Research

13 pages, 2836 KiB

Open AccessArticle

Reduced Nitrogen Input Combined with Nitrogen-Saving japonica Rice Varieties Balances Yield and Nitrogen Use Efficiency in The Lower Reaches of the Yangtze River in China

by Xiaoxiang Zhang, Honggen Zhang, Zi Wang, Yingbo Gao, Xin Liu, Xiaowei Shu, Yueqi Chen, Ning Xiao, Cunhong Pan, Juan Zhou, Chunming Ji, Guichun Dong, Niansheng Huang, Jianye Huang, Aihong Li and Youli Yao

Agronomy 2023, 13(7), 1832; https://doi.org/10.3390/agronomy13071832 - 11 Jul 2023

Viewed by 766

Abstract

Maintaining rice yield and reducing nitrogen (N) input are two important targets in sustainable agriculture practices. The adoption of a nitrogen-saving variety (NSV) provides a unique opportunity to achieve this. However, limited options in NSV japonica rice and a lack of information on [...] Read more.

Maintaining rice yield and reducing nitrogen (N) input are two important targets in sustainable agriculture practices. The adoption of a nitrogen-saving variety (NSV) provides a unique opportunity to achieve this. However, limited options in NSV japonica rice and a lack of information on their responses to N reduction make management decisions difficult. This study aims to explore the responses of yield and nitrogen use efficiency (NUE) in NSV to N reduction. Two newly released NSVs and two popular general varieties (GVs) of japonica rice were field tested in Yangzhou, located at the lower reaches of Yangtze River of China, in two consecutive years. The results showed that for NSVs, with a 40–60% reduction in common practice N rate (300 Kg ha⁻¹), the rice yield could maintain a record average level (p < 0.05), whereas the yield for the GV would drop 20–30% (p < 0.05). This indicates that combining the practices of adoption of NSV and N reduction to 120–180 Kg N ha⁻¹ could balance the yield and N consumption. Moderate N reduction promotes the N accumulation and NUE, and it increases the number of tillers, the productive tiller percentage and the total amount of spikelets in the population, and increases the carbon and N metabolism of the population in the NSV. Compared with GV, NSV showed higher NUE and non-structural carbohydrate re-mobilization in the reduced N rate. The results showed that the practice of N reduction has to adopt NSV at the same time in order to maintain the grain yield level in rice. Full article

(This article belongs to the Special Issue Crop Yield Formation and Fertilization Management)

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18 pages, 3374 KiB

Open AccessArticle

Revolutionizing Maize Crop Productivity: The Winning Combination of Zigzag Planting and Deep Nitrogen Fertilization for Maximum Yield through Root–Shoot Ratio Management

by Yongzhao Zheng, Yang Yue, Congfeng Li, Yongjun Wang, Hongyu Zhang, Hong Ren, Xiangwei Gong, Ying Jiang and Hua Qi

Agronomy 2023, 13(5), 1307; https://doi.org/10.3390/agronomy13051307 - 06 May 2023

Cited by 1 | Viewed by 1554

Abstract

Maize is the staple food of China, produced on 33.6% of the total arable land. In this context, an effective strategy to enhance maize yield is essential to meet the demand without expanding the cultivation areas. Maize yield can be increased by two [...] Read more.

