Nitrogen Fertilizer Supply Research Articles

Optimizing nitrogen fertilizer for improved root growth, nitrogen utilization, and yield of cotton under mulched drip irrigation in southern Xinjiang, China

The root system plays a crucial role in water and nutrient absorption, making it a significant factor affected by nitrogen (N) availability in the soil. However, the intricate dynamics and distribution patterns of cotton (Gossypium hirsutum L.) root density and N nutrient under varying N supplies in Southern Xinjiang, China, have not been thoroughly understood. A two-year experiment (2021 and 2022) was conducted to determine the effects of five N rates (0, 150, 225, 300, and 450 kg N ha−1) on the root system, shoot growth, N uptake and distribution, and cotton yield. Compared to the N0 treatment (0 kg N ha−1), the application of N fertilizer at a rate of 300 kg N ha−1 resulted in consistent and higher seed cotton yields of 5875 kg ha−1 and 6815 kg ha−1 in 2021 and 2022, respectively. This N fertilization also led to a significant improvement in dry matter weight and N uptake by 32.4% and 53.7%, respectively. Furthermore, applying N fertilizer at a rate of 225 kg N ha−1 significantly increased root length density (RLD), root surface density (RSD), and root volume density (RVD) by 49.6–113.3%, 29.1–95.1%, and 42.2–64.4%, respectively, compared to the treatment without N fertilization (0 kg N ha−1). Notably, the roots in the 0–20 cm soil layers exhibited a stronger response to N fertilization compared to the roots distributed in the 20–40 cm soil layers. The root morphology parameters (RLD, RSD, and RVD) at specific soil depths (0–10 cm in the seedling stage, 10–25 cm in the bud stage, and 20–40 cm in the peak boll stage) were significantly associated with N uptake and seed cotton yield. Optimizing nitrogen fertilizer supply within the range of 225–300 kg N ha−1 can enhance root foraging, thereby promoting the interaction between roots and shoots and ultimately improving cotton production in arid areas.

Evaluation of Nitrogen Fertilizer Supply and Soil Nitrate Thresholds for High Yields of Foxtail Millet

Foxtail millet is an important cereal crop in the North China Plain. However, excessive nitrogen fertilizer application over the years has led to declining yield and soil quality. This study investigated nutrient management strategies for foxtail millet based on crop yield levels and soil nutrient availability. In a field where targeted fertilization was conducted over six seasons, nitrogen fertilization effects and the dynamics of soil-available nitrogen were monitored continuously for two consecutive years (2022–2023) across five different foxtail millet varieties with varying yield levels. The study aimed to determine the optimal nitrogen application rate for achieving a high yield of foxtail millet, the minimum soil nitrate threshold required to maintain soil fertility, and the effective nitrogen application rate range for sustaining soil-available nitrate levels. Results showed that fertilization significantly affected dry matter weight during flowering, while variety affected dry matter weight at maturity. The average nitrogen application rate for achieving high yield across all five millet varieties was 141.3 kg·ha−1. Specifically, the average nitrogen application rate of nitrogen-efficient varieties achieving high yield (5607.32–5637.19 kg·ha−1) was 151.5 kg·ha−1, while the average nitrogen application rate of nitrogen-inefficient varieties achieving high yield (4749.77–4847.74 kg·ha−1) was 134.5 kg·ha−1. Soil NH4+-N and NO3−-N content increased when nitrogen application rate exceeded 360 kg·ha−1, posing environmental risks. To achieve high yield, soil nitrate levels would be maintained at an average of 17.23 mg·kg−1 (before sowing) and 9.75 mg·kg−1 (at maturity). A relationship between soil nitrate and nitrogen application rate was established: y = 867.5 − 50z (where y represents the optimal nitrogen application rate for high yield (kg·ha−1), and z represents soil NO3−-N content in the 0–20 cm layer before sowing, ranging from 10.0 to 17.35 mg·kg−1), which provided a practical method for nitrogen fertilization to achieve high yield of foxtail millet. In this study, the fertilization strategy was optimized according to soil nutrient level and yield targets, and the nitrogen application rate was controlled within 360 kg·ha−1 based on the soil nitrate nitrogen content, which will be instructive for reducing fertilizer use, maximizing fertilizer efficiency, and increasing yield.

