Amount Of Nitrogen Fertilizer Research Articles

Controlled-Release Nitrogen Mixed with Common Nitrogen Fertilizer Can Maintain High Yield of Rapeseed and Improve Nitrogen Utilization Efficiency.

Field experiments were conducted to study the effects of different proportions of controlled-release nitrogen fertilizer mixed with quick-acting nitrogen fertilizer on the yield and nitrogen utilization efficiency of direct-seeding rapeseed. Using a conventional nitrogen application rate of 180 kg ha-1 as a control, a total of 5 types of available nitrogen fertilizers and different proportions of controlled-release nitrogen fertilizers were mixed for fertilizer treatment. The proportion of available nitrogen fertilizer used was 135 kg ha-1, and the addition ratios of the five types of controlled-release nitrogen fertilizers were 0%, 30%, 50%, 70%, and 100%, respectively (i.e., the proportion of controlled-release nitrogen to the total nitrogen application amount). These ratios were represented as N135R0, N135R1, N135R2, N135R3, and N135R4, respectively. The results showed that there was no significant difference in the number of pods per plant, the number of seeds per pod, or the grain yield under the treatment of controlled-release nitrogen fertilizer mixed with quick-acting nitrogen fertilizer for proportions of 30-50% (N135R1~R3) when compared with the control, and a stable yield was achieved. Mixing controlled-release nitrogen fertilizer under reduced nitrogen application can significantly improve the apparent utilization rate of rapeseed nitrogen fertilizer, but it first increases and then decreases with the increase of the controlled-release nitrogen mixing ratio, reaching its highest under the N135R2 treatment. The agronomic utilization efficiency and partial productivity of nitrogen fertilizer first increased and then decreased with the increased proportion of controlled-release nitrogen, and both reached their highest utilization with the N135R2 treatment. The mixed treatment of controlled-release nitrogen did not affect soil urease activity, but significantly increased soil sucrase activity. The mixed treatment of controlled-release nitrogen also increased soil microbial biomass nitrogen and carbon content. Especially in the flowering stage, the soil microbial biomass nitrogen and carbon content was significantly higher under a controlled-release nitrogen mixing ratio of 30-50%. At the same time, it had a similar effect on soil inorganic nitrogen content. Therefore, a controlled-release nitrogen mixing treatment provided sufficient nitrogen for the key growth period of rapeseed. Under the condition of reducing the amount of nitrogen fertilizer by 25% based on the amount of nitrogen fertilizer applied to conventional rapeseed, the application of controlled-release urea mixed with common nitrogen fertilizer mixed at a ratio of 30-50% can be an effective way to maintain grain yield levels and improve nitrogen utilization efficiency.

Pesticide-free arable cropping systems: performances, learnings, and technical lock-ins from a French long-term field trial

To ensure regular and high yields, current agriculture is based on intensive use of pesticides and fertilizers, which are detrimental to the environment and human health. Moreover, as pest resistance to pesticides increases, and more and more pesticides are taken off the market, national and European policies are becoming powerful drivers to deliver pesticide-free farming systems. Whereas numerous studies have compared organic versus conventional systems, our study assessed, for the first time, the performances of a pesticide-free arable cropping system (No-Pesticide), using synthetic fertilizers, specifically designed to produce high yields and meet environmental goals. This system was compared with an input-based cropping system designed with the same environmental targets (PHEP: productive with high environmental performances) in an 11-year field trial in France (Paris Basin). Banning pesticides did not result in a significant average yield gap (in GJ.ha−1.year−1 or in kg N.ha−1.year−1) calculated over the crop sequence. Yet, some crops’ yields significantly decreased, due either to pest damages, or to limited nitrogen nutrition. In the No-Pesticide system, the mycotoxin content of cereal grains was lower than the regulatory threshold, and the average wheat protein content was higher than the required standard for baking. Indirect energy consumption, total greenhouse gas emissions, number of technical operations, nitrogen fertilizer amounts, and treatment frequency indexes were significantly lower compared to the PHEP system. Conversely, results showed significantly higher direct energy consumption, direct greenhouse gas emissions, and number of work hours for weed control. We identify highly effective agricultural strategies to avoid pesticide use (e.g., widely diverse and long crop sequence; introduction of hemp) and pinpoint several technical lock-ins hampering steady production in pesticide-free systems. We argue that more experiments should be undertaken to deliver technical knowledge for managing major or orphan species within pesticide-free systems, and to provide supplementary results, including economic and social performances.