Maize is the staple food of China, produced on 33.6% of the total arable land. In this context, an effective strategy to enhance maize yield is essential to meet the demand without expanding the cultivation areas. Maize yield can be increased by two key measures: plant-row space optimization and nutrient management. However, in traditional maize cultivation practices, fertilizer utilization by plants is inefficient. We therefore performed a manipulative experiment over two years (2018–2019), applying four treatments: (I) linear planting with nitrogen fertilization at 10 cm depth (CK), (II) linear planting with nitrogen fertilization at 20 cm depth (LD20), (III) zigzag planting with nitrogen fertilization at 10 cm depth (ZD10), and (IV) zigzag planting with nitrogen fertilization at 20 cm depth (ZD20). The aim of this study was to examine the influence of deep nitrogen fertilization and zigzag planting alone and in combination with root distribution, soil properties, canopy structures, and maize yield. Our results showed that all improved maize cultivating strategies (LD20, ZD10, and ZD20) increased the root length density up to 10–30 cm depth of soil layers compared to CK. Similarly, deep nitrogen fertilization increased the photosynthesis rate and leaf area duration after the silking stage. The leaf orientation value of the middle and upper canopies increased in zigzag planting compared to linear planting. It also increased the dry matter accumulation of medium leaves, leaf area duration, and dry matter accumulation after the silking stage. The maize yield was highly increased in ZD20 followed by ZD10, LD20, and the least by CK (traditional cultivating practices) in both years. Our study suggests that zigzag planting provides a higher yield than linear planting. Additionally, deep nitrogen fertilization in zigzag planting significantly increases the population resource utilization rate and yield by optimizing the root–canopy structures. Row spacing and nitrogen fertilization were found to be essential to enhance crop yield by influencing root growth and canopy efficiency. Full article

(This article belongs to the Special Issue Crop Yield Formation and Fertilization Management)

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13 pages, 3104 KiB

Open AccessArticle

Effect of Planting Density on Canopy Structure, Microenvironment, and Yields of Uniformly Sown Winter Wheat

by Feng Zhang, Dan Zhang, Lei Li, Zhiwen Zhang, Xueqi Liang, Qinglin Wen, Guodong Chen, Quanzhong Wu and Yunlong Zhai

Agronomy 2023, 13(3), 870; https://doi.org/10.3390/agronomy13030870 - 16 Mar 2023

Cited by 2 | Viewed by 1838

Abstract

A strong canopy structure is central to maximizing yield. The canopy microenvironment, which is related to crop growth and development, reflects changes in a crop’s microclimate. In this study, with the uniform sowing of winter wheat (Triticun aestivum L.), five planting densities [...] Read more.

A strong canopy structure is central to maximizing yield. The canopy microenvironment, which is related to crop growth and development, reflects changes in a crop’s microclimate. In this study, with the uniform sowing of winter wheat (Triticun aestivum L.), five planting densities (in 10⁴ plants·ha⁻¹: 123, 156, 204, 278, and 400) were established to examine how the planting density affected filling stage spikes, canopy structures, microenvironments, yields, and yield components. The large-spike Xindong 50 and multi-spike Sangtamu 4 varieties were used. The experiment was conducted over 263 days in the Xinjiang province, in a warm continental arid desert-type climate, with low precipitation. The study aimed to determine the optimal parameters for cultivation on limited land and improve the production potential. For both varieties, from anthesis to filling, increases in planting density were associated with a rapid reduction in the leaf area index of the lower and middle parts of the leaves. Canopy temperature and canopy CO₂ concentration also decreased, whereas relative humidity increased. The number of grains per spike and the thousand-grain weight of both varieties decreased with increased planting density. Yields were maximized at densities of 278 × 10⁴ and 156 × 10⁴ plants·ha⁻¹ for the large- and multi-spike varieties, respectively, indicating that uniform sowing improves plant uniformity, and adjusting planting density optimizes canopy structure and microenvironment. Our study provides valuable data for optimizing planting densities to ensure high yields. Full article

(This article belongs to the Special Issue Crop Yield Formation and Fertilization Management)

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15 pages, 11709 KiB

Open AccessArticle

Effect of Planting Patterns and Seeding Rate on Dryland Wheat Yield Formation and Water Use Efficiency on the Loess Plateau, China

by Jingjing Zhang, Junyi Mu, Yanan Hu, Aixia Ren, Bin Lei, Pengcheng Ding, Linghong Li, Min Sun and Zhiqiang Gao

Agronomy 2023, 13(3), 851; https://doi.org/10.3390/agronomy13030851 - 14 Mar 2023

Cited by 3 | Viewed by 1402

Abstract

Dryland winter wheat (Triticum aestivum L.) production plays an extremely important role in the southeast of the Loess Plateau. Planting patterns have great influence on improving soil water storage and yield, and should be matched with different seeding rates. In order to [...] Read more.

