N2 Treatment Research Articles

Alfalfa (Medicago sativa L.) Nitrogen Utilization, Yield and Quality Respond to Nitrogen Application Level with Center Pivot Fertigation System

Nitrogen (N) application with a center-pivot fertigation system is commonly used for alfalfa production in the North China Plain, with its barren soil, but improper N application has resulted in lower N use efficiency and even negative effects on yield and quality. The effects of N application levels on soil NO3−-N content, nitrogen utilization, yield and quality of alfalfa at various cuttings and established years were evaluated under sprinkler fertigation to optimize the N application schedule. Four N application levels of 0, 12.5, 25 and 37.5 kg N ha−1 (N0, N1, N2 and N3) for each cutting were applied to alfalfa at the early vegetative stage from the first to third year after establishment. The results showed that the variation in soil NO3−-N content was mainly concentrated in the topsoil (0–40 cm) after N application via sprinkler fertigation. N uptake amount was dramatically improved through the N application for one-year-old alfalfa. Compared to the yield under the N0 treatment, the N application significantly improved the yield of alfalfa at the first two cuttings in the first year. The N use efficiency generally reached a high value with a low N application level. N application had an insignificant effect on the alfalfa quality classification during the three years. For obtaining high yield, quality and N use efficiency of alfalfa planted in the North China Plain, the N application level is recommended as 12.5 kg N ha−1 at the first cutting and 37.5 kg N ha−1 at the second cutting for one-year-old alfalfa.

Intercropping and appropriate nitrogen application control faba bean Fusarium wilt by improving physiological and biochemical resistance and protein expression of faba bean

AbstractThis study set up four nitrogen application levels (0, 45, 90 and 135 kg/ha) and two planting systems (faba bean monocropping and faba bean and wheat intercropping) to investigate the incidence of faba bean Fusarium wilt under different treatments and determine the resistance enzyme activities and gene expression, protein expression, and other indexes of faba bean plants. At all N levels, faba bean and wheat intercropping controlled faba bean Fusarium wilt by decreasing the content of hydrogen peroxide and superoxide anion in faba bean roots, increasing the enzyme activity and gene expression of the superoxide dismutase and the gene expression of pathogenesis‐related protein 1 (VfPR1), VfPR2, VfPR5 and VfPR10 disease resistance proteins in the roots, with the most significant effects at the N2 level (90 kg/ha). Further investigation of the impact of intercropping on faba bean roots using the N2 treatment showed that faba bean–wheat intercropping upregulated 288 proteins and downregulated 179 proteins compared with monocropping, and the functions of the upregulated proteins were mainly related to energy metabolism, antioxidant enzymes, stress and DNA repair. GO functional analysis showed that the upregulated proteins were mainly focused on the involvement in amide biological processes. KEGG enrichment analysis revealed that faba bean–wheat intercropping upregulated proteins involved in glutathione metabolism and ascorbic acid metabolism. In summary, at the N2 level, faba bean–wheat intercropping effectively mitigated root oxidative stress by enhancing antioxidant and disease resistance mechanisms in faba bean roots.

Using soil nitrogen amendments in mitigating ozone stress in agricultural crops: a case study of cluster beans.

The climate change scenario in the coming years is liable to have serious negative consequences on agricultural productivity. Increasing tropospheric ozone concentration is an important aspect of climate change, which, due to its oxidative nature, is injurious to the plants. Due to the multifarious nature and continuously increasing concentration of tropospheric ozone, it is prerequisite to develop strategies to manage ozone stress in plants. Present study not only evaluates the potential of soil nitrogen amendments in ameliorating ozone stress in plants, but also focuses upon the mechanistic approaches adopted by the different plant cultivars to combat ozone stress. Three doses of nitrogen amendments, recommended (N1), 1.5× recommended (N2) and 2× recommended (N3), were given to two cultivars (S-151 and PUSA-N) of Cymopsis tetragonoloba exposed to ambient ozone stress. Control plants were also maintained in which no nitrogen treatment was given. Nitrogen supplementation reduced the root nodulation frequency and leghaemoglobin content, which subsequently increased the cellular nitrogen metabolism as evident through increase in the activities of nitrate reductase and nitrite reductase in both the test cultivars. The positive effects of nitrogen amendments are clearly evident in the 1D protein profile studies which showed a greater accumulation of larger sub-units of RuBisCO in nitrogen amended plants. The results clearly indicate that N2 treatment effectively enhanced the yield of both the cultivars (84.8% and 76.37%, in S-151 and PUSA-N, respectively); however, the mechanistic approach adopted by the two cultivars was different. Whereas the yield quantity showed higher increments in S-151, the yield quality parameters (carbohydrates and nitrogen contents) responded more positively in PUSA-N.