Optimal Nitrogen Fertilizer Rates for Soybean Cultivation

The soybean (Glycine max. L. Merr) can satisfy a large portion of its requirement for nitrogen (N) by living in symbiosis with symbiotic bacteria. However, this source of N may be inadequate in varieties with high yield potential. To fully exploit this potential, soybeans should additionally utilize mineral forms of nitrogen present in the soil. The aim of this study was to determine the effect of varied nitrogen fertilizer application rates on the dry weight of the separated parts of soybean plants and the whole plant, including the number and weight of root nodules, the potential to reduce atmospheric nitrogen (N2), and the content and uptake of nitrogen. Four levels of pre-sowing nitrogen fertilizer supply were tested: 0, 60, 120, and 180 kg N·ha−1. Measurements of the tested parameters were taken during the flowering stage and the fully ripe stage. During the flowering stage, a reduction in the number of root nodules was observed following the application of 120 and 180 kg N·ha−1. In the fully ripe stage, each increase in nitrogen application caused a systematic decrease in the number of nodules on the roots. Increasing the level of nitrogen application therefore reduced the N2 fixation potential of soybeans, regardless of the developmental stage. The use of high doses of nitrogen in soybean cultivation did not increase seed yield or the weight of the entire plant. With high doses of nitrogen, the content and accumulation of nitrogen in soybean seeds and total mass did not increase. Therefore, the content and yield of crude protein did not increase. The main organ of nitrogen accumulation in the soybean flowering stage was the leaves (58.6–64.8% of total N uptake), however, in the fully ripe stage, it was the seeds (66.8–74.2% of total N uptake).

Feasibility study of Aesculus turbinata fruit shell-derived biochar for ammonia removal in wastewater and its subsequent use as nitrogen fertilizer

In the face of increasing nitrogen demand for crop cultivation driven by population growth, this study presents a sustainable solution to address both the heightened demand and the energy-intensive process of nitrogen removal from wastewater. Our approach involves the removal of nitrogen from wastewater and its subsequent return to the soil as a fertilizer. Using biochar derived from Aesculus turbinata fruit shells (ATFS), a by-product of post-medical use, we investigated the effect of pyrolysis temperature on the NH4–N adsorption capacity of ATFS biochar (ATFS-BC). Notably, the ATFS-BC pyrolyzed at 300 °C (ATFS-BC300) exhibited the highest NH4–N adsorption capacity of 15.61 mg/g. The superior performance of ATFS-BC300 was attributed to its higher number of oxygen functional groups and more negatively charged surface, which contributed to the enhanced NH4–N adsorption. The removal of NH4–N by ATFS-BC300 involved both physical diffusion and chemisorption, with NH4–N forming a robust multilayer adsorption on the biochar. Alkaline conditions favored NH4–N adsorption by ATFS-BC300; however, the presence of trivalent and divalent ions hindered this process. Rice plants were cultivated to assess the potential of NH4–N adsorbed ATFS-BC300 (NH4-ATFS-BC300) as a nitrogen fertilizer. Remarkably, medium doses of NH4-ATFS-BC300 (594.5 kg/ha) exhibited key agronomic traits similar to those of the commercial nitrogen fertilizer in rice seedlings. Furthermore, high doses of NH4-ATFS-BC300 demonstrated superior agronomic traits compared to the commercial fertilizer. This study establishes the viability of utilizing ATFS-BC300 as a dual-purpose solution for wastewater treatment and nitrogen fertilizer supply, presenting a promising avenue for addressing environmental challenges.

