (18 cm), BW2 (12 cm), and BW3 (6 cm), respectively, and three depths, D1 (15 cm), D2 (10 cm), and D3 (5 cm), respectively. Moreover, border irrigation was set as control treatment (CK). Additionally, field experiments were validated and simulated using the WinSRFR 5.1 model (Arid-Land Agricultural Research Center, USA). The results showed a significant negative correlation between depth and advance time and between depth and recession time. However, no significant correlation was found between bottom width and advance time, nor between bottom width and recession time. The advance times of micro-furrow irrigation were 1.23–4.77 min less than those of border irrigation. Concerning irrigation performance, compared to that of border irrigation, the application efficiency and distribution uniformity increased by 8–30% and −5–18%, respectively. However, the requirement efficiency decreased by 0–40%. Compared to that of border irrigation, the irrigation quota increased 21.61% under BW3D3 but decreased by 10.46–57.94% under other treatments. Therefore, micro-furrow irrigation can meet irrigation requirements despite low irrigation quota. Comprehensively considering the advance time, recession time, irrigation performance, and irrigation quota, we recommend a micro-furrow shape with a depth of 10 cm or 15 cm and bottom width of 6 cm. Full article

(This article belongs to the Special Issue Water Saving in Irrigated Agriculture)

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15 pages, 1243 KiB

Open AccessArticle

Tomato Comprehensive Quality Evaluation and Irrigation Mode Optimization with Biogas Slurry Based on the Combined Evaluation Model

by Jian Zheng, Xingyun Qi, Cong Shi, Shaohong Yang and You Wu

Agronomy 2022, 12(6), 1391; https://doi.org/10.3390/agronomy12061391 - 09 Jun 2022

Cited by 6 | Viewed by 2036

Abstract

Scientific and reasonable water and fertilizer regimes positively affected crop growth, yield, fruits quality and soil environment improvement. As a liquid quick-acting organic fertilizer to substitute chemical fertilizers, biogas slurry has been widely used in agricultural production. However, the lack of research on [...] Read more.

Scientific and reasonable water and fertilizer regimes positively affected crop growth, yield, fruits quality and soil environment improvement. As a liquid quick-acting organic fertilizer to substitute chemical fertilizers, biogas slurry has been widely used in agricultural production. However, the lack of research on the proper comprehensive quality evaluation model and irrigation mode under biogas slurry limits the promotion and large-scale application of biogas slurry in agricultural production. In this study, three biogas slurry (BS) ratio (1:4BS, 1:6BS, 1:8BS; volume ratio of biogas slurry to water), three irrigation levels (W1, W2, W3) and three fertilizer control treatments (CF1, CF2, CF3) were conducted in field experiments. Eleven single indexes from four type qualities (external quality, taste quality, nutrition quality, storage and transportation quality) were adopted to establish the comprehensive evaluation index system of tomato. The principal component analysis, grey correlation analysis, membership function analysis and TOPSIS analysis model (based on the combination of objective entropy method and subjective analytic hierarchy process) were used to estimate the comprehensive quality of tomato fruits. Moreover, the objective combination evaluation mode based on overall diversity was used to evaluate the results obtained from the four independent comprehensive evaluation methods. The aim is to mitigate inconsistencies of multi-attribute evaluation models. The results showed that biogas slurry application was beneficial to the accumulation of aboveground biomass under the same irrigation amount, which can effectively improve the sugar to acid ratio and lycopene content of tomato. T3 (1:4BS, W3) and T1 (1:4BS, W1) obtained the highest yield and water use efficiency (WUE), respectively. The results of Kendall consistency test and Pearson correlation coefficients showed that there were good compatibility and high consistency among the four independent comprehensive evaluation models, and the combined quality evaluation model can be performed directly. As the correlation coefficients between combined evaluation model and each of four independent methods reached 0.965, the combined evaluation model was capable of reducing the differences of four independent comprehensive evaluation model. The combined quality evaluation results showed that T2 (1:4BS, W2) recommended strongly in this study could effectively improve the yield, quality and WUE of tomato. Full article

(This article belongs to the Special Issue Water Saving in Irrigated Agriculture)