Dryland winter wheat (Triticum aestivum L.) production plays an extremely important role in the southeast of the Loess Plateau. Planting patterns have great influence on improving soil water storage and yield, and should be matched with different seeding rates. In order to assess the effect of different sowing methods on the drought resistance and stable yield of dryland wheat, a field experiment was conducted in Wenxi County Dryland Wheat Experimental Base in Shanxi Province, China. In the current study, the effects of three planting techniques (drilling sowing, furrow sowing, and film-mulched sowing) and four seeding rates (150, 225, 300, and 375 kg ha⁻¹) were examined on water storage, dry matter formation, yield, and water use efficiency (WUE). The results showed that furrow sowing (FS) and film-mulched sowing (FM) treatments increased soil water storage in the 0–300 cm soil layer at overwintering and jointing stages. In addition, FS and FM increased soil water consumption in the 0–300 cm soil layer from overwintering to maturity of wheat. Furthermore, FS and FM significantly increased the dry matter accumulation from the overwintering to the mature stage, promoted its accumulation in vegetative organs and translocation to grains after anthesis, viz., increased yield by 6.2% and 7.9%, and WUE by 4.6% and 5.3%, respectively, as compared with those of the drilling sowing (DS) treatments. Pearson’s correlation analysis showed that grain yield had a significantly positive correlation with soil water storage at overwintering and jointing. Moreover, grain yield was significantly positively correlated with soil water consumption in the 0–300 cm soil layer from jointing to maturity. Additionally, the seeding rate of 150 kg ha⁻¹ with FS could obtain higher WUE and grain yield. Therefore, it is strongly recommended that the seeding rate of 150 kg ha⁻¹ is used with FS to improve the grain yield and WUE of dryland agricultural systems in China. Full article

(This article belongs to the Special Issue Crop Yield Formation and Fertilization Management)

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21 pages, 4375 KiB

Open AccessArticle

Effects of Carbon-Based Fertilizer on Maize Root Morphology, Root Bleeding Rate and Components in Northeast China

by Xuerui Wang, Jian Li, Xiaofei Yang, Bin Wang, Wanrong Gu and Yubo Wang

Agronomy 2023, 13(3), 814; https://doi.org/10.3390/agronomy13030814 - 10 Mar 2023

Viewed by 1462

Abstract

Maize (Zea mays L.) is the largest grain crop in Heilongjiang Province. Carbon-based fertilizer is a mixed fertilizer produced by adding a certain proportion of chemical fertilizer with biochar as the loading substrate. In this study, the effects of carbon-based fertilizer on [...] Read more.