Effects of Different Nitrogen Application Rates on Root Growth and Distribution of Fine Root Length across Diameter Classes of Wolfberry (Lycium barbarum L.)

The optimized cultivation process of wolfberry (Lycium barbarum L.) to maintain a consistently high and stable yield relies on the prolonged use of significant amounts of nitrogen fertilizers. However, this practice leads to increased production costs and various issues, such as soil pollution and compaction. To address these concerns, a three-year field trial was conducted involving different nitrogen application rates: N1 (20% nitrogen (N) reduction, 540 kg·hm−2), N2 (medium N, 675 kg·hm−2), and N3 (20% nitrogen increase, 810 kg·hm−2). The results showed that the inter-annual growth and development of wolfberry roots had two rapid growth peaks. In comparison with the N3 treatment, the root morphological characteristics index increased significantly under the N1 and N2 treatments. Among the different diameter classes, the most significant increase in fine root length, with an average diameter between 0.4 and 0.8 mm, occurred under the N1, N2, and N3 treatments, accounting for 50.6%, 50.92%, and 47.72% of the total annual growth of root length increments, respectively. Concerning the distribution of fine roots, the active layer depth extended under the N2 treatment suggesting that medium nitrogen application favored the longitudinal extension of fine roots. Leaf nitrogen content and the chlorophyll meter values (SPAD values) in the upper part of the plant, at the tip of shoots/branches, were the most sensitive indicators to changes in nitrogen application rates. These values increased significantly with higher nitrogen application amounts. Similarly, the contents of total sugar, betaine, and β-carotene increased with increasing nitrogen application rates, while the contents of Lycium barbarum polysaccharides (LBPs) and total flavonoids decreased. Finally, based on a comprehensive principal component evaluation, the rankings for root growth and plant development under various nitrogen application treatments were as follows: N2 (1.891) > N1 (0.002) > N3 (−1.894). The results showed that both the aboveground and belowground growth and development of wolfberry plants were most optimized under the N2 treatment. These findings provide a foundational reference for constructing good root morphology of wolfberry through cultivation practices such as nitrogen fertilizer management.

Mapping the ratio of agricultural inputs to yields reveals areas with potentially less sustainable farming

Fertilisers and pesticides are major sources of the environmental harm that results from farming, yet it remains difficult to target reductions in their impacts without compromising food production. We suggest that calculating the ratio of agrochemical inputs to yield can provide an indication of the potential sustainability of farmland, with those areas that have high input relative to yield being considered as less sustainable. Here we design an approach to characterise such Input to Yield Ratios (IYR) for four inputs that can be plausibly linked to environmental impacts: the cumulative risk resulting from pesticide exposure for honeybees and for earthworms, and the amount of nitrogen or phosphorus fertiliser applied per unit area. We capitalise on novel national-scale data to assess IYR for wheat farming across all of England. High-resolution spatial patterns of IYR differed among the four inputs, but hotspots, where all four IYRs were high, were in key agricultural regions not usually characterised as having low suitability for cropping. By scaling the magnitude of each input against crop yield, the IYR does not penalise areas of high yield with higher inputs (important for food production), or areas with low yields but which are achieved with low inputs (important as low impact areas). Instead, the IYR provides a globally applicable framework for evaluating the broad patterns of trade-offs between production and environmental risk, as an indicator of the potential for harm, over large scales. Its use can thus inform targeting to improve agricultural sustainability, or where one might switch to other land uses such as ecosystem restoration.