Strigolactone and gibberellin signaling coordinately regulate metabolic adaptations to changes in nitrogen availability in rice

Modern semi-dwarf rice varieties of the “Green Revolution” require a high supply of nitrogen (N) fertilizer to produce high yields. A better understanding of the interplay between N metabolism and plant developmental processes is required for improved N-use efficiency and agricultural sustainability. Here, we show that strigolactones (SLs) modulate root metabolic and developmental adaptations to low N availability for ensuring efficient uptake and translocation of available N. The key repressor DWARF 53 (D53) of the SL signaling pathway interacts with the transcription factor GROWTH-REGULATING FACTOR 4 (GRF4) and prevents GRF4 from binding to its target gene promoters. N limitation induces the accumulation of SLs, which in turn promotes SL-mediated degradation of D53, leading to the release of GRF4 and thus promoting the expression of genes associated with N metabolism. N limitation also induces degradation of the DELLA protein SLENDER RICE 1 (SLR1) in an D14- and D53-dependent manner, effectively releasing GRF4 from competitive inhibition caused by SLR1. Collectively, our findings reveal a previously unrecognized mechanism underlying SL and gibberellin crosstalk in response to N availability, advancing our understanding of plant growth–metabolic coordination and facilitating the design of the strategies for improving N-use efficiency in high-yield crops.

Effects of different dose of nitrogen and lime on soil properties and maize (Zea mays L.) on acidic nitisols of Northwestern Ethiopia

This study was carried out on the nitisols of Burie district, Ethiopia to examine the effect of integrated use of lime and nitrogen on soil physicochemical properties and maize yield. Two levels of lime (0 and 0.5 t/ha) and five-level of nitrogen (0, 46, 92, 138 and 184 kg N/ ha) were laidout in randomized complete block design with three replications. The results indicated that among before planting, soil bulk density (BD), pH, soil organic carbon (OC), total nitrogen (TN), available P and CEC were 1.42 g/cm3, 5.2 (strongly acidic), 1.32% (very low), 0.12% (low), 8.86 mg /kg (very low), and 19.57 cmolc /kg (medium), respectively. The physicochemical properties except bulk density increased. The lowest soil BD (1.21 g/m3) was from plots treated with 0.5 t/ha lime and 184 kg N/ ha. The maximum soil pH (6.85) was obtained from plots treated with 184 kg N/ ha and 0.5 t/ha lime. The maximum soil CEC (35.38 (cmolc /kg) was obtained from plots treated with 184 kg N/ ha and 0.5 t/ha lime. Level of lime, nitrogen fertilizer, and interaction effects of lime and nitrogen fertilizer (L×N) significantly affected maize yield (p<0.001). Indeed yield of maize has positive correlations with most soil physicochemical properties but negative with BD (r= -0.543). The adjusted yield and net benefits was 6.4 t/ha and 1101.77$. Inherent physicochemical properties of the soil are changed either by sole or combined use of lime and N fertilizer. Soils tilled with 0.5 t/ha lime and 138 kg/ha nitrogen were found in maximum net benefit. Residual long-term effects should be researched. Thus, liming should be given an emphasis on acidic soil amelioration. Moreover, the government may facilitate the supply of lime and nitrogen fertilizer to the farmers.

Global Wheat Production and Threats to Supply Chains in a Volatile Climate Change and Energy Crisis

As climate change and energy crises increase, NPK (nitrogen, phosphorus and potassium) fertilizer supply chains become more volatile. Globally, the Russian attack on Ukraine has caused the cost of gas to rise and fertilizer supplies to decline. This aggression may worsen the energy and wheat resource crisis in global supply chains. As a result of the escalation of hostilities, natural gas, oil, and coal prices have rapidly increased. In the years preceding the conflict, the agricultural sector had already begun to suffer, caused by unprecedented increases in the prices of natural gas and raw materials for the production of fertilizers stemming from Russian manipulation, especially in the gas market. Prior to the growing season, farmers were still unable to afford fertilizer prices. This situation will be exacerbated by the war. We can conclude from our results that European countries and the United States have high wheat production potential. Developed countries have significant nitrogen, phosphorus, and potassium fertilizer resources. Ukraine has a large yield gap, ranging between 4.5 and 7 Mg/ha. Wheat supply crises can be caused by tense geopolitical affairs, including military aggression and economic embargoes. Based on this, we recommend that decision-makers focus on crop quality to increase the country’s own production.