Maize (Zea mays L.) is the largest grain crop in Heilongjiang Province. Carbon-based fertilizer is a mixed fertilizer produced by adding a certain proportion of chemical fertilizer with biochar as the loading substrate. In this study, the effects of carbon-based fertilizer on the rhizosphere soil microenvironment and maize root system were discussed. Two maize varieties, Xianyu 335 and Jingke 968, were selected and six treatments were set as follows, including no fertilization (CK1), conventional fertilizer (CK2) and the amount of carbon-based fertilizer, which were 3 t/hm², 3.75 t/hm², 4.5 t/hm² and 5.25 t/hm², respectively. The results showed that carbon-based fertilizer increased the total root length, root volume, root area and root tip number of maize, and the root length, root volume, root area and root tip number of 4.5 t treatment performed better at all stages, which was significantly higher than that of chemical fertilizer. On 16 August (early filling stage), most of the root color changed from milky white to dark brown, the root clarity decreased, the number of roots decreased, the root volume significantly decreased and the root began to age, while the number and volume of roots treated with the carbon-based fertilizer remained stable, the root color was milky white, the morphological structure was clear and there was basically no aging. The carbon-based fertilizer treatment significantly increased the root biomass of 0–15 cm above the plant, 15–30 cm and 30–45 cm between the plants and 0–15 cm between the ridges, forming a wide and deep high-yield root system. The carbon-based fertilizer significantly increased the bleeding rate. On 8 July (jointing stage), Xianyu 335 and Jingke 968 reached the maximum value at the 3 t and 3.75 t treatments, respectively. The carbon-based fertilizer treatment had no significant effect on the amino acid content, but significantly increased the amino acid transport rate on 8 July (jointing stage) and 16 August (early filling stage). The transport rate of inorganic phosphorus gradually decreased with the advancement of the growth process. On 8 July (jointing stage), the ammonium nitrogen content and transport rate of the two varieties reached the maximum value at the treatment of 4.5 t and 3.75 t, which was significantly higher than the treatment of chemical fertilizer and no fertilizer, and showed a gradual downward trend with the advancement of the growth process. The soluble sugar content was relatively low in the early stage and increased rapidly on 4 September (waxy ripening stage). Both varieties reached the maximum value at 4.5 t treatment, and the transport rate reached the maximum value at 3.75 t treatment, which was significantly higher than that of the chemical fertilizer treatment. In conclusion, the carbon-based fertilizer significantly increased the yield of maize, and the yield of maize under the 4.5 t treatment reached the maximum, which was 15.02% and 18.24% higher than that of the chemical fertilizer treatment, respectively. Full article

(This article belongs to the Special Issue Crop Yield Formation and Fertilization Management)

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17 pages, 2350 KiB

Open AccessArticle

Proper Biochar Increases Maize Fine Roots and Yield via Altering Rhizosphere Bacterial Communities under Plastic Film Mulching

by Yanghui Sui, Yanbo Wang, Wanxin Xiao, Cheng Chang, Shuping Zhang and Haiyan Zhao

Agronomy 2023, 13(1), 60; https://doi.org/10.3390/agronomy13010060 - 24 Dec 2022

Cited by 1 | Viewed by 1144

Abstract

Biochar amendment is considered a sustainable agricultural strategy to improve crop yields. However, information on grain yield, fine roots and in relation to rhizosphere microbial communities in maize under plastic film mulching is very limited. Herein, biochar applied every 2 years (8.4 t [...] Read more.

Biochar amendment is considered a sustainable agricultural strategy to improve crop yields. However, information on grain yield, fine roots and in relation to rhizosphere microbial communities in maize under plastic film mulching is very limited. Herein, biochar applied every 2 years (8.4 t ha⁻¹, B1) and biochar applied every 5 years (21 t ha⁻¹, B2) combined with nitrogen (225 kg ha⁻¹), or nitrogen alone, were tested in a field experiment. The results showed that a biochar–fertilizer application significantly decreased the root length at the V9 stage, but biochar applied every 5 years significantly maintained the root length at the R6 stage. Biochar–fertilizer application increased grain yield under the B1 treatment while slightly decreasing under the B2 treatment. The rhizosphere of maize was preferentially colonized by Proteobacteria, Firmicutes, Sphingomonas, and Bradyrhizobium. Dominant phyla including Proteobacteria were enriched in bulk soils, while Bacteroidetes and Firmicutes were depleted in rhizosphere and bulk soils under the biochar–fertilizer application. Changes in root morphology and soil properties were responsible for bacterial community structure in response to different biochar applications. Thus, we concluded that the differential responses of maize yield and root attributes might be related to the specific biochar dose-specific effects on soil microbiome diversity. Full article

(This article belongs to the Special Issue Crop Yield Formation and Fertilization Management)

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19 pages, 6889 KiB

Open AccessArticle

Effect of Chemical Fertilizer Application on Maize Production in China over the Past 15 Years: A Meta-Analysis

by Fanlei Kong, Yawei Wu, Shilei Cui, Xinglong Wang, Gui Wei, Qinlin Liu, Tianqiong Lan, Fan Liu, Bo Zhao, Dongju Feng and Jichao Yuan

Agronomy 2022, 12(12), 3005; https://doi.org/10.3390/agronomy12123005 - 29 Nov 2022

Cited by 3 | Viewed by 3613

Abstract

Although there are many new types of environmentally friendly fertilizers that can improve maize yield, chemical fertilizers are the most widespread type of fertilizer used in the agricultural sector of China due to their low cost and ease of application. However, the misuse [...] Read more.