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.

Water and Nitrogen Balance under Various Water and Fertilizer Regulation Modes

A experiment was conducted at the Jiangxi Province Center Station of Irrigation Experiment from 2019 to 2021 to study the water and nitrogen balance under water and fertilizer regulation modes. The study aimed to propose a recommended mode for paddy fields that could save water, control pollution, reduce gas emission, and improve fertilizer use efficiency. This study examined the impact of different irrigation methods and nitrogen application levels on water saving and emission reduction in paddy fields. The experiment included six treatments, which involved two irrigation methods (intermittent irrigation and flooding irrigation, referred to as W1 and W0, respectively) and three application rates of nitrogen fertilizer (0 kg/ha, 135 kg/ha, 180 kg/ha, referred to as N0, N1 and N2, respectively). The study found that irrigation methods had a significant effect on the amount of irrigation, drainage, leakage, nitrogen load from drainage, soil nitrification potential, and ammonia volatilization. The results showed that compared to flooding irrigation, intermittent irrigation reduced the amount of irrigation, drainage, leakage and nitrogen load from drainage by an average of 25.98%, 16.03%, 8.43% and 10.86%, respectively. However, the study also found that the nitrification potential and ammonia volatilization increased by an average of 6.45% and 4.32%, respectively. Fertilization levels had a significant effect on drainage nitrogen load, early soil nitrification potential and ammonia volatilization. Compared with the treatment of N2 (180 kg N/ha), the drainage nitrogen load under the treatment of N1 (135 kg N/ha) decreased by 10.86% on average, while nitrification potential and ammonia volatilization increased by 38.74% and 3.33%, respectively. In terms of nitrogen output, the amount of nitrogen absorbed by crops was the largest, followed by the nitrogen load from field drainage, then ammonia volatilization, and then denitrification. Considering the goals of water saving, emission reduction, and the efficient utilization of water and fertilizer in paddy fields, the optimal water and fertilizer regulation mode was the W1N1 mode (intermittent irrigation combined with reduced nitrogen fertilizer application rate, 135 kg N/ha).

Development of products based on ke-kame-tu formula for PMT at posyandu as an effort to prevent stunting

The "ke-kame-tu" formula is a mixture of Moringa leaf flour, red bean flour and tuna fish meal, with high protein, zinc, calcium, phosphorus and magnesium content. The specific aim of the research is to analyze the proximate content, amino acids, zinc, calcium, phosphorus and magnesium of supplementary feeding nugget products, and determine the most preferred supplementary feeding products. The “ke-kame-tu” formula (15-60-25) and supplementary feeding products were made using a randomized block design. Taste data was obtained using organoleptic tests. Analysis of calcium, phosphorus and magnesium using spectrophotometric methods. To determine the best supplementary feeding product, a diversity analysis (Anova) of organoleptic test results was carried out. The ke-kame-tu formula (15-60-35) contains 4.39 mg/100g of calcium, 530 mg/100 g of phosphorus, 80 mg/100 g of magnesium, 1.65 mg/100 g of zinc, and protein as much as 16.81%. In general, nuggets made using a modified recipe by adding to-kame-tu formulas with different concentrations have different nutritional content, namely increasing calcium, phosphorus, magnesium and protein content. Based on organoleptic tests, it was found that nugget products with N3 treatment were the preferred product compared to other treatments. This supplementary feeding product uses the addition of 100 grams of the second formula.