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20 pages, 4263 KiB

Open AccessArticle

Effect of Organic Amendments and Nano-Zinc Foliar Application on Alleviation of Water Stress in Some Soil Properties and Water Productivity of Barley Yield

by Tamer H. Khalifa, Samah A. Mariey, Zeinab E. Ghareeb, Ismael A. Khatab and Amal Alyamani

Agronomy 2022, 12(3), 585; https://doi.org/10.3390/agronomy12030585 - 26 Feb 2022

Cited by 2 | Viewed by 2362

Abstract

The scarcity of water resources in arid and semi-arid areas is considered a threat to agricultural sustainability. Therefore, approaches are needed to rationalize use of irrigation water without reducing crop productivity or degrading soil properties. The objective of this study was to investigate [...] Read more.

The scarcity of water resources in arid and semi-arid areas is considered a threat to agricultural sustainability. Therefore, approaches are needed to rationalize use of irrigation water without reducing crop productivity or degrading soil properties. The objective of this study was to investigate the effect of different organic amendments (O₁ = control, O₂ = compost, and O₃ = vermicompost) combined with different rates of nano- zinc foliar spraying (Zn₁ = 0, Zn₂ = 1 and Zn₃ = 2 gm/L), under irrigation supplements (I₁ = 100%, I₂ = 85%, and I₃ = 65% of water requirements) on clay soil characteristics, on the production of Egyptian barley Giza 126. Over two successive winter growing seasons, 2018/2019 and 2019/2020, field experiments were conducted as a split-split plot design with three replications. The results show that using vermicompost is an appropriate organic amendment to improve the physical and chemical properties of soils as compared with compost. Application of vermicompost led to a reduction in soil salinity (ECe), exchangeable sodium percentage (ESP), and soil bulk density (BD), of −5.67%, −5.44%, and −2.21%, respectively; there was a significant increase in soil organic carbon (SOC), available nitrogen (A.N), and field capacity (F.C.), of 43.75%, 14.37%, and 18.65%, respectively, compared with unamended soil (O₁). The maximum values for grain yield were increased by 13.2% and 14.9% in both seasons, respectively, and the irrigation water productivity of barley was increased more than compost and control. Vermicompost increased the irrigation water productivity for grain (1.69 and 1.69 kg grain m⁻³) and straw (1.23 and 1.17 kg straw m⁻³) in the first and second season, respectively. Similar trends were also observed from treatments on the water applied, stored water, and water application efficiency. Application of vermicompost and nano-Zn foliar spraying could be exploited for the development of barley growth and yield, which are enhanced under water-saving irrigation strategies. Full article

(This article belongs to the Special Issue Water Saving in Irrigated Agriculture)

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17 pages, 13612 KiB

Open AccessArticle

Ebb-and-Flow Subirrigation Improves Seedling Growth and Root Morphology of Tomato by Influencing Root-Softening Enzymes and Transcript Profiling of Related Genes

by Kelei Wang, Muhammad Moaaz Ali, Keke Pan, Shiwen Su, Jian Xu and Faxing Chen

Agronomy 2022, 12(2), 494; https://doi.org/10.3390/agronomy12020494 - 16 Feb 2022

Cited by 5 | Viewed by 2746

Abstract

Ebb-and-flow subirrigation is a promising strategy to increase water use efficiency, avoid waterlogging or drought conditions, and promote the overall growth of vegetable crops. The aim of this study was to evaluate the seedling growth, root morphology, activities of root-softening enzymes, and transcript [...] Read more.

Ebb-and-flow subirrigation is a promising strategy to increase water use efficiency, avoid waterlogging or drought conditions, and promote the overall growth of vegetable crops. The aim of this study was to evaluate the seedling growth, root morphology, activities of root-softening enzymes, and transcript profiling of those enzyme-related genes in tomato under top sprinkle irrigation and ebb-and-flow subirrigation. The results showed that ebb-and-flow subirrigation could significantly improve stem diameter, root fresh weight, root dry weight, root volume, and root diameter of tomato by 9.42%, 45.92%, 44.82%, 15.61%, and 9.41%, as compared with top sprinkle irrigation, respectively. The ebb-and-flow subirrigation also maintained the root activity and photosynthetic rate of tomato seedlings. The activities of superoxidase dismutase, peroxidase, catalase, glutathione reductase, and ascorbate peroxidase of tomato roots under ebb-and-flow subirrigation were remarkably increased, while the malondialdehyde content was decreased compared with the plants grown under top sprinkle irrigation. Correlation analysis among activities of root-softening enzymes and transcriptomic profiling of their biosynthesis-related genes revealed that 10 genes might be responsible for regulation of studied enzymes. Overall, ebb-and-flow subirrigation could significantly promote the growth of tomato seedlings, so as to maintain high activity and promote the cultivation of high-quality and strong seedlings. Full article