Using post‐season tissue nitrogen concentrations to predict adequacy of in‐season nitrogen management

AbstractHigh‐yielding mechanized rice production requires large amounts of nitrogen (N) fertilizer, which can be particularly costly to producers when applied in excess. The development of a tissue test to detect overapplication of N to rice is needed. Nitrogen response trials arranged in a randomized complete block design were established to identify a critical concentration threshold for a tissue test to detect excess N availability. Rice stalk samples were collected from 0 to 20 cm above the soil within 5 days of harvest and analyzed for NO3−‐N concentration. Two models were fit to the data to represent rice grain yield as a function of N concentration: the linear plateau model and the quadratic plateau model. The data were well represented by both models; however, the linear plateau model more accurately described the data with a normalized root mean square error of 0.128 for linear plateau and 0.131 for quadratic plateau and a significant F‐test (p < 0.0001). The join point of the linear response region and the plateau region of the model serves as a critical value that separates the responsive (N deficient) and non‐responsive (N optimum or excessive) regions. The 95% confidence interval of the join point (2.1 mg NO3−‐N kg−1) was selected as a practical, agronomic critical concentration threshold to reduce false positive errors. The data presented here further supports the use of a post‐season tissue test in rice to detect overfertilization and establish a critical concentration threshold for this tissue test.

Screening of high-efficiency nitrogen-fixing bacteria from the traditional Chinese medicine plant Astragalus mongolicus and its effect on plant growth promotion and bacterial communities in the rhizosphere

BackgroundAstragalus mongolicus Bunge is used in traditional Chinese medicine and is thus cultivated in bulk. The cultivation of A. mongolicus requires a large amount of nitrogen fertilizer, increasing the planting cost of medicinal materials and polluting the environment. Isolation and screening of plant growth-promoting rhizobacteria (PGPR) and exploring the nitrogen fixation potential of A. mongolicus rhizosphere microorganisms would effectively reduce the production cost of A. mongolicus.ResultsThis study used A. mongolicus roots and rhizosphere soil samples from Longxi County of Gansu Province, Jingle County, and Hunyuan County of Shanxi Province, China, to isolate and identify nitrogen-fixing bacteria. Through nitrogen fixation efficiency test, single strain inoculation test, and plant growth-promoting characteristics, three strains, Bacillus sp. J1, Arthrobacter sp. J2, and Bacillus sp. G4 were selected from 86 strains of potential nitrogen-fixing bacteria, which were the most effective in promoting the A. mongolicus growth and increasing the nitrogen, phosphorus, and potassium content in plants. The antagonistic test showed that these bacteria could grow smoothly under the co-culture conditions. The J1, J2, and G4 strains were used in a mixed inoculum and found to enhance the biomass of A. mongolicus plants and the accumulation of the main medicinal components in the field experiment. Mixed bacterial agent inoculation also increased bacterial diversity and changed the structure of the bacterial community in rhizosphere soil. Meanwhile, the relative abundance of Proteobacteria increased significantly after inoculation, suggesting that Proteobacteria play an important role in plant growth promotion.ConclusionsThese findings indicate that specific and efficient PGPRs have a significant promoting effect on the growth of A. mongolicus, while also having a positive impact on the structure of the host rhizosphere bacteria community. This study provides a basis for developing a nitrogen-fixing bacterial fertilizer and improving the ecological planting efficiency of A. mongolicus.

The responses of genotypes with contrasting NUtE to exogenous ABA during the flowering stage in Brassica napus

A large amount of nitrogen (N) fertilizer is applied to maintain a stable yield because of the low N utilization efficiency (NUtE) in rapeseed (Brassica napus L.), which increases production costs and has a negative impact on the environment. Abscisic acid (ABA) has been reported to have crosstalk with nitrate. In this study, exogenous ABA treatment and RNA-seq were used to explore the response patterns of rapeseed with contrasting NUtE to ABA signals. Our results showed that ABA application on leaf promoted the N allocation from vegetative organs to grain and increased the number of seeds per silique, grain yield, N harvest index (NHI), and the NUtE in N-efficient rapeseed. Transcriptome analysis showed the DEGs were mainly enriched in N metabolism, ABC transporters, and MAPK signaling pathways. Among them, the Glutamate dehydrogenase (GS) genes and the Glutamine synthetase gene were more highly expressed in the N-efficient genotype leaf than the N-inefficient genotype after ABA treatment. In contrast, the opposite expression level was observed in seven genes, including nitrate transporter 2.1, Nitrate Reductase genes, and GS genes in the root. In conclusion, the shoot and root of rapeseed may have different response mechanisms to ABA stimulation, and N-efficient rapeseed is more sensitive to ABA treatment, which may be one of the reasons for the difference in NUtE

Life Cycle Assessment of Winter Wheat Production Using Precision and Conventional Seeding Technologies