Screening of differentially expressed microRNAs and target genes in two potato varieties under nitrogen stress

BackgroundA reasonable supply of nitrogen (N) fertilizer is essential for obtaining high-quality, high-level, and stable potato yields, and an improvement in the N utilization efficiency can effectively reduce N fertilizer use. It is important to use accurate, straightforward, and efficient transgenic breeding techniques for the identification of genes that can improve nitrogen use efficiency, thus enabling us to achieve the ultimate goal of breeding N-efficient potato varieties. In recent years, some of the mechanisms of miRNAs have been elucidated via the analysis of the correlation between the expression levels of potato miRNA target genes and regulated genes under conditions of stress, but the role of miRNAs in the inhibition/expression of key genes regulating N metabolism under N stress is still unclear. Our study aimed to identify the role played by specific enzymes and miRNAs in the responses of plants to N stress.ResultsThe roots and leaves of the N-efficient potato variety, Yanshu4 ("Y"), and N-inefficient potato variety, Atlantic ("D"), were collected at the seedling and budding stages after they were exposed to different N fertilizer treatments. The miRNAs expressed differentially under the two types of N stress and their corresponding target genes were first predicted using miRNA and degradome analysis. Then, quantitative polymerase chain reaction (qRT-PCR) was performed to verify the expression of differential miRNAs that were closely related to N metabolism. Finally, the shearing relationship between stu-miR396-5p and its target gene StNiR was determined by analyzing luciferase activity levels. The results showed that NiR activity increased significantly with an increase in the applied N levels from the seedling stage to the budding stage, and NiR responded significantly to different N treatments. miRNA sequencing enabled us to predict 48 families with conserved miRNAs that were mainly involved in N metabolism, carbon metabolism, and amino acid biosynthesis. The differences in the expression of the following miRNAs were identified via screening (high expression levels and P < 0.05): stu-miR396-5p, stu-miR408b-3p_R-1, stu-miR3627-3p, stu-miR482a-3p, stu-miR8036-3p, stu-miR482a-5p, stu-miR827-5p, stu-miR156a_L-1, stu-miR827-3p, stu-miR172b-5p, stu-miR6022-p3_7, stu-miR398a-5p, and stu-miR166c-5p_L-3. Degradome analysis showed that most miRNAs had many-to-many relationships with target genes. The main target genes involved in N metabolism were NiR, NiR1, NRT2.5, and NRT2.7. qRT-PCR analysis showed that there were significant differences in the expression levels of stu-miR396-5p, stu-miR8036-3p, and stu-miR482a-3p in the leaves and roots of the Yanshu4 and Atlantic varieties at the seedling and budding stages under conditions that involved no N and excessive N application; the expression of these miRNAs was induced in response to N stress. The correlation between the differential expression of stu-miR396-5p and its corresponding target gene NiR was further verified by determining the luciferase activity level and was found to be strongly negative.ConclusionThe activity of NiR was significantly positively correlated with N application from the seedling to the budding stage. Differential miRNAs and target genes showed a many-to-many relationship with each other. The expression of stu-miR396-5p, stu-miR482a-3p, and stu-miR8036-3p in the roots and leaves of the Yanshu4 and Atlantic varieties at the seedling and budding stages was notably different under two types of N stress. Under two types of N stress, stu-miR396-5p was down-regulated in Yanshu4 in the seedling-stage and shoot-stage roots, and up-regulated in seedling-stage roots and shoot-stage leaves; stu-miR482a-3p was up-regulated in the seedling and shoot stages. The expression of stu-miR8036-3p was up-regulated in the leaves and roots at the seedling and budding stages, and down-regulated in roots under both types of N stress. The gene expressing the key enzyme involved in N metabolism, StNiR, and the stu-miR396-5p luciferase assay reporter gene had a strong regulatory relationship with each other. This study provides candidate miRNAs related to nitrogen metabolism and highlights that differential miRNAs play a key role in nitrogen stress in potato, providing insights for future research on miRNAs and their target genes in nitrogen metabolic pathways and breeding nitrogen-efficient potatoes.