(This article belongs to the Special Issue Water Saving in Irrigated Agriculture)

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21 pages, 2582 KiB

Open AccessArticle

Performance of Hybrid Wheat Cultivars Facing Deficit Irrigation under Semi-Arid Climate in Pakistan

by Muhammad Mehran Anjum, Muhammad Arif, Muhammad Riaz, Kashif Akhtar, Sheng Quan Zhang and Chang Ping Zhao

Agronomy 2021, 11(10), 1976; https://doi.org/10.3390/agronomy11101976 - 30 Sep 2021

Cited by 7 | Viewed by 2964

Abstract

Predicted decrease in water availability for crop production and uncertainty in climatic conditions require devising the irrigation strategies to increase water use efficiency (WUE) for sustainable crop production. The development of crop cultivars with higher WUE is a pre-requisite for such strategies, particularly [...] Read more.

Predicted decrease in water availability for crop production and uncertainty in climatic conditions require devising the irrigation strategies to increase water use efficiency (WUE) for sustainable crop production. The development of crop cultivars with higher WUE is a pre-requisite for such strategies, particularly in developing countries, including Pakistan, who face stern food security challenges. A two-year field study was conducted following a split-plot randomized complete block design to understand the effects of wheat cultivars (hybrid cultivars, 18A-1 and 18A-2, and local cultivar Ghaneemat IBGE-2016), sowing dates (15th November, 30th November, and 15th December), and irrigation regimes [I (103 mm), II (175 mm), III (254 mm), and IV (330 mm)] at four different growth stages of tillering, booting, anthesis and grain filling on wheat productivity, biomass production and grain yield, and crop-water relations. Early sown hybrid cultivars 18A-1 and 18A-2 showed significantly higher biological and grain yields compared to the local cultivar (59% and 69% higher than the local cultivar). Trends in biomass production and grain yield were also similar at later sowing dates of 30th November and 15th December. However, biological and grain yields decreased with delay in sowing for each cultivar. The data also revealed that hybrid cultivars were better suited to deficient irrigation and generally produced significantly higher biological and grain yields under each moisture regime. Cultivars, sowing dates, and irrigation regime differed significantly for their effects on the Soil Plant Analysis Development (SPAD) values, chlorophyll a and b contents but not for carotenoids. Sowing dates and irrigation regimes had significant effects on relative water content (RWC), water saturation deficit (WSD), water uptake capacity (WUC), and water retention capacity (WRC); however, only WUC varied significantly between the cultivars. The phenological data show that hybrid cultivars took more days to maturity and grain filling than the local cultivar, and days decreased with delayed sowing. The biological and grain yields show significant positive correlations with SPAD values (p < 0.001) and days to maturity (p < 0.001). Our study shows that hybrid wheat cultivars can be opted for higher biomass production and grain yields under deficit irrigation scenarios of semi-arid climatic conditions in Pakistan. Moreover, the hybrid wheat cultivars can perform better than the indigenous cultivar even for delayed sowing dates of 30th November and 15th December. Full article

(This article belongs to the Special Issue Water Saving in Irrigated Agriculture)

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16 pages, 1569 KiB

Open AccessArticle

Climate Change Adaptation Measures in the Irrigation of a Super-Intensive Olive Orchard in the South of Portugal

by Sofia Branquinho, João Rolim and José Luís Teixeira

Agronomy 2021, 11(8), 1658; https://doi.org/10.3390/agronomy11081658 - 20 Aug 2021

Cited by 13 | Viewed by 2873

Abstract

The south of Portugal is one of the regions that will be most affected by the impacts of climate change (CC), with an expected increase in water scarcity. Irrigated super-intensive olive orchards occupy a large area of the used agricultural surface in the [...] Read more.