Sustainable and responsible agricultural production is one of the keys to keeping people, animals, soil, and the environment healthy. Precision seeding technologies for winter wheat, exploiting the variability of soil properties and adapting the technological processes of variable rate seeding and variable seeding depths, are essential not only to improving plant productivity and economic benefits but also to cleaner agricultural production. This work aimed to carry out a life cycle assessment (LCA) of winter wheat production and determine the environmental impact of different precision seeding technologies in terms of individual impact categories compared to conventional seeding technology. Experimental studies were carried out between 2020 and 2022 using conventional uniform seeding rate (URS) and several precision seeding technologies: in the first year—VRS for variable seeding rate and VRS + VRF for variable seeding rate and fertilizer rate, and in the second year—VRS and VRSD for variable seeding rate and variable depth, and VRSD + VRF for variable seeding rate, variable depth, and variable fertilizer rate. The results obtained for winter wheat grain yield showed that the effect of precision seeding technology on the increase of grain yield was not significant compared to the URS. A greater influence on grain yield was found in individual soil management zones, especially in the zone with the worst soil fertility. The LCA did not show any significant differences between precision seeding technology and conventional technology in any of the environmental impact categories. The GWP values (0.200–0.236 kg CO2eq kg−1) were most dependent on grain yield, as precision seeding technology had small changes in the amount of inputs (seeds and fertilizers), while all other technological operations were the same as under the URS technology. The amounts of phosphorus and potassium fertilizers decreased by 1.4 and 7.9%, respectively, and the amounts of winter wheat seeds and nitrogen fertilizers increased by 4.1 and 5.4%, respectively, compared to the URS.

Electrical signal of pepper during cropping period affected by different amount of fertilizer

Precision agriculture requires supply of adequate amount of fertilizer application to increase crop yield and prevent environmental contamination. Objective of the study was to evaluate response of pepper under different fertigation method and amount using plant induced electrical signal (PIES) for precision agriculture. Pepper was fertigated 10 times with recommended additional nitrogen fertilizer and set as a control. Low fertilizer treatment did not receive additional urea and high fertilizer received three times higher amount of nitrogen fertilizer. Conventional treatment was fertigated as basal fertilizer and once with additional fertilizer. The PIES decreased during vegetative stage and remained constant at reproductive stage because of reduced nutrient and water uptake. The PIES showed positive relationship with soil NH4+, NO3−, stem NO3− and leaf N, which resulted in highest PIES value during reproductive stage in high fertilizer treated pepper. Plant growth parameters were also related with the PIES although yield was not affected by different fertilizer treatment.

Effect of straw return on soil respiration in dryland agroecosystem of China: A meta-analysis

In agroecosystems, straw return is considered an important agricultural management practice influencing soil respiration. However, the impact of straw return on soil respiration is equivocal and the underlying mechanisms underpinning any responses remain unclear. To address this, we synthesized 86 recently published papers on dryland agroecosystems in China, which comprise approximately 74% of the agricultural land area, using a meta-analysis approach and explored the influence of straw return on soil respiration and the underlying mechanisms involved. Straw return resulted in a 13.5% increase in soil respiration, a 9.4% increase in soil moisture, a 10.4% increase in crop yield, a 18.9% increase in SOC (soil organic carbon), and a 2.6% decrease in soil temperature. Compared to conventional tillage without straw return treatment, the increase in soil respiration in response to straw return was closely related to modifications in soil temperature, soil moisture, SOC, and crop yield (P < 0.05). The contribution of the different drivers to increases in soil respiration in response to straw return showed a trend of crop yield > soil temperature > SOC > soil moisture. In addition, straw mulching, crop planting system, tillage method, and fertilization modified the effect of straw return on soil respiration. The increase in soil respiration was less when straw was used as a mulch (12.9%), compared to when it was incorporated into the soil (18.8%). The cropping system also influenced the effect of straw return on soil respiration and was increased by 21.1% in inter-crops, and by 17.3% and 11.0% in monocultures and rotations treatments, respectively. Our results also showed that the effect of straw return on soil respiration was larger in deep tillage treatments than in shallow tillage treatments (26.9% vs.18.7%). In addition, the effect of straw return on soil respiration was also larger in fertilized treatment compared to unfertilized one (12.7% vs. 0.5%). However, this depended on the amount of nitrogen fertilizer applied rates and was higher (14.8%) with low (<300 kg ha−1) application rates compared to high (≧300 kg ha−1) ones (2.5%). Therefore, in dryland agroecosystems in China, biological factors, especially those related to crop yield, may be a more important factor regulating the effect of straw return on soil respiration. However, straw mulching, crop planting system, tillage method, and fertilization can modify the effect of straw return on soil respiration.