Polyvinylpyrrolidone-coated copper nanoparticles dose-dependently conferred tolerance to wheat under salinity and/or drought stress by improving photochemical activity and antioxidant system

Copper (Cu) is one of the essential micronutrients for plants and has been used extensively in agricultural applications from the past to the present. However, excess copper causes toxic effects such as inhibiting photosynthesis, and disrupting biochemical processes in plants. Nanotechnology applications have offered a critical method for minimizing adverse effects and improving the effectiveness of copper nanoparticles. For this purpose, this study investigated the physiological and biochemical effects of polyvinylpyrrolidone (PVP)-coated Cu nanoparticles (PVP–Cu NP, N1, 100 mg L−1; N2, 400 mg L−1) in Triticum aestivum under alone or combined with salt (S, 150 mM NaCl) and/or drought (D, %10 PEG-6000) stress. Salinity and water deprivation caused 51% and 22% growth retardation in wheat seedlings. The combined stress condition (S + D) resulted in an approximately 3-fold reduction in the osmotic potential of the leaves. PVP-Cu NP treatments to plants under stress, especially N1 dose, were effective in restoring growth rate and regulating water relations. All stress treatments limited gas exchange in stomata and suppressed the maximal quantum yield of PSII (Fv/Fm). More than 50% improvement was observed in stomatal permeability and carbon assimilation rate under S + N1 and S + N2 applications. Examination of OJIP transient parameters revealed that N1 treatments protected photochemical reactions by reducing the dissipated energy flux (DIo/RC) in drought and S + D conditions. Exposure to S and/or D stress caused high hydrogen peroxide (H2O2) accumulation and lipid peroxidation in wheat leaves. The results indicated that S + N1 and S + N2 treatments reduced oxidative damage by stimulating the activities of antioxidant enzymes superoxide dismutase (SOD), peroxidase (POX), and ascorbate peroxidase (APX). Although similar effects were observed at D and S + D conditions with 100 mg L−1 PVP-Cu NP treatments (N1), the curative effect of the N2 dose was not observed. In D + N1 and S + D + N1 groups, AsA regeneration and GSH redox status were maintained by triggering APX, GR, and other enzyme activities belonging to the AsA-GSH cycle. In these groups, N2 treatment did not contribute to the availability of enzymatic and non-enzymatic antioxidants. As a result, this study revealed that N1 dose PVP-Cu NP application was successful in providing stress tolerance and limiting copper-induced adverse effects under all stress conditions.

A dynamic regulation of nitrogen on floret primordia development in wheat

Nitrogen (N) fertilization is critical for spike and floret development, which affects the number of fertile florets per spike (NFFs). However, the physiological regulation of the floret development process by N fertilization is largely unknown. A high temporal-resolution investigation of floret primordia number and morphology, dry matter, and N availability was conducted under three N fertilization levels: 0 (N0), 120 (N1) and 240 (N2) kg ha−1. Interestingly, fertile florets at anthesis stage were determined by those floret primordia with meiotic ability at booting stage: meiotic ability was a threshold that predicted whether a floret primordium became fertile or abortive florets. Because the developmental rate of the 4th floret primordium in the central spikelet was accelerated and then they acquired meiotic ability, the NFFs increased gradually as N application increased, but the increase range decreased under N2. There were no differences in spike N concentration among treatments, but leaf N concentration was increased in the N1 and N2 treatments. Correspondingly, dry matter accumulation and N content of the leaf and spike in the N1 and N2 treatments was increased as compared to N0. Clearly, optimal N fertilization increased leaf N availability and transport of assimilates to spikes, and allowed more floret primordia to acquire meiotic ability and become fertile florets, finally increasing NFFs. There was no difference in leaf N concentration between N1 and N2 treatment, whereas soil N concentration at 0–60 cm soil layers was higher in N2 than in N1 treatment, implying that there was still some N fertilization that remained unused. Therefore, improving the leaf’s ability to further use N fertilizer is vital for greater NFFs.