Role and Responsibility of Sustainable Chemistry and Engineering in Providing Safe and Sufficient Nitrogen Fertilizer Supply at Turbulent Times

Role and Responsibility of Sustainable Chemistry and Engineering in Providing Safe and Sufficient Nitrogen Fertilizer Supply at Turbulent Times

Diff erent Levels of Nitrogen Fertilizer in Nursery Stage Positively Aff ect the Activity of Defense-related Enzymes and Resistance of Tobacco Plant to Phytophthora nicotianae

Black shank caused by Phytophthora nicotianae is a serious threat to the production of better-quality fl ue-cured tobacco. Protein’s are executors of plant functions and most disease resistance mechanisms in plants are related to differential expression of proteins. In our previous study, 17 different proteins induced by P. nicotianae were screened out through proteomics analysis. In this study, we evaluated the effect of three different levels of nitrogen fertilizer (High, medium, and low) at the seedling stage on the expression of these proteins, physiological response of fl ue-cured tobacco, and occurrence of black shank disease. Results of this study showed that before and after inoculation of P. nicotianae, the activity of defense-related enzymes except for MDA contents in tobacco plants grown under low- nitrogen level was higher than tobacco plants grown under the high-nitrogen level at seedling stage. Through analysis of 17 different proteins, we found the expression of 12 proteins (three proteins involved in photosynthesis, six proteins involved in oxidative phosphorylation, one protein involved in tricarboxylic acid cycle, one heat shock protein, and one 14-3-3 protein) were up-regulated in tobacco seedlings raised under low nitrogen level. However, the expression of fi ve pathogenesis-related proteins was not detected. This study highlights the effect of effi cient use of nitrogen fertilizer during the nursery growing stage for producing healthy tobacco seedlings. It is concluded that a proper supply of nitrogen fertilizer at the seedling stage ensures the quality production of tobacco seedlings and reduces the incidence of black shank disease.

Nitrogen response of two corn cultivars grown alone or intercropped in a soybean succession system in the Brazilian cerrado

The most widely used production systems in the Cerrado region are soybean (Glycine max)-corn (Zea mays) and soybean-corn intercropped with ruzigrass [Urochloa ruziziensis (Syn. Brachiaria ruziziensis)]. Thus, these systems may require a higher supply of mineral nitrogen (N) fertilizer. Therefore, the objective of this study was to evaluate the agronomic traits of two corn cultivars grow in the second-crop harvest in different environments, production systems, and N application rates in an Oxisol in the Cerrado region of Mato Grosso do Sul. The experimental design was a randomized block arranged in a split-split plot with three replicates. Plots consisted of two environments (UFMS 1 and UFMS 2), subplots consisted of two production systems [corn alone (monoculture) or corn intercropped with U. ruziziensis, and sub-subplots of five N application rates in topdressing (0, 40, 80, 120, or 160 kg N/ha). Urea was used as the source of N (45% N), and it was applied 30 days after emergence (DAE). Two corn cultivars (NS50 and Invictus Viptera 3) were used. During the flowering period of corn (i.e., after the emergence of female inflorescence), the relative chlorophyll index, leaf N concentration, plant height, and ear insertion height were recorded. At physiological maturity, the ear insertion height, ear length, number of grain rows per ear, number of grains per row, ear diameter, mass of one thousand grains, and grain yield were measured. The corn grain yield is lower in the system intercropped with U. ruziziensis when compared to the cultivation of corn alone (monoculture). In addition, the environment with greater soil base saturation and N availability (UFMS 2) results in a distinct response for the corn cultivar used; thus, a greater grain yield is expected from cultivar Viptera 3 in this environment. The maximum agronomic efficiency for corn grain yield is obtained with 102 to 123 kg N/ha for the Viptera 3 and NS50 PRO cultivars, respectively.