Unveiling the combined effect of nano fertilizers and conventional fertilizers on crop productivity, profitability, and soil well-being

It is widely accepted that deficiency of macro (nitrogen) and micronutrients (zinc, copper etc.) affects the plant growth and development which cause a significant threat to crop production and food security. The Indian Farmers Fertilizer Cooperative (IFFCO) developed nano-urea (nano-N), nano-zinc (nano-Zn), and nano-copper (nano-Cu) liquid fertilizer formulations to enhance the crop yields, simultaneously addressing the nutrient deficiency, without causing toxicity. Therefore, this study was formulated to evaluate the effectiveness of nano-N (nano-urea), nano-Zn, and nano-Cu at varying N levels [0, 50, 75, and 100% of the recommended rates of nitrogen (RRN)] on maize-wheat and pearl millet-mustard systems during 2019–20 and 2020–21. The results exhibited that the application of nano-N + nano-Zn with 100% RRN exhibited significantly higher grain yields in maize (66.2–68.8%), wheat (62.6–61.9%), pearl millet (57.1–65.4%), and mustard (47.2–69.0%), respectively, over absolute control plots and combinations of three nano-fertilizers like nano-N + nano-Zn + nano-Cu applied plots. This was mainly attributed to the higher N and Zn uptake by the crops. However, 75% RRN with nano-N + nano-Zn also produced comparable yields. Thus, applying nano-N and nano-Zn via foliar applications, in conjunction with conventional urea, has the potential to reduce the required nitrogen fertilizer amount by up to 25%, while simultaneously maintaining equivalent yield levels. Similarly, 100% RRN and 75% RRN + nano-N + nano-Zn registered comparable profitability, soil mineral N, dehydrogenase activity (DHA), and soil microbial biomass carbon (SMBC), during both the study years. However, further research and field trials on nano fertilizers alone or in combination with conventional fertilizers are essential to fully unlock its benefits and ascertain its long-term effects which may offer a pathway to more efficient and eco-friendly crop nourishment.

Response of Quality and Yield of Foxtail Millet to Nitrogen and Zinc Application

The effect of nitrogen and zinc treatment on quality and yield was studied to provide a theoretical basis for generating high-quality and high-yielding foxtail millet. In the years 2021–2022, ‘Jingu 21’ was utilized as the test material in a split-plot design. The main plot was subjected to nitrogen treatment, while the sub-plot was treated with zinc. An arrangement of random blocks was employed. Four levels of nitrogen application (0 kg/hm2, 120 kg/hm2, 180 kg/hm2, 240 kg/hm2) and three levels of zinc application (20 mg/L, 40 mg/L, 80 mg/L foliar spraying) were set, resulting in a total of twelve treatments. Each treatment was replicated three times, with each plot covering an area of 15 m2. (1) The findings indicated that the contents of crude fat and crude protein in foxtail millet increased initially and then decreased with the increase in nitrogen application concentration. Additionally, the protein components were found to be in the following order: gliadin &gt; albumin &gt; glutenin &gt; globulin. (2) Adding an appropriate amount of nitrogen fertilizer under the same zinc level promoted the contents of amylose, total carotenoids, and flavonoids in millet to some extent. Over the course of two years, the content of flavonoids in millet was highest when treated with N180Zn40 (nitrogen 180 kg/hm2, zinc 40 mg/L), showing an increase of 50.14% and 58.67%, respectively, compared to the treatment of applying zinc fertilizer alone at the same zinc level. (3) The phytic acid content and phytic acid/zinc molar ratio exhibited a pattern of initially decreasing and then increasing with the rise in nitrogen and zinc concentrations. (4) The application of zinc fertilizer and increased nitrogen fertilizer for two consecutive years had a significant impact on the yield of millet. Additionally, the application of zinc fertilizer had a highly significant effect on both the ear weights and thousand-kernel weights of millet (p &lt; 0.001). The results demonstrated a positive synergistic effect when nitrogen fertilizer and zinc fertilizer were applied together. This combination significantly improved millet yield and thousand-kernel weights, enhanced the nutritional quality, and increased the content of functional components. Additionally, it also improved the availability of zinc.