Although there are many new types of environmentally friendly fertilizers that can improve maize yield, chemical fertilizers are the most widespread type of fertilizer used in the agricultural sector of China due to their low cost and ease of application. However, the misuse of chemical fertilizers could lead to environmental problems, such as the massive emission of greenhouse gases (GHG). Therefore, it is important to determine how fertilizer-use efficiency (FUE) could be improved to stabilize or increase maize yield while reducing GHG emissions. In this study, we collected 6618 date records which include three datasets (for N, P, and K) from five maize-growing regions in China from 2005 to 2018, and performed a meta-analysis on the effects of N, K, and P fertilization levels on maize yield, partial factor productivity (PFP), agronomic efficiency (AE), and the carbon footprint of maize production. Additionally, scenario analyses were performed to estimate optimal fertilizer application rates for stabilizing or increasing maize yield while reducing GHG emissions. It was shown that FUE and maize yield responses to fertilization level varied in different regions. Compared to the past, the maize production of China has improved significantly in terms of FUE and its carbon footprint in recent years. Because of improvements in maize cultivars and cultivation technologies, it is possible to decrease N, P, and K application rates and reduce per unit area carbon footprint of maize, without compromising yield. In the future, N fertilization should be reduced by 10% from current levels, and the application of P and K fertilizers should be increased or decreased depending on the conditions of each maize-growing region. Thus, it should be possible to stabilize or even increase yields and reduce GHG emissions of maize production, thereby achieving green and efficient development. Full article

(This article belongs to the Special Issue Crop Yield Formation and Fertilization Management)

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22 pages, 2834 KiB

Open AccessArticle

Photophysiological Mechanism of Dense Planting to Increase the Grain Yield of Intercropped Maize with Nitrogen-Reduction Application in Arid Conditions

by Hong Fan, Wen Yin, Cai Zhao, Aizhong Yu, Zhilong Fan, Falong Hu, Jindan Zhang and Qiang Chai

Agronomy 2022, 12(12), 2994; https://doi.org/10.3390/agronomy12122994 - 28 Nov 2022

Cited by 2 | Viewed by 1135

Abstract

Leaf photophysiological characteristics are the main indexes that determine crop yield formation. However, it remains unclear whether photosynthesis is systematically regulated via the cropping pattern and nitrogen supply when maize crops are planted with a high density. So, a field experiment that had [...] Read more.

Leaf photophysiological characteristics are the main indexes that determine crop yield formation. However, it remains unclear whether photosynthesis is systematically regulated via the cropping pattern and nitrogen supply when maize crops are planted with a high density. So, a field experiment that had a three-factor split-plot arrangement of treatments was conducted from 2020 to 2021. The main plot was two cropping patterns that included the sole cropping of maize and wheat–maize intercropping. The split plot had two nitrogen application rates: a traditional nitrogen application rate (N2, 360 kg ha⁻¹) and one reduced by 25% (N1, 270 kg ha⁻¹) for maize. The split–split plot had three planting densities: a traditional density (M1, 78,000 plant ha⁻¹), a medium density (M2, 10,400 plant ha⁻¹), and a high density (M3, 129,000 plant ha⁻¹) for sole maize; the corresponding densities of intercropped maize were 45,000, 60,000, and 75,000 plant ha⁻¹, respectively. The grain yield, the photosynthetic traits, and chlorophyll a fluorescence of the maize were assessed. The results showed that a 25% nitrogen reduction and dense planting had a negative impact on the individual maize’s photosynthesis. However, intercropping could alleviate these drawbacks. When the maize was grown in the intercropping system at a lower nitrogen level and a medium planting density (IN1M2), the photosynthetic traits were better or similar to those of the traditional treatment (SN2M1) at the reproductive growth stage. Moreover, IN1M2 improved the light energy distribution among photochemistry, photo-protective and heat dissipation process of maize compared with SN2M1. A grey relation analysis demonstrated that the Pn and Tr of the individual maize played the most significant role in the group’s productivity. Thus, the IN1M2 treatment achieved the highest grain yield and can be recommended as a feasible agronomic practice in oasis-irrigated regions. Full article