Effect of Addition Nitrogen Fertilizer at Different Irrigation Levels on Saturated Hydraulic Conductivity by Using Two System of Irrigation

A field study was conducted in the province of Wasit - Kut, in a semi-arid region with a clay loam texture, for the purpose of studying the effect of adding nitrogen fertilizer, which included the level of 300 kg H-1 (N1) and 150 kg H-1 (N2) and the comparison treatment without adding fertilizer (N0) and using two levels of irrigation, which included EP (P1) 75%, EP (P2) 100% under drip irrigation (DI) and surface irrigation (SI) systems on saturated Hydraulic conductivity (Ks). The results showed that the addition of nitrogen fertilizer N1 had a significant effect by increasing the nitrogen availability using (DI), as the N1 gave the highest value of conductivity and a significant difference from the rest of the treatments, by increase 154.3% While the increase were 103.7% and 56.79% for the treatment N2 and N0, respectively. The results indicated that there were significant differences due to the effect of different irrigation levels on the Ks values, as P1 treatment gave the highest Ks value of 2.21 m day-1 compared with P2 treatment, which amounted to 1.94 m day-1, With the presence of significant differences for the two irrigation systems on the Ks values, as the values increased compared with the values before planting, with an increase of 129.6% and 38.27% for the (DI) and (SI) system. The study also showed that there were significant differences for the effect of the interaction between nitrogen fertilizer treatments and the irrigation levels, as well as the presence of significant differences for the effect of the interaction between the nitrogen fertilizer treatments and the irrigation system used on the Ks values.

Understory vegetation had important impact on soil microbial characteristics than canopy tree under N addition in a Pinus tabuliformis plantation

Forest ecosystem is a complex community, and its soil microbes play a vital role in global matter cycling. However, the patterns of rhizosphere soil microbial characteristics among tree-shrub-grass and their responses to nitrogen (N) deposition are still unclear. This study evaluated the microbial biomasses, processes (gas fluxes), and enzyme activities in the rhizosphere soils of tree (Pinus tabuliformis), shrub (Rosa xanthina), and grass (Carex lanceolata) and their responses to N addition (0, 3, 6, 9 g N m−2 y−1 corresponding to N0, N3, N6, N9) in a P. tabuliformis plantation. (1) Microbial biomass carbon (MBC), microbial biomass nitrogen (MBN), microbial biomass phosphorus (MBP) contents, as well as CO2, CH4 flux rates in the rhizosphere soil of C. lanceolata were significantly higher than those in the rhizosphere soils of P. tabuliformis and R. xanthina (P < 0.05). The activities of alkaline phosphatase (ALT), leucine aminopeptidase (LAP), β-glucosidase (BG), D-cellulosidase (CBH), N-acetyl-glucosaminidase (NAG), and xylosidase (XYL) in the rhizosphere soils of C. lanceolata and R. xanthina were significantly higher than those in the rhizosphere soil of P. tabuliformis. (2) Soil MBC content, N2O, and CH4 flux rates increased after N addition, while the CO2 flux rate decreased. MBP content initially increased and then reduced with N additions, and the maximum values observed in N3 or N9 treatments. (3) In the rhizosphere soil of P. tabuliformis, N addition enhanced the NAG, BG, CBH, and XYL activities. While low N increased and high N decreased these enzyme activities in the rhizosphere soils of C. lanceolata and R. xanthina, with the maximum values obtained in N3 treatment. (4) N addition directly reduced the CO2 flux rate and indirectly enhanced the gas flux rate by increasing soil MBC and MBP contents. Species change indirectly affected the microbial biomass and enzyme activity by altering soil chemical properties, which eventually affected gas flux rates. Our study emphasizes the effects of tree-shrub-grass on soil microbial characteristics, which can improve the evaluation of soil ecological processes and responses to N deposition in forest ecosystems.

Application of Modified Atmospheres to Control Stegobium paniceum and Lasioderma serricorne Infestation of Stored Chamomile and Coriander and Its Effect On Product Quality