The Effect of Nitrogen Fertilizer and Water Supply Levels on the Growth, Antioxidant Compounds, and Organic Acids of Baby Lettuce

Applications of solutions with various organic acids have been widely demonstrated as effective disinfectants on lettuce. However, agronomic techniques of improving the concentration of internal organic acids in lettuce are not well investigated. Hereon, changes in growth, antioxidants, and organic acids of baby lettuce (Lactuca sativa L. var. longifolia) resulting from different levels of nitrogen fertilizer (0.10, 0.14, 0.18, or 0.22 g/5 kg soil) and water supply (300, 600, or 900 mL) were investigated. The pot experiment was conducted under a net house at North-West University (Mafikeng Campus), South Africa. Data on growth parameters (number of leaves and leaf area) and chlorophyll concentration were sampled weekly until leaf organic acids (citric, malic, and tartaric), total antioxidant compounds (TAO), as well as dry matter content, were measured at harvest. Reducing the amount of water supplied to baby lettuce significantly (p &lt; 0.05) increased the chlorophyll concentration, leaf area, TAO, citric acid, and malic acid. The number of leaves and the leaf tartaric acid concentrations were increased by increasing the treatment levels. It was conclusive that decreasing water supply increases the organic acids regardless of the nitrogen level.

ANALYSIS OF PROTEIN IN WHEAT GRAIN

Wheat is one of the most important cereal crops grown with highest demand. Nitrogen content that enables the protein in the grain is necessary for baking and processing quality. The importance of wheat protein and its functionality in bakery products are well discussed in the given topic. This Study was carried out to study the effect of nitrogen fertilizer supply and its implications on bread wheat variety in the baking process. Dumas method is used for estimating the protein content in the bread variety that is grown in two different nitrogen fertilizers supply with 100kg/ha and 350kg/ha respectively. The results clearly depict the highest growth of bread wheat variety which was grown in 350kg/ha of nitrogen supply has high amount of protein content. Wheat is the best source of carbohydrates and the proteins present in are gliadin and glutenin which are responsible to provide viscoelastic properties in the bakery products. Functionality of the bakery products are well discussed in the introduction part. The result includes test values and graphs have been plotted based on the comparison of protein present in bread. In the discussion section the differences and effects of protein in processing of foods are analysed against similar other research works.

Stomatal conductance limited the CO2 response of grassland in the last century

BackgroundThe anthropogenic increase of atmospheric CO2 concentration (ca) is impacting carbon (C), water, and nitrogen (N) cycles in grassland and other terrestrial biomes. Plant canopy stomatal conductance is a key player in these coupled cycles: it is a physiological control of vegetation water use efficiency (the ratio of C gain by photosynthesis to water loss by transpiration), and it responds to photosynthetic activity, which is influenced by vegetation N status. It is unknown if the ca-increase and climate change over the last century have already affected canopy stomatal conductance and its links with C and N processes in grassland.ResultsHere, we assessed two independent proxies of (growing season-integrating canopy-scale) stomatal conductance changes over the last century: trends of δ18O in cellulose (δ18Ocellulose) in archived herbage from a wide range of grassland communities on the Park Grass Experiment at Rothamsted (U.K.) and changes of the ratio of yields to the CO2 concentration gradient between the atmosphere and the leaf internal gas space (ca – ci). The two proxies correlated closely (R2 = 0.70), in agreement with the hypothesis. In addition, the sensitivity of δ18Ocellulose changes to estimated stomatal conductance changes agreed broadly with published sensitivities across a range of contemporary field and controlled environment studies, further supporting the utility of δ18Ocellulose changes for historical reconstruction of stomatal conductance changes at Park Grass. Trends of δ18Ocellulose differed strongly between plots and indicated much greater reductions of stomatal conductance in grass-rich than dicot-rich communities. Reductions of stomatal conductance were connected with reductions of yield trends, nitrogen acquisition, and nitrogen nutrition index. Although all plots were nitrogen-limited or phosphorus- and nitrogen-co-limited to different degrees, long-term reductions of stomatal conductance were largely independent of fertilizer regimes and soil pH, except for nitrogen fertilizer supply which promoted the abundance of grasses.ConclusionsOur data indicate that some types of temperate grassland may have attained saturation of C sink activity more than one century ago. Increasing N fertilizer supply may not be an effective climate change mitigation strategy in many grasslands, as it promotes the expansion of grasses at the disadvantage of the more CO2 responsive forbs and N-fixing legumes.