The south of Portugal is one of the regions that will be most affected by the impacts of climate change (CC), with an expected increase in water scarcity. Irrigated super-intensive olive orchards occupy a large area of the used agricultural surface in the Alentejo region, south of Portugal, making it necessary to adapt this crop to the effects of CC. This study assessed the impacts of CC and defined adaptation measures concerning irrigation management of the super-intensive olive orchard. To compute the crop irrigation requirement (CIR), the soil water balance model ISAREG was combined with climate data relative to the reference period 1971–2000 and to the representative concentration pathways RCP4.5 and RCP8.5 for the periods 2011–2040, 2041–2070, and 2071–2100. The growing degree-days (GDD) approach was used to estimate olive phenology for these CC scenarios. Unchanged irrigation management with an average CIR increase up to 16% in RCP4.5 and 31% in RCP8.5 is expected. By adopting higher levels of water deficit, water savings of up to 22% can be realized. The results showed that the anticipated CIR increase for the CC scenarios can be mitigated through regulated deficit irrigation strategies. Full article

(This article belongs to the Special Issue Water Saving in Irrigated Agriculture)

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14 pages, 6188 KiB

Open AccessArticle

Evapotranspiration and Crop Coefficient of Ratoon Rice Crop Determined by Water Depth Observation and Bayesian Inference

by Shutaro Shiraki, Thin Mar Cho, Yutaka Matsuno and Yoshiyuki Shinogi

Agronomy 2021, 11(8), 1573; https://doi.org/10.3390/agronomy11081573 - 06 Aug 2021

Cited by 2 | Viewed by 2164

Abstract

Actual crop evapotranspiration (ET) and crop coefficient (Kc) of ratoon rice crop, which are necessary for irrigation planning, have been hardly reported. ET can be directly measured by lysimeter and eddy covariance but it is expensive, so it remains difficult to determine ET, [...] Read more.

Actual crop evapotranspiration (ET) and crop coefficient (Kc) of ratoon rice crop, which are necessary for irrigation planning, have been hardly reported. ET can be directly measured by lysimeter and eddy covariance but it is expensive, so it remains difficult to determine ET, especially in developing countries. The focus of this study was to evaluate the ET and Kc of ratoon cropping in a tropical region of Myanmar using a simplified method. Our method combined the manual observation of water depth in concrete paddy tanks and the ET model estimation using Bayesian parameter inference. The ET and Kc could be determined using this method with an incomplete observation dataset. The total ET of ratoon was 60–70% less than that of the main crop, but this difference was mainly attributed to climate conditions in each cultivation. The Kc regression curve between transplanted rice and ratoon crops was different because of the tillering traits. The results suggest that irrigation scheduling of ratoon cropping in the initial growth stage should take high crop water requirements into account. In addition, the productivity of ratoon crop is equivalent to transplanted rice, which was determined for cultivation in experiment conditions of small concrete tanks. Therefore, further study on ratoon in Myanmar is necessary for clarifying the viability of ratoon cropping. Full article

(This article belongs to the Special Issue Water Saving in Irrigated Agriculture)

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13 pages, 1479 KiB

Open AccessArticle

Canopy Temperature as a Key Physiological Trait to Improve Yield Prediction under Water Restrictions in Potato

by Johan Ninanya, David A. Ramírez, Javier Rinza, Cecilia Silva-Díaz, Marcelo Cervantes, Jerónimo García and Roberto Quiroz

Agronomy 2021, 11(7), 1436; https://doi.org/10.3390/agronomy11071436 - 20 Jul 2021

Cited by 8 | Viewed by 4425

Abstract

Canopy temperature (CT) as a surrogate of stomatal conductance has been highlighted as an essential physiological indicator for optimizing irrigation timing in potatoes. However, assessing how this trait could help improve yield prediction will help develop future decision support tools. In this study, [...] Read more.