AbstractMedicinal and spices plants are crucial, and they can become infested by several insects, such as drugstore beetle (Stegobium paniceum l.) and the cigarette beetle (Lasioderma serricorne), during storage. Therefore, the present study aimed to assess the effect of enriched modified atmospheres (MAs), with CO2 or N2, on L. serricorne and S. paniceum adults and larvae and their effect on quality of chamomile flowers and coriander seeds during storage. Various carbon dioxide and nitrogen gas concentrations were tested, including 40% CO2, 50% CO2, 60% CO2, 97% N2, and 98% N2. The larval mortality for S. paniceum reached 100% after 6 days of 60% CO2 and 8 days for the L. serricorne. At 98% N2 treatment, the complete mortality (100%) of S. paniceum and L. serricorne adults was recorded following 3 and 9 day exposures and of larvae following 10 day exposure.The quality parameters (weight loss percentage, germination, essential oil percentage, and color) of chamomile flower and coriander seeds treated with 60% CO2 and control were studied after 3 and 6 months of storage. The MAs had the lowest weight loss percentage, the highest lightness value, the lowest color changes, and the highest essential oil content of chamomile flower and coriander seeds compared with the control treatment. Additionally, the MAs induced a higher germination percentage of coriander seeds compared with the control. Treatment with CO2 increased some essential oils compounds, compared with control after 6 months of storage of chamomile. All compounds were decreased in coriander seeds treated with CO2, except for carvone and anethole, which were increased. In conclusion, our study recommends using MAs to control S. paniceum and L. serricorne during storage and maintain the quality of chamomile flower and coriander seed.

Response of Aleo vera plant to different concentrations of phosphorous and terra-sorb complex and its effect on vegetative growth characteristics and its gel content

Agricultural Engineering Sciences - University of Baghdad for the fall season 2016. Aloe vera seedlings were selected with a high degree of homogeneity in terms of vegetative growth and number of leaves, and the plants were distributed as a factorial experiment according to the RCBD randomized complete block design, with three replications and an average of six plants in the experimental unit. Results revealed significant differences in most of the studied traits. They showed the superiority of the N3P3 interference treatment by giving the highest values in the number of leaves, leaf width and thickness, fresh weight of leaves and plant yield of dry matter (15.83 leaves. and 217.46 g. plant-1), respectively. As for the effect of spraying with amino acids, treatment N3 excelled in the characteristics of leaf thickness, fresh weight of leaves and plant yield of dry matter, which amounted to 1.828 mm. leaf and 273.0 g. leaf and 157.23 g. leaf-1 in sequence. The treatment of P3 spraying surpassed the characteristic of leaf thickness and plant yield of dry matter, which amounted to 1.822 mm. leaf-1 and 191.61 g. plant-1. The results did not show significant differences between spraying with amino acids and phosphorous treatments in plant length and leaf width. Keywords: Aloe vera, biostimulant, amino acids, phosphorous

Effects of postponing nitrogen topdressing on starch structural properties of superior and inferior grains in hybrid indica rice cultivars with different taste values.

Nitrogen (N) fertilizer management, especially postponing N topdressing can affect rice eating quality by regulating starch quality of superior and inferior grains, but the details are unclear. This study aimed to evaluate the effects of N topdressing on starch structure and properties of superior and inferior grains in hybrid indica rice with different tastes and to clarify the relationship between starch structure, properties, and taste quality. Two hybrid indica rice varieties, namely the low-taste Fyou 498 and high-taste Shuangyou 573, were used as experimental materials. Based on 150 kg·N hm-2, three N fertilizer treatments were established: zero N (N0), local farmer practice (basal fertilizer: tillering fertilizer: panicle fertilizer=7:3:0) (N1), postponing N topdressing (basal fertilizer: tillering fertilizer: panicle fertilizer=3:1:6) (N2). The starch granules of superior grains were more complete, and the decrease in small granules content and the stability of starch crystals were a certain extent less than those of inferior grains. Compared with N1, under N2, low-taste and high-taste varieties large starch granules content were significantly reduced by 6.89%, 0.74% in superior grains and 4.26%, 2.71% in inferior grains, the (B2 + B3) chains was significantly reduced by 1.61%, 0.98% in superior grains, and 1.18%, 0.97% in inferior grains, both reduced the relative crystallinity and 1045/1022 cm-1, thereby decreasing the stability of the starch crystalline region and the orderliness of starch granules. N2 treatment reduced the ΔHgel of two varieties. These changes ultimately contributed to the enhancement of the taste values in superior and inferior grains in both varieties, especially the inferior grains. Correlation analysis showed that the average starch volume diameter (D[4,3]) and relative crystallinity were significantly positively correlated with the taste value of superior and inferior sgrains, suggesting their potential use as an evaluation index for the simultaneous enhancement of the taste value of rice with superior and inferior grains. Based on 150 kg·N hm-2, postponing N topdressing (basal fertilizer: tillering fertilizer: panicle fertilizer=3:1:6) promotes the enhancement of the overall taste value and provides theoretical information for the production of rice with high quality.