A mechanochemical preparation, properties and kinetic study of kaolin–N, P fertilizers for agricultural applications**

Abstract Solvent-free ball milling was used to activate kaolin, a trioctahedral clay material, with diammonium phosphate[(NH4)2HPO4] to serve as a fast-acting phosphorus and nitrogen releasing fertilizer. Different tests on a mixture of 3:1 weight ratio of kaolin: (NH4)2HPO4 were performed to analyze the level of incorporation of (NH4)2HPO4 in the kaolin and the degree of liberation of NH 4 + {\rm{NH}}_4^ + and PO 4 3 − {\rm{PO}}_4^{3 - } ions into solution. The experimental mill speeds were varied from 200 to 700 rpm rotational rates for a fixed period of 2 hours. Several milling periods of 1, 2, and 3 h. were studied at the fixed milling speed of 600 rpm. To explain the properties of activated materials and to understand the purpose behind the simpler disintegration of phosphorus, several analytical methods such as FT-IR, TGA-DTG and Ion chromatography (IC) were used. The proposed procedure was environmentally friendly, and it helped to maintain a balanced supply of nitrogen and phosphorus fertilizer for agriculture's long-term development by offsetting some of the existing high-cost chemical fertilizer. The results demonstrated that the mechanochemical reaction could yield an intercalated form of kaolin that is a transmitter of N and P sources in fertilizers.

Research Article The supply of nitrogen fertilizer in wheat to the highest environmental quality with satisfactory yield

Research Article The supply of nitrogen fertilizer in wheat to the highest environmental quality with satisfactory yield

Graphical analysis of nitrogen and sulfur supply on yield and related traits of canola in eastern Canada

Profitable canola production depends upon an adequate supply of nitrogen (N) and sulfur (S) fertilizer. However, agricultural soils in eastern Canada seldom receive S fertilizer and rely on inherent S supply from biogeochemical and anthropogenic sources, which could be a yield-limiting factor for canola. The objective of this study was to document N × S fertilizer interactions to develop site-specific best management practices for canola production in eastern Canada. Factorial field experiments were conducted for four consecutive cropping seasons at five locations across eastern Canada. The N × S and N × S × environment interactions on seed yields and yield-related traits were visualized with the graphical analytical genotype and genotype-by-environment biplot tool. The highest seed yield was achieved with 150 kg N ha−1 together with 20–40 kg S ha−1 in 15 of the 19 test site-years. Seed yield was closely related to harvest index and number of seeds pod−1. Fertilizing canola with 20 kg S ha−1 enhanced the nitrogen use efficiency (NUE) of canola receiving 75 kg N ha−1, but the benefit of S fertilizer on NUE was negligible when N fertilizer rates increased to 150 kg N ha−1. Since canola yield response to fertilizer inputs varied from one site to another, due to the variation in environmental and soil conditions, we conclude that N × S fertilizer recommendations for canola production need to be developed on a site-specific basis in eastern Canada.

Effects of nitrogen fertilizer rates and waterlogging on leaf physiological characteristics and grain yield of maize

ABSTRACT Nitrogen fertilizer supply and use play a vital role in determining crop growth and yield. However, the effects of nitrogen fertilizer levels on plant growth under waterlogging conditions remain elusive. The objective of this study was to investigate the effects of nitrogen fertilizer rates (0, 90, 180, 270, and 360 kg N ha−1, designated N0, N1, N2, N3, and N4, respectively) on leaf physiological characteristics and grain yield of maize (Zea mays L.) under two water regimes (WW or well-watered through the maize grown season and WL or waterlogged for six days at the sixth-leaf stage). Overall, in comparison to WW, WL treatment showed a reduction in the following traits, at all nitrogen rates: plant height, leaf area index, SPAD value, superoxide dismutase, peroxidase, and catalase activity, net photosynthetic rate (P n), transpiration rate, stomatal conductance, ears per ha, kernels per ear, 1,000-kernel weight, and grain yield. Moreover, the majority of the above parameters increased with the increase in nitrogen application rate under WL, as a result of the enhanced available nitrogen content at higher nitrogen application rates. Therefore, increasing supply levels of nitrogen fertilizer could improve antioxidant enzyme activity and P n, consequently producing increased maize grain yield under waterlogged conditions.