Canopy temperature (CT) as a surrogate of stomatal conductance has been highlighted as an essential physiological indicator for optimizing irrigation timing in potatoes. However, assessing how this trait could help improve yield prediction will help develop future decision support tools. In this study, the incorporation of CT minus air temperature (dT) in a simple ecophysiological model was analyzed in three trials between 2017 and 2018, testing three water treatments under drip (DI) and furrow (FI) irrigations. Water treatments consisted of control (irrigated until field capacity) and two-timing irrigation based on physiological thresholds (CT and stomatal conductance). Two model perspectives were implemented based on soil water balance (P1) and using dT as the penalizing factor (P2), affecting the biomass dynamics and radiation use efficiency parameters. One of the trials was used for model calibration and the other two for validation. Statistical indicators of the model performance determined a better yield prediction at harvest for P2, especially under maximum stress conditions. The P1 and P2 perspectives showed their highest coefficient of determination (R

^{2}

) and lowest root-mean-squared error (RMSE) under DI and FI, respectively. In the future, the incorporation of CT combining low-cost infrared devices/sensors with spatial crop models, satellite image information, and telemetry technologies, an adequate decision support system could be implemented for water requirement determination and yield prediction in potatoes. Full article

(This article belongs to the Special Issue Water Saving in Irrigated Agriculture)

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14 pages, 2219 KiB

Open AccessArticle

Identifying Within-Field Spatial and Temporal Crop Water Stress to Conserve Irrigation Resources with Variable-Rate Irrigation

by Jeffrey D. Svedin, Ruth Kerry, Neil C. Hansen and Bryan G. Hopkins

Agronomy 2021, 11(7), 1377; https://doi.org/10.3390/agronomy11071377 - 07 Jul 2021

Cited by 4 | Viewed by 2201

Abstract

Addressing within-field and within-season variability of crop water stress is critical for spatially variable irrigation. This study measures interactions between spatially variable soil properties and temporally variable crop water dynamics; and whether modelling soil water depletion is an effective approach to guide variable-rate [...] Read more.

Addressing within-field and within-season variability of crop water stress is critical for spatially variable irrigation. This study measures interactions between spatially variable soil properties and temporally variable crop water dynamics; and whether modelling soil water depletion is an effective approach to guide variable-rate irrigation (VRI). Energy and water balance equations were used to model crop water stress at 85 locations within a 22 ha field of winter wheat (Triticum aestivum L.) under uniform and spatially variable irrigation. Significant within-field variability of soil water holding capacity (SWHC; 145–360 mm 1.2 m⁻¹), soil electrical conductivity (0.22–49 mS m⁻¹), spring soil water (314–471 mm 1.2 m⁻¹), and the onset of crop water stress were observed. Topographic features and modelled onset of crop water stress were significant predictors of crop yield while soil moisture at spring green-up, elevation, and soil electrical conductivity were significant predictors of the onset of crop water stress. These results show that modelling soil water depletion can be an effective scheduling tool in VRI. Irrigation zones and scheduling efforts should consider expanding to include temporally dynamic factors, including spring soil water content and the onset of crop water stress. Full article

(This article belongs to the Special Issue Water Saving in Irrigated Agriculture)

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16 pages, 4173 KiB

Open AccessArticle

Exploring the Use of Vegetation Indices for Validating Crop Transpiration Fluxes Computed with the MOHID-Land Model. Application to Vineyard

by Tiago B. Ramos, Lucian Simionesei, Ana R. Oliveira, Ramiro Neves and Hanaa Darouich

Agronomy 2021, 11(6), 1228; https://doi.org/10.3390/agronomy11061228 - 17 Jun 2021

Cited by 3 | Viewed by 1697

Abstract

The success of an irrigation decision support system (DSS) much depends on the reliability of the information provided to farmers. Remote sensing data can expectably help validate that information at the field scale. In this study, the MOHID-Land model, the core engine of [...] Read more.