The effect of nitrogen splitting on some agronomic and physiological traits of two corn cultivars under normal irrigation and drought stress

To examine the effect of nitrogen splitting on some agronomic and physiological traits of two corn cultivars under normal irrigation and drought stress, a factorial split plot experiment was implemented in Tehran (Iran) in 2017-2019. Main factors included irrigation at two levels of normal irrigation (I1: irrigation after 60-mm evaporation from Class A pan) and stress (I2: irrigation after 120-mm evaporation) and nitrogen splitting at four levels (N1: 1/2 after emergence + 1/2 after 8-leaves stage, N2: 1/3 after emergence + 1/3 after 8-leaves stage + 1/3 after emergence of male inflorescence, N3: 1/4 after emergence + 1/2 after 8-leaves stage + 1/4 after emergence of male inflorescence, and N4: 1/4 after emergence + 1/4 after 8-leaves stage + 1/2 after emergence of male inflorescence) and sub-factor of cultivar was considered at two levels (C1: Single cross 704 cultivar and C2: Maxima cultivar). Drought stress significantly declined the number of seed rows per cob, 100-seed weight, and relative humidity, and significantly increased proline and abscisic acid contents. Maxima cultivar had the highest proline content and abscisic acid activity in N1 fertilizer treatment and under stress conditions. With an average of 9541 kg ha−1, N3 treatment had the highest seed yield. Single cross 704 cultivar exhibited more resistance to drought stress and nitrogen deficiency. Consequently, it may be used in arid climates. Proper nitrogen splitting could enhance yield in both corn cultivars even under stress conditions. Thus, the effect of this key factor on improving corn yield should be considered.

Optimasi Ukuran Pot dan Dosis Pupuk pada Budidaya Melon (Cucumis melo L)

This research aimed to determine the optimum pot size and fertilizer dosage for melon (Cucumis melo L) cultivation based on productivity. The experiment used a Completely Randomized Design (CRD) arranged factorially with 2 factors and two replicates. The first factor was the dose of compost fertilizer (D) which consists of 1500 g (D1), 1500 g+10 g NPK (D2), 2000 g (D3), and 2000 g+10 g NPK (D4), and the second factor was the pot size or volume of growth media (N) consisting of 5 liters (N1), 10 liters (N2), and 20 liters (N3). The results showed that fertilizer dosage had no effect on all parameters, while pot size had an effect on fresh fruit weight, plant height, fruit circumference, stem diameter and water productivity, but had no effect on sweetness level, number of leaves and root weight. If seen from fruit weight and water productivity, the N2 treatment factor is the best treatment factor. Therefore; the D1N2 treatment combination could be chosen as the optimum treatment because it produced fruit weights of 1434.58-1532.36 g and an average water productivity of 39.07kg/m3. Keywords: Compost Dose, Melon Cultivation, Pot Size, Water Productivity.

Effects of Different Water and Nitrogen Supply Modes on Peanut Growth and Water and Nitrogen Use Efficiency under Mulched Drip Irrigation in Xinjiang.

The optimization of irrigation and fertilization indexes for peanuts with drip irrigation is urgently needed in Xinjiang. A field experiment was conducted during the 2021 peanut growing season at Urumqi, Xinjiang, in Northwestern China, to evaluate the effects of different water and nitrogen treatments on the growth, yield, and water and nitrogen utilization of peanuts. In field experiments, we set up three irrigation levels (irrigation water quotas of 22.5, 30, and 37.5 mm, respectively, for W1, W2, and W3), two nitrogen application levels (77.5 and 110 kg·ha-1, recorded as N1 and N2), and a control treatment (W2N0) that did not include the application of nitrogen. The results showed that nitrogen application enhanced the growth, physiological indexes, yield, and water use efficiency of the W1, W2, and W3 treatments when the irrigation volume remained the same. In comparison with no nitrogen application (W2N0), the peanut growth, physiological indexes, yield, and water use efficiency improved with increasing irrigation amounts in the N1 and N2 treatments. With an increase in the irrigation volume, the water use efficiency grew; the W3N2 treatment had the highest water use efficiency, which was 1.32 kg·m-3. The total water consumption and reproductive-stage water consumption of the peanuts in all treatments increased with the irrigation volume, and a high yield was achieved at 402.57 mm, which was 5.2974 Mg·ha-1. In the W1, W2, and W3 treatments, the nitrogen partial factor productivity significantly decreased as the nitrogen application increased, with the nitrogen partial factor productivity in the W3N1 treatment being the highest, at 60.61 kg·kg-1. A comprehensive evaluation based on principal component analysis assigned W3N2 the higher score. These findings suggest that irrigation water quotas of 37.5 mm should be coupled with 110 kg·ha-1 nitrogen applications for peanuts using drip irrigation in mulch film in Xinjiang.