(This article belongs to the Special Issue Crop Yield Formation and Fertilization Management)

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20 pages, 3845 KiB

Open AccessArticle

Green Manure Return Strategies to Improve Soil Properties and Spring Maize Productivity under Nitrogen Reduction in the North China Plain

by Gang Su, Rui Zhao, Yizhen Wang, Yong’an Yang, Xidong Wu, Jinlong Wang and Junzhu Ge

Agronomy 2022, 12(11), 2734; https://doi.org/10.3390/agronomy12112734 - 04 Nov 2022

Cited by 3 | Viewed by 1492

Abstract

In order to study the effect of green manure return for stabilized spring maize (Zea mays L.) grain yield (GY) we reduced nitrogen fertilizer input by regulation and examined effects on soil nutrients, enzyme activity, and fungal communities. This two-year field experiment [...] Read more.

In order to study the effect of green manure return for stabilized spring maize (Zea mays L.) grain yield (GY) we reduced nitrogen fertilizer input by regulation and examined effects on soil nutrients, enzyme activity, and fungal communities. This two-year field experiment was conducted in the North China Plain. The field experiment was undertaken with a split-plot design; the primary plots were winter fallow (WF) and green manure (GM), and the split-plots were five N application rates of 0 (N0), 189 (N189), 216 (N216), 243 (N243), and 270 (N270) kg ha⁻¹. The results showed that, spring maize GY under GM treatments (GY_GM) were significantly increased by 5.38–11.68% more than WF treatment (GY_WF), and GY_WF and GY_GM significantly increased by 35.9–91.5% and 80.1–135.5% across all N treatments. By linear-platform model analysis, spring maize under GM treatments obtained higher GY, reaching 1270.5–14,312.2 kg ha⁻¹ with optimized N application rate at 238–265 kg ha⁻¹, which resulted in a GY higher than WF (11,820.0 and 13,654.2 kg ha⁻¹) and N reduced 11.2% (238 vs. 268 kg ha⁻¹). GM treatment significantly increased soil organic carbon by 3.90–12.23% more than WF over all N application rates, and total nitrogen and available nitrogen were significantly increased by 3.79–15.76% and 4.87–17.29%, with total phosphorus and available phosphorus for GM higher than WF by 6.1–13.6% and 9.6–5.3%, respectively. However, there were lesser effects of GM on total potassium and available potassium. Compared to WF, soil catalase, sucrose, urease, and alkaline phosphatase activity were significantly increased by 6.2–16.4%, 5.8–48.1%, 3.3–21.5% and 11.5–82.3%, respectively, over all N application rates under GM over two years. GM increased Zygomycota and Basidiomycota relative abundances significantly, and reduced Thielavia, unclassified fungi, and Podospora relative abundances by 35.35%, 52.92% and 52.77% more than WF treatment, respectively. In summary, due to the GM return into fields, increased soil nutrients were available, which were positively affected by soil enzyme activity and fungal communities, and reduced nutrient requirements, and so the farmers could obtain a spring maize grain yield higher than 14,000 kg ha⁻¹ with a reduced 11.2% N application rate from 268 kg ha⁻¹ to 238 kg ha⁻¹ by sowing winter green manure for a long time period in the North China Plain. Full article

(This article belongs to the Special Issue Crop Yield Formation and Fertilization Management)