The success of an irrigation decision support system (DSS) much depends on the reliability of the information provided to farmers. Remote sensing data can expectably help validate that information at the field scale. In this study, the MOHID-Land model, the core engine of the IrrigaSys DSS, was used to simulate the soil water balance in an irrigated vineyard located in southern Portugal during three growing seasons. Modeled actual basal crop coefficients and transpiration rates were then compared with the corresponding estimates derived from the normalized difference vegetation index (NDVI) computed from Sentinel-2 imagery. On one hand, the hydrological model was able to successfully estimate the soil water balance during the monitored seasons, exposing the need for improved irrigation schedules to minimize percolation losses. On the other hand, remote sensing products found correspondence with model outputs despite the conceptual differences between both approaches. With the necessary precautions, those products can be used to complement the information provided to farmers for irrigation of vine crop, further contributing to the regular validation of model estimates in the absence of field datasets. Full article

(This article belongs to the Special Issue Water Saving in Irrigated Agriculture)

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17 pages, 19295 KiB

Open AccessFeature PaperArticle

Evaluation of NASA POWER Reanalysis Products to Estimate Daily Weather Variables in a Hot Summer Mediterranean Climate

by Gonçalo C. Rodrigues and Ricardo P. Braga

Agronomy 2021, 11(6), 1207; https://doi.org/10.3390/agronomy11061207 - 14 Jun 2021

Cited by 28 | Viewed by 4357

Abstract

This study aims to evaluate NASA POWER reanalysis products for daily surface maximum (Tmax) and minimum (Tmin) temperatures, solar radiation (Rs), relative humidity (RH) and wind speed (Ws) when compared with observed data from 14 distributed weather stations across Alentejo Region, Southern Portugal, [...] Read more.

This study aims to evaluate NASA POWER reanalysis products for daily surface maximum (Tmax) and minimum (Tmin) temperatures, solar radiation (Rs), relative humidity (RH) and wind speed (Ws) when compared with observed data from 14 distributed weather stations across Alentejo Region, Southern Portugal, with a hot summer Mediterranean climate. Results showed that there is good agreement between NASA POWER reanalysis and observed data for all parameters, except for wind speed, with coefficient of determination (R²) higher than 0.82, with normalized root mean square error (NRMSE) varying, from 8 to 20%, and a normalized mean bias error (NMBE) ranging from –9 to 26%, for those variables. Based on these results, and in order to improve the accuracy of the NASA POWER dataset, two bias corrections were performed to all weather variables: one for the Alentejo Region as a whole; another, for each location individually. Results improved significantly, especially when a local bias correction is performed, with Tmax and Tmin presenting an improvement of the mean NRMSE of 6.6 °C (from 8.0 °C) and 16.1 °C (from 20.5 °C), respectively, while a mean NMBE decreased from 10.65 to 0.2%. Rs results also show a very high goodness of fit with a mean NRMSE of 11.2% and mean NMBE equal to 0.1%. Additionally, bias corrected RH data performed acceptably with an NRMSE lower than 12.1% and an NMBE below 2.1%. However, even when a bias correction is performed, Ws lacks the performance showed by the remaining weather variables, with an NRMSE never lower than 19.6%. Results show that NASA POWER can be useful for the generation of weather data sets where ground weather stations data is of missing or unavailable. Full article

(This article belongs to the Special Issue Water Saving in Irrigated Agriculture)

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13 pages, 711 KiB

Open AccessArticle

Impact of Different Water Management Regimes on the Growth, Productivity, and Resource Use Efficiency of Dry Direct Seeded Rice in Central Punjab-Pakistan

by Sadam Hussain, Saddam Hussain, Zubair Aslam, Muhammad Rafiq, Adeel Abbas, Muhammad Saqib, Abdur Rauf, Christophe Hano and Mohamed A. El-Esawi

Agronomy 2021, 11(6), 1151; https://doi.org/10.3390/agronomy11061151 - 04 Jun 2021

Cited by 5 | Viewed by 2855

Abstract

Dry direct-seeded rice has been shown to save irrigation water and labor. Nonetheless, irrigation management in dry direct-seeded rice has received very little attention. Here, we examined the potential of different irrigation regimes: aerobic rice (AR), alternate wetting and drying (AWD) and continuous [...] Read more.