Linking microbial carbon‐degrading potential to organic carbon sequestration in fertilized soils: Insights from metagenomics

AbstractThe capacity of soils to store organic carbon (SOC) is vital for agricultural productivity. Soil microorganisms exert a critical role in carbon (C) flow and potentially influence C balance through the decomposition of plant and microbial dead biomass. However, the connection between the microbial degradation potential of plant‐derived and microbial‐derived C and soil organic carbon sequestration (SOCSR) under organic and inorganic nitrogen (N) fertilization treatments remains largely unexplored using metagenomics. In this study, metagenomics was used to investigate the effects of 4 years inorganic (N1: 250 kg N ha−1 yr−1 and N3: 450 kg N ha−1 yr−1) and organic N (O1: N1 + 11,250 kg ha−1 yr−1 sheep manure and O3: N1 + 18,750 kg ha−1 yr−1 sheep manure) fertilizer application on plant biomass decomposition genes, microbial biomass decomposition genes, and microbial properties related to different sources of C decomposition (species composition and diversity). Furthermore, the study explored the relationship between organic matter decomposition genes, microorganisms, and SOCSR. The results revealed that compared with N1 treatment, the increased application of inorganic N fertilizer (N3) significantly enhanced the abundance of genes related to plant and microbial biomass decomposition and microbial diversity involved in SOC decomposition, resulting in reduced SOC content. Conversely, the increased application of organic N fertilizer (O1 and O3) had a minor effect on the abundance of genes related to different sources of C decomposition and C decomposing microbial diversity, but reduced microbial entropy (the ratio of microbial biomass carbon to SOC) and increased SOC content. The random forest model highlighted that plant biomass decomposition genes and bacterial community composition were important factors affecting SOCSR. The Mantel test also indicated that the genes involved in the decomposition of lignin, cellulose, and hemicellulose were closely related to SOCSR. These findings highlighted that increased inorganic N fertilizers greatly enhanced the microbial capacity for SOC decomposition, resulting in reduced SOC accumulation. While the increased application of organic N fertilizer increased SOC stability and reduced the mineralization potential of SOC, contributing to SOCSR. Overall, these findings provide a greater understanding of the relationship between soil C turnover and microbial C‐degrading potential under short‐term fertilization. And in a long time, they may have important implications for global strategies aimed at increasing SOCSR to restore fertility and facilitate sustainable agricultural development.

Nitrogen fertilization promoted microbial growth and N2O emissions by increasing the abundance of nirS and nosZ denitrifiers in semiarid maize field.

Nitrous oxide (N2O) emissions are a major source of gaseous nitrogen loss, causing environmental pollution. The low organic content in the Loess Plateau region, coupled with the high fertilizer demand of maize, further exacerbates these N losses. N fertilizers play a primary role in N2O emissions by influencing soil denitrifying bacteria, however, the underlying microbial mechanisms that contribute to N2O emissions have not been fully explored. Therefore, the research aimed to gain insights into the intricate relationships between N fertilization, soil denitrification, N2O emissions, potential denitrification activity (PDA), and maize nitrogen use efficiency (NUE) in semi-arid regions. Four nitrogen (N) fertilizer rates, namely N0, N1, N2, and N3 (representing 0, 100, 200, and 300 kg ha-1 yr.-1, respectively) were applied to maize field. The cumulative N2O emissions were 32 and 33% higher under N2 and 37 and 39% higher under N3 in the 2020 and 2021, respectively, than the N0 treatment. N fertilization rates impacted the abundance, composition, and network of soil denitrifying communities (nirS and nosZ) in the bulk and rhizosphere soil. Additionally, within the nirS community, the genera Cupriavidus and Rhodanobacter were associated with N2O emissions. Conversely, in the nosZ denitrifier, the genera Azospirillum, Mesorhizobium, and Microvirga in the bulk and rhizosphere soil reduced N2O emissions. Further analysis using both random forest and structural equation model (SEM) revealed that specific soil properties (pH, NO3--N, SOC, SWC, and DON), and the presence of nirS-harboring denitrification, were positively associated with PDA activities, respectively, and exhibited a significant association to N2O emissions and PDA activities but expressed a negative effect on maize NUE. However, nosZ-harboring denitrification showed an opposite trend, suggesting different effects on these variables. Our findings suggest that N fertilization promoted microbial growth and N2O emissions by increasing the abundance of nirS and nosZ denitrifiers and altering the composition of their communities. This study provides new insights into the relationships among soil microbiome, maize productivity, NUE, and soil N2O emissions in semi-arid regions.