CONTRIBUTION OF IMPROVING NITROGEN USE EFFICIENCY TO AGRICULTURAL ECONOMICS IN EUROPE

Contribution of improving nitrogen use efficiency (NUE) to the European agricultural economy was evaluated for the year 2020 for all European countries. For this purpose, the economic benefit of using fewer nitrogenous mineral fertilizers has been revealed for a 5% improvement in NUE and attaining maximum NUE. The Eurostat/OECD gross nutrient balance methodology was used to calculate NUE values and the amount of nitrogenous mineral fertilizer that will be used less when the NUE is improved. The results showed that improving NUE would result in significant economic benefits; even if NUE was improved by 20%, the benefit would be greater than half the cost of purchasing nitrogenous mineral fertilizers. Yearly economic benefits from purchasing nitrogenous mineral fertilizers in Europe would be 2.6 and 10.7 billion euros for a 5% improvement in NUE and a maximum NUE in 2020, respectively. According to the findings of the study, increasing NUE by reducing N mineral fertilizer use would result in significant economic benefits. Key Words: Nitrogen Use Efficiency, Nitrogenous Mineral Fertilizers, Economic Benefit, Agricultural Economics, Europe

Intercropping Peanut under Forests Can Reduce Soil N2O Emissions in Karst Desertification Control

In the process of vegetation restoration for karst desertification management, the lack of scientific and rational intercropping technology and the blind application of large amounts of nitrogen fertilizer have made the soil the main source of atmospheric N2O in this region. How soil N2O emissions vary under different intercropping modes is a scientific question worthy of study. This study took a three-year-old loquat (Eribotrya japonica L.) artificial forest in the karst plateau canyon as the experimental site and designed loquat intercropping with peanut, corn, and sweet potato (Ipomoeabatatas (L.) Lam.) as well as non-intercropping to analyze the differences in soil physicochemical properties and greenhouse gas emissions under different intercropping patterns. The results showed that intercropping with peanut significantly increased loquat yield, soil moisture, temperature, SOC, MBC, TN, and MBN content. The emissions of N2O and CO2were mainly positively correlated with soil moisture and temperature, while CH4 showed a negative correlation with soil moisture and soil temperature. The soil absorbed CH4 in the control of karst desertification. Karst area soils exhibited higher N2O emissions. Intercropping patterns significantly influenced soil N2O emissions, with N2O-N cumulative emissions ranging from 5.28 to 8.13 kg·hm−2 under different intercropping conditions. The lowest N2O-N cumulative emissions were observed for peanut intercropped under the forest. The peak N2O emission occurred in April 2022, which may be attributed to the higher rainfall and soil moisture during that month. Intercropping peanut with loquat significantly reduced the global warming potential. Therefore, intercropping peanut in young forests can improve soil water and fertilizer conditions, reduce soil N2O emissions and global warming potential, and serve as a nitrogen fixation and emission reduction technique suitable for karst desertification areas.

Simulation of pepper (Capsicum annuum L.) growth stages under different nitrogen fertiliser levels based on three models

ABSTRACT The pepper variety ‘Sanying’ was treated with different nitrogen levels (0.36, 0.72, 1.08, 1.44, 1.80, 2.16, 2.52, 2.88 g/basin) in 2022. The onset, end dates, and the meteorological data of the environment of each growth period were recorded. Simulation models of the effect of nitrogen levels on the growth period of pepper were constructed with physiological development time (PDT), product of thermal effectiveness and photosynthetically active radiation (PAR) (TEP), and growing degree days (GDD) as indices using experimental data from March to September. The models were fitted and verified with experimental data from April to October. The results showed that with the increase of the amount of nitrogen fertiliser, the growth process of pepper showed a significantly delayed trend. The root mean squared errors of the fitting values and observed values during the flowering stage, fruit setting stage, and harvesting stage of peppers were 1.02 days, 1.05 days, and 1.27 days, respectively. The relative errors were 0.71%, 0.88%, and 0.95%, and the coefficients of determination (R 2) were 0.97, 0.96, and 0.94, respectively. Therefore, the PDT model is the optimal model with the highest simulation accuracy to simulate the pepper phenological stage under different nitrogen levels.