Dry direct-seeded rice has been shown to save irrigation water and labor. Nonetheless, irrigation management in dry direct-seeded rice has received very little attention. Here, we examined the potential of different irrigation regimes: aerobic rice (AR), alternate wetting and drying (AWD) and continuous flooding (CF) in dry direct-seeded rice cultivation on two rice cultivars (Pride-1 (hybrid indica) and NB-1 (inbred indica)). Growth, yield attributes, grain yield, total water input, water productivity and benefit cost ratio were measured. Our results showed that AR saved 11.22 and 28.40%, and 5.72 and 32.98% water compared with AWD and CF during 2018 and 2020, respectively. There was a significant difference in grain yield among treatments and cultivars. AWD and CF produced statistically same total dry weight and grain yield, while AR reduced the total dry weight by 31.34% and 38.04% and grain yield by 34.82% and 38.16% in comparison to AWD and CF, respectively, across the years. Except for 1000-grain weight and harvest index in AWD and CF, further differences in total dry weight and grain yield among irrigation treatments were primarily correlated with variations in yield attributes. Among the cultivars, hybrid rice performed better than inbred rice. Over the two-year period, hybrid rice increased total dry weight, grain yield, and water productivity by 9.28%, 13.05%, and 14.28%, respectively, as compared to inbred rice. Regarding water productivity (WP), the maximum percentage (40.90 and 26.53%) was recorded for AWD compared to AR and CF. Among cultivars, more water productivity (14.28%) was calculated for hybrid rice than inbred one. Chlorophyll and carotenoid contents, leaf area index and crop growth rate contributed to higher grain yield of hybrid rice under AWD and CF. In contrast to WP, the maximum benefit cost ratio was estimated to be higher for CF than that of AR and AWD. For the cultivars, the maximum value (2.26 in 2018 and 2.32 in 2020) was calculated for hybrid rice compared with the inbred one. In conclusion, these results suggests that AWD with maximum WP and CF with maximum BCR could be more efficient approaches than AR. Under CF, hybrid rice cultivars with higher yield and yield-related attributes, WP and BCR performed better. Full article

(This article belongs to the Special Issue Water Saving in Irrigated Agriculture)

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12 pages, 3116 KiB

Open AccessArticle

Investigation of Effective Irrigation Strategies for High-Density Apple Orchards in Pennsylvania

by Xiaohu Jiang and Long He

Agronomy 2021, 11(4), 732; https://doi.org/10.3390/agronomy11040732 - 10 Apr 2021

Cited by 13 | Viewed by 4474

Abstract

Irrigation helps grow agricultural crops in dry areas and during periods of inadequate rainfall. Proper irrigation could improve both crop productivity and produce quality. For high density apple orchards, water relations are even more important. Most irrigation in tree fruit orchards is applied [...] Read more.

Irrigation helps grow agricultural crops in dry areas and during periods of inadequate rainfall. Proper irrigation could improve both crop productivity and produce quality. For high density apple orchards, water relations are even more important. Most irrigation in tree fruit orchards is applied based on grower’s experience or simple observations, which may lead to over- or under-irrigation. To investigate an effective irrigation strategy in high-density apple orchard, three irrigation methods were tested including soil moisture-based, evapotranspiration (ET)-based and conventional methods. In soil moisture-based irrigation, soil water content and soil water potential sensors were measured side by side. In ET-based irrigation, daily ET (ET_c) and accumulated water deficit were calculated. Conventional method was based on the experience of the operator. The experiment was conducted from early June through middle of October (one growing season). Lastly, water consumption, fruit yield and fruit quality were analyzed for these irrigation strategies. Results indicated that the soil moisture-based irrigation used least water, with 10.8% and 4.8% less than ET-based and conventional methods, respectively. The yield from the rows with the soil moisture-based irrigation was slightly higher than the other two, while the fruit quality was similar. The outcome from this study proved the effectiveness of using soil moisture sensors for irrigation scheduling and could be an important step for future automatic irrigation system. Full article

(This article belongs to the Special Issue Water Saving in Irrigated Agriculture)

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14 pages, 1017 KiB

Open AccessArticle

Determining Farmers’ Willingness to Pay for Irrigation Water in the Alentejo Region (Southern Portugal) by the Residual Value Method

by Gonçalo C. Rodrigues, Francisco G. da Silva and José C. Coelho

Agronomy 2021, 11(1), 142; https://doi.org/10.3390/agronomy11010142 - 13 Jan 2021

Cited by 8 | Viewed by 3159

Abstract

This paper aims to determine farmers’ willingness to pay for irrigation water, using the residual value method, for the most representative crops at six Irrigation Communities from the Alentejo region, southern Portugal. The main objective of this assessment was to determine the value [...] Read more.