Optimizing Sowing Patterns and Nitrogen Management Strategies Used to Balance Maize Crop Productivity, N2O Emissions, and Economic Benefits in the Loess Plateau Region of China

Understanding the combined effects of sowing patterns and nitrogen (N) management strategies on crop productivity, environmental costs, and economic benefits is important to ensuring the sustainable development of dryland agriculture. Thus, we conducted a three-year field experiment to explore two spring maize sowing patterns (FS, flat sowing; RFPM, ridge and furrow plastic film mulching) and four N management strategies (N0, no N fertilizer; N1, normal urea as base fertilizer; N2, split application of normal urea at sowing and a large flare period at a ratio of 3:2; N3, all controlled-release urea as base fertilizer) on growth, the grain yield, the N uptake and utilization efficiency, N2O emissions, and economic benefits in the Loess Plateau region of China. Our results showed that compared to FS, RFPM promoted growth of the spring maize canopy and increased the grain yield, cumulative N uptake, and N use efficiency. RFPM promoted N2O emissions by improving the soil’s hydrothermal environment, but it reduced the environmental cost (yield-scaled N2O emission). RFPM increased the production cost, but it increased the net income by improving the total output. Compared to traditional N management strategies (N1), N2 and N3 treatments improved the spring maize productivity and net income, and they reduced the environmental costs by improving the synchronization of the nitrogen supply. However, due to the decreasing rural labor force available in China, N3 is more beneficial in terms of reducing labor inputs. Therefore, we suggest that RFPM and N3 can be combined to form an efficient management strategy for spring maize production in the Loess Plateau that balances crop productivity, N2O emissions, and economic benefits.

Development of a Concurrent Treatment Technique of Ethyl Formate and Mixtures (Nitrogen, Phosphine) to Control Citrus Mealybug (Planococcus citri).

Currently, the fumigant ethyl formate (EF) is stored as a liquified gas in metal cylinders mixed with carbon dioxide (CO2), but this product type is expensive to manufacture, transport, and maintain in cylinders. To address these problems, we developed a new EF fumigation technique with a nitrogen (N2) carrier. In this report, the susceptibility of citrus mealybugs, one of the most resistant mealybugs to fumigants, to EF was assessed; the phytotoxicity of an EF + N2 concurrent treatment applied to banana fruit was examined to evaluate the efficacy compared to the current EF + CO2 product; and the increased efficacy with a phosphine (PH3) addition to EF + N2 was also assessed. Concurrent treatment of EF and N2 was performed at an LC50 concentration of EF. N2 was applied in seven doses from concentrations of 79% to 95%. The phytotoxicity of EF to bananas was assessed by applying EF at 35 mg/L with N2 at 79%, and the color, sugar content, and weight loss of bananas were measured for 14 days after treatment. The EF with N2 treatment resulted in more than 50% mortality at all growth stages of the mealybug, and there was no significant difference between the untreated and treated banana fruits. EF mixed with PH3 showed a higher efficacy than treatment with EF alone, but only a slight increase in efficacy was observed when the PH3 concentration increased. These results indicate that concurrent treatment with EF and N2 can be used to control mealybugs on banana fruits, and combined treatment with EF and PH3 can also enhance the efficacy against mealybugs.