QTL Mapping and Functional Identification of Candidate Genes Regulated by Sinorhizobium fredii HH103 and Associated with Nodulation Traits in Soybean

Large amounts of nitrogen fertilizer are annually applied to improve soybean yield. However, the overuse of nitrogen fertilizers has resulted in significant environmental pollution. Biological nitrogen fixation is an ecological and environmentally friendly method to increase soybean yield. However, the signaling pathway and function of genes in the plant host regulated by rhizobia under the symbiotic relationship remain unknown. In this study, the chromosome region in soybean responsive to Sinorhizobium fredii HH103 was identified using chromosome-segment-substituted lines produced from a cross between cultivated soybean SN14 and wild soybean Zyd00006. In addition, candidate genes associated with nodulation traits and regulated by S. fredii HH103 were identified. In total, three quantitative trait loci (QTLs) containing 68 genes were identified on chromosomes 02, 05, and 20. The differentially expressed genes among the QTL regions were determined using RNA-seq and qRT-PCR. Glyma. 05G240500, a potential gene responding to S. fredii HH103 and positively regulating soybean nodulation, was identified. To explore the relationships between haplotypes and soybean nodulation phenotypes, SNPs found in the regulatory areas of Glyma.05G240500 haplotype were investigated. Our study revealed the role of Glyma.05G240500 in symbiosis and provided a reference for facilitating symbiotic nitrogen fixation in the field and for marker-assisted selection.

Analysis of technical efficiency’s lettuce farmers in Dalat City, Vietnam

The study aims to determine the technical efficiency and factors affecting the technical efficiency of lettuce farmers in Dalat City. The study’s primary data were collected by surveying structured questionnaires from 100 lettuce farmers in Dalat City. The Cobb-Douglas production, combined with the technical inefficiency according to the one-stage estimation method, was estimated by the program Frontier 4.1. The calculated results illustrate that the average technical efficiency of lettuce farmers is 0.76; with the usage level of available inputs and present techniques, Dalat lettuce production in the rainy season may increase by 24%. Besides, the study has also indicated that factors such as lettuce cultivated area, number of seedlings, and amount of pure potassium fertilizer positively influence lettuce yield. In contrast, the amount of pure nitrogen fertilizer negatively affected lettuce output. However, the education level and experience of household heads in lettuce cultivation positively affected technical efficiency. Therefore, to improve lettuce productivity and technical efficiency in Dalat City, the study suggests that farmers need to increase the amount of potassium fertilizer and reduce nitrogen fertilizer. In addition, state agencies recommend teaching lettuce farmers about the balanced and reasonable application of N, P, and K fertilizers through documents or training courses.

The Effects of Different Sowing Density and Nitrogen Topdressing on Wheat Were Investigated under the Cultivation Mode of Hole Sowing

Hole sowing is a new and efficient cultivation method with few studies. This study investigated the effects of different sowing densities and nitrogen topdressing at the jointing stage on dry matter, quality, and yield under wheat hole sowing to provide a theoretical basis for integrating wheat fertilizer and density-supporting technology. In this study, a two-factor split-plot design was used. The sowing density was the main plot, and four levels were set: D1, D2, D3, and D4 (238, 327, 386, and 386 suitable seeds·m−2). The four sowing levels were sown according to 8 grains/hole, 11 grains/hole, 13 grains/hole, and 16 grains/hole, respectively, with a row spacing of 25 cm and a hole spacing of 13.5 cm; the amount of nitrogen fertilizer applied at the jointing stage was the sub-area, with four levels: N1, N2, N3, and N4 (0, 60, 120, and 180 kg·ha−1). After two years of experimental research, the following main conclusions are drawn: the use of high sowing density and nitrogen topdressing is helpful to improve the dry matter quality of wheat spikes at the maturing stage; the sowing density had significant or highly significant effects on protein content, starch content, and sedimentation value. The yield from 2018–2019 reached a maximum of 8448.67 kg·ha−1 under D4N4 treatment, and the yield from 2019–2020 reached a maximum of 10,136.40 kg·ha−1 under D4N3 treatment. Therefore, the combination of 225 kg·ha−1 sowing density and 120–180 kg·ha−1 nitrogen topdressing at the jointing stage can be used in field production, which can help improve wheat production potential. Similarly, understanding the interaction between wheat hole sowing and different sowing densities and nitrogen topdressing amounts provides a practical reference for high-yield wheat cultivation techniques.