This paper aims to determine farmers’ willingness to pay for irrigation water, using the residual value method, for the most representative crops at six Irrigation Communities from the Alentejo region, southern Portugal. The main objective of this assessment was to determine the value that farmers would be able to pay for the water to irrigate different crops at different locations, and to show that this approach can be used to provide information about farming economic sustainability and provide support on if crop prices need to be revised or if a national policy should be conceived to cover for farming costs. The results show that vegetables and fruit trees have the highest Residual Value of Water (RV_W), while Wheat, Sunflower, Fodder crops, Semi-intensive Olive Orchards and Rice tend to have an RV_W lower than the current variable irrigation water price. The results also show that, while, for Melon, Tomato, Onion, Super-high-density Olive Orchards, Peach and Almonds, both yields and price may decrease significantly, allowing one to save for faming inputs, Sunflower and Rice would require an increase in yields or prices to cover for the irrigation water price. Full article

(This article belongs to the Special Issue Water Saving in Irrigated Agriculture)

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25 pages, 4068 KiB

Open AccessArticle

Water Saving and Yield of Potatoes under Partial Root-Zone Drying Drip Irrigation Technique: Field and Modelling Study Using SALTMED Model in Saudi Arabia

by Abdulrasoul Al-Omran, Ibrahim Louki, Arafat Alkhasha, Mohamed Hassan Abd El-Wahed and Abdullah Obadi

Agronomy 2020, 10(12), 1997; https://doi.org/10.3390/agronomy10121997 - 19 Dec 2020

Cited by 8 | Viewed by 2462

Abstract

This study aims to evaluate the Partial Root Zone Drying Irrigation System (PRD) as one of the modern technologies that provide irrigation water and increase the efficiency of its use on potato crop. The effect of applying the PRD conventional deficit irrigation (CDI) [...] Read more.

This study aims to evaluate the Partial Root Zone Drying Irrigation System (PRD) as one of the modern technologies that provide irrigation water and increase the efficiency of its use on potato crop. The effect of applying the PRD conventional deficit irrigation (CDI) on the efficiency and water saving in potato crops using the drip surface (S) and subsurface (SS) irrigation methods were investigated. SALTMED model used to predict soil moisture and salinity distribution, soil nitrogen dynamics, and yield of potato crop using the different irrigation levels (150%, 100%, and 50% of Crop evapotranspiration (ETc)). The study showed that the water use efficiency (WUE) decreases with increasing levels of irrigation water, as it ranged between 2.96 and 8.38 kgm⁻³, 2.77 and 7.01 kgm⁻³ for surface irrigation PRD and CDI, respectively, when the amounts of irrigation water varied from 308 mm to 1174 mm, respectively. The study showed that the irrigation efficiencies were the highest when using PRD system in all treatments when irrigating the potato crop during the spring season, and it was more efficient in the case of using subsurface irrigation method. The results show that the soil moisture (SM) was high in 25–45 cm at 150% of ETc was 0.166 and 0.263 m³m⁻³ for the first and last stages of growth, respectively. 100% of ETc, (SM) was 0.296 m³m⁻³ at 0–25 cm, 0.195 m³m⁻³ at 25–45 cm, 0.179 m³m⁻³ at 45–62 cm, depths, respectively. whereas 50% of ETc, (SM) was 0.162 m³m⁻³ at 0–25 cm, 0.195 m³m⁻³ at 25–85 cm, depths. At 100% of ETc, soil salinity was 5.15, 4.37, 3.3, and 4.5 dSm⁻¹, whereas at 50%, ETc, these values were 5.64, 9.6, 3.3, and 4.2 dSm⁻¹. Statistical indicators showed that the model underestimated yield, for 150%, 100%, and 50% of ETc. Therefore, it can be concluded that yield and WUE using PRD systems were the highest in the potato crop compare to CDI surface and sub-surface, and SALTMED model can predict the moisture distribution, salinity, and yield of potatoes after accurate adjustment. Full article

(This article belongs to the Special Issue Water Saving in Irrigated Agriculture)

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