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14 pages, 3249 KiB

Open AccessFeature PaperArticle

Characterization of Root Morphology and Anatomical Structure of Spring Maize under Varying N Application Rates and Their Effects on Yield

by Xiangling Li, Rui Wang, Baoyuan Zhou, Xinbing Wang, Jian Wang, Ming Zhao and Congfeng Li

Agronomy 2022, 12(11), 2671; https://doi.org/10.3390/agronomy12112671 - 28 Oct 2022

Cited by 3 | Viewed by 1692

Abstract

Root morphology is an important factor determining nitrogen (N) uptake by plants, which might be affected by the extent of N application. The processes associated with root morphogenesis of spring maize in response to N application rates remain poorly understood. In this study, [...] Read more.

Root morphology is an important factor determining nitrogen (N) uptake by plants, which might be affected by the extent of N application. The processes associated with root morphogenesis of spring maize in response to N application rates remain poorly understood. In this study, both field and pot experiments were conducted to explore the effect of zero-N (N0), optimized-N (N180), and high-N (N360) on root morphology, anatomical structure, and N accumulation in spring maize. N application rates affected root length and surface area, and its endogenous hormone contents. The largest difference in total root length and surface area among the three N rates was found at the silking stage: the total root length and surface increased by 51.36% and 42.58% under N180 and by 7.8% and 30.14% under N360, respectively, compared with N0, and the root/shoot ratio and root bleeding sap significantly increased under N180 and N360 compared with N0. The auxin and jasmonic acid levels of roots under N180 and N360 were higher than N0. N application rates also affected root microstructure and ultrastructure. Compared with N0, the proportions of root aerating tissue under N180 and N360 were decreased by 32.42% and 11.92% at silking. The root tip cell structure was damaged under N0, and intact under N180 and N360. Moreover, the ¹⁵N allocation proportions to root and grain under N180 and N360 were increased compared to N0. Grain yields under N180 and N360 increased by 20.44% and 16.6% compared with N0, respectively. It can be concluded that optimized-N application decreased root aerated tissue and thus improved root length and root surface area through regulating auxin and jasmonic acid levels and affected N uptake and grain yield of N-efficient spring maize variety. Full article

(This article belongs to the Special Issue Crop Yield Formation and Fertilization Management)

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16 pages, 11347 KiB

Open AccessArticle

Effects of Planting Density, Levels, and Forms of Nitrogen Application on the Yield and Nitrogen Utilization of Wheat following Rice in East China

by Zhilin Xiao, Hanzhu Gu, Hao Wu, Wenjiang Jing, Kuanyu Zhu, Weiyang Zhang, Junfei Gu, Lijun Liu, Xiaoqing Qian, Zhiqin Wang, Jianchang Yang and Hao Zhang

Agronomy 2022, 12(11), 2607; https://doi.org/10.3390/agronomy12112607 - 23 Oct 2022

Cited by 4 | Viewed by 1514

Abstract

A major challenge is to achieve the goal of synergistically increasing grain yield and nitrogen use efficiency in wheat production. Many studies have focused on one aspect of cultivation such as fertilizer management, suitable planting density, and straw returning. However, there are few [...] Read more.

A major challenge is to achieve the goal of synergistically increasing grain yield and nitrogen use efficiency in wheat production. Many studies have focused on one aspect of cultivation such as fertilizer management, suitable planting density, and straw returning. However, there are few studies on the effect of integrated cultivation practices on yield and nitrogen absorption and utilization of wheat. A field experiment to investigate the characteristics was conducted across two years using Yangmai 16 and Yangmai 20 with five cultivation practices including nitrogen blank area (NB), local practices (LP), nitrogen reduction (NR), planting density reduction and nitrogen reduction (DN), and organic fertilizer (OF). As compared with LP, the DN treatment improved the yield (+4.54%), recovery efficiency of N fertilizer (+5.59%), N partial factor productivity (+15.28%), agronomic N use efficiency (+21.43%), physiological N use efficiency (+14.90%), and nitrogen harvest index (+6.45%). All previous indices were increased by 16.84%, 28.18%, 19.59%, 45.81%, 13.96%, and 3.37% under the OF treatment, as compared with LP. The DN and OF significantly improved nitrogen use efficiency, photosynthetic characteristics, dry matter accumulation, root total and active absorbing surface area, root oxidation activity, nitrogen accumulation, nitrogen harvest index, and nitrogen transportation in various organs. The results suggest that integrated cultivation practices are beneficial to achieve high yield and high nitrogen use efficiency through improving the agronomic performance and root physiological characteristics. Full article