Response genotypes of sunflower (Helianthus annuus L.) and amount of nitrogen fertilizer on growth characteristics, oil yield, and its percentage

The field experiment was conducted during the spring and autumn seasons of 2021 in the Al-Haritha area, AL- Basra Governorate, to study the response of six genotypes of sunflower (Local, Aqmar, Ishaqi 1, Ishaqi 2, Turki Tarzan and Shmoos) and four levels of nitrogen fertilizer control treatment N0, N1 = (N100 kg. ha -1), N2 = (N200 kg.ha-1) and N3 = (N300 kg.ha-1) according to the complete randomized block design RCBD with three replications in the order of the split-plot design (the levels of nitrogen fertilization were distributed in the main plot and the varieties in the secondary Sub-plot). Results showed the superiority of the Shmoos genotype with the highest average number of leaves that, reached (27.05 and 29.41) leaves. plant-1. while the nitrogen fertilizer effect showed a superior fertilizer level of N3, which gave (26.32 and 29.94) leaves. plant-1. As for characteristic of fertility percentage, there were no significant differences between the genotypes (Local, Aqmar, and Tarzan) for the spring season; it appears the superiority of fertilizer level N3, which gave (93.79 and 91.79), Shmoos genotype was superior with the highest average yield of an individual plant (78.50 and 84.73) gm.plant-1 compared to the local genotype, which gave the lowest average of (44.80, and 51.23) gm.plant-1 for the two seasons, respectively, and N3 level of fertilizer, which gave average (77.82 and 88.88) gm.plant-1 and local composition outperformed the proportion of oil (39.55 and 41.13%) and the Shmoos genotype in the total oil yield (1161.4 and 1461.3) kg.ha-1, while this study showed the superiority of the fertilizer level N0 with the oil percentage, which gave (39.63 and 43.65%). As for the total oil yield, the composition was superior to Shamus by giving the highest mean of oil yield (1161.4 and 1461.3) kg.ha-1 for two seasons, respectively, and the superiority of the fertilizer level N3, which gave the highest oil yield (1,247.6 and 1673.6) kg.ha-1, for two seasons, respectively. Keywords: sunflower, genetic structures, nitrogen fertilizer

Synergistic phosphate fertilizer effects on soil nutrient and microbial diversity in wheat

AbstractIn this experiment, itaconic acid, maleic acid, acrylic acid, and potassium persulfate were polymerized to form synergist, which was wrapped on the surface of phosphate fertilizer particles to make synergistic phosphate fertilizer. In order to explore synergistic phosphate fertilizer effects on soil nutrient and microbial in wheat (Triticum aestivum), four treatments were designed—CK: nitrogen fertilizer (containing N 306.14 kg/hm2), potassium fertilizer (containing K2O 116.67 kg/hm2), conventional phosphate fertilizer (containing P2O5 333.35 kg/hm2); T1: synergic phosphate fertilizer (containing P2O5 249.99 kg/hm2); T2: synergic phosphate fertilizer (containing P2O5 166.67 kg/hm2); and T3: synergic phosphate fertilizer (containing P2O5 83.32 kg/hm2). The application amount of nitrogen and potassium fertilizer in T1, T2, and T3 was the same as that in CK. The soil nutrient concentration of different treatments was analyzed, and the microbial diversity of different treatments was analyzed by Illumina MISEP high‐throughput sequencing technology. The results showed that the T2 treatment performed the best. In 2020, the pH of T2 was 1.87% lower than that of CK, and the contents of alkali hydrolyzed nitrogen, available phosphorus, and available potassium were 5.8%, 11.44%, and 9.91% higher than CK, respectively. In 2021, the pH of T2 was 1.64% lower than that of CK, and the contents of alkali hydrolyzed nitrogen, available phosphorus, and available potassium were 1.06%, 7.89%, and 16.53% higher than CK, respectively. In addition, the application of synergistic phosphate fertilizer could improve the richness, diversity, and evenness of microorganisms in soil.