(This article belongs to the Special Issue Crop Yield Formation and Fertilization Management)

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13 pages, 2826 KiB

Open AccessArticle

Reducing and Delaying Nitrogen Recommended by Leaf Critical SPAD Value Was More Suitable for Nitrogen Utilization of Spring Wheat under a New Type of Drip-Irrigated System

by Wenliang Wan, Yanhui Zhao, Jing Xu, Kaige Liu, Sihui Guan, Yaqian Chai, Hongxing Cui, Pei Wu and Ming Diao

Agronomy 2022, 12(10), 2331; https://doi.org/10.3390/agronomy12102331 - 28 Sep 2022

Cited by 4 | Viewed by 1369

Abstract

Timely and accurate judgment of the nitrogen nutritional status of crops is the key to develop an optimal nitrogen application strategy. However, the evaluation criteria of nitrogen nutrition and nitrogen application strategies at each growth stage of wheat are not clear for the [...] Read more.

Timely and accurate judgment of the nitrogen nutritional status of crops is the key to develop an optimal nitrogen application strategy. However, the evaluation criteria of nitrogen nutrition and nitrogen application strategies at each growth stage of wheat are not clear for the new type of drip-irrigated spring wheat system, TR6S (where one drip tube serves six rows of wheat, with a row spacing (RS) of 10 cm, inter-block space (IBS) of 25 cm and the lateral spacing (LS) of 80 cm, which achieved a lower drip-tube input and higher profit compared with the traditional planting system in Xinjiang). Therefore, we studied the recommendation mechanism of nitrogen fertilizer in different growth stages of wheat based on the critical SPAD values of leaves under TR6S. We set four nitrogen treatments (N1 (300 kg ha⁻¹), N2 (270 kg ha⁻¹), N3 (240 kg ha⁻¹) and N4 (0 kg ha⁻¹)) during two spring wheat growth seasons. The results revealed that the correlation coefficient (r²) between SPAD (soil plant analysis development) value and plant nitrogen content in the middle of first top leaf (L1-M) of wheat was higher than that in other leaf types and leaf positions under TR6S. A quadratic function relationship existed between a SPAD value of L1-M and grain yield. The critical SPAD values at the jointing, booting, anthesis, early milk, and late milk stages were 37.34, 39.40, 42.25, 45.57, and 35.91, respectively. In addition, through the establishment of the nitrogen application recommendation model for various wheat growth stages based on the critical SPAD value, the recommended optimal nitrogen application rates at jointing, booting, anthesis, early milk, and late milk stages were observed to be 69.4, 80.0, 90.8, 44.0, and 6.0 kg ha⁻¹, respectively. This recommended nitrogen application strategy exhibited a better parallel relationship with the nitrogen nutrition index (NNI) of each growth period than the conventional nitrogen application strategy. Therefore, it was more in line with the actual absorption and utilization of nitrogen in wheat of TR6S. In conclusion, the SPAD values of L1-M could be relatively more accurate to evaluate the nitrogen nutrition status of wheat. Compared to traditional nitrogen application strategy, reducing and delaying nitrogen application, recommended based on the leaf SPAD model, was more suitable for nitrogen utilization under TR6S. The results can be applied in other arid and semiarid regions. Full article

(This article belongs to the Special Issue Crop Yield Formation and Fertilization Management)

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