Soil fertility characteristics and their influencing factors in tea plantations of Jiangxi Pro-vince, China

To investigate soil fertility status and characteristics of typical tea plantations, we selec-ted 372 typical tea plantations of 21 areas across Jiangxi Province and analyzed the soil nutrient, spatial data, and their correlations with topography, soil type, elevation and plantation age. The results showed that soil pH, organic matter, alkaline nitrogen, available phosphorus, available potassium, total nitrogen, total phosphorus and total potassium of tea plantation in Jiangxi reached 53.9%, 60.1%, 56.1%, 22.9%, 38.5%, 43.7%, 11.1% and 95.5% of indices of high fertility, high efficiency and high yield tea plantation, respectively, with the available phosphorus showing a strong variation. Soil available copper, zinc, iron, manganese and boron reached 76.3%, 74.2%, 96.8%, 73.1% and 0.0% of the first-class standards for soil trace elements, respectively. Tea plantations with highest soil fertility located in central Jiangxi, followed by northeastern and northwestern Jiangxi, and lowest in southern Jiangxi. Soil pH was significantly positively correlated with organic matter, alkaline nitrogen, available phosphorus, available potassium, total nitrogen and total phosphorus but not for total potassium. For different topography, soil fertility was highest in the flat land, followed by the high mountains, and lowest in the mountains and hills. Across different soil types, soil fertility was higher in paddy soil, sandy soil and mountain yellow brown soil, followed by yellow soil, red-yellow soil and purple soil, and lowest in red soil. Soil pH, organic matter and total potassium increased while available phosphorus decreased with altitude. The organic matter, alkaline nitrogen, available phosphorus, total nitrogen and total phosphorus increased, but soil pH decreased with time. In summary, soil fertility of tea plantations in Jiangxi Province was generally good, with high organic matter, total potassium, available copper, zinc, iron and manganese. However, soil was acidic, available phosphorus and total phosphorus content was low, available boron was seriously limited. We suggest increase soil pH and potassium supply in central Jiangxi, increase potassium and nitrogen fertilizer supply in northeastern Jiangxi, increase organic matter and phosphorus fertilizer supply in northwestern Jiangxi, and increase nitrogen, phosphorus and potassium supply combined with organic fertilizers in southern Jiangxi. High mountain tea plantations should enhance available phosphorus and potassium supply. Mountain tea plantations should enhance nitrogen and phosphate supply. Tea plantations with red and yellow soil should increase pH and total potassium supply. Tea plantations with red soil should apply nitrogen, phosphorus and potassium fertilizers combined with organic fertilizers. Tea plantations with yellow soil and mountain yellow brown soil required additional phosphorus supply, and tea plantations with purple soil should increase soil organic matter supply. Tea plantations need to increase dolomite powder, physiological alkaline fertilizers and organic fertilizers to prevent soil acidification.

The Response of Teff [Eragrostis teff (Zucc) Trotter] to Nitrogen Fertilizer Application and Row Spacing: A Review

Teff [ Eragrostis tef (Zucc) Trotter] is one of the most important crops in Ethiopia. It ranks the first among cereals in the country in area coverage and second in the production volume. Despite its importance, the production and productivity of this particular crop are highly constrained by several biotic and abiotic factors. Some of the factors contributing to the low yield of teff are low soil fertility and suboptimal use of mineral fertilizers in addition to weeds, old method of seed sowing, erratic rainfall distribution in lower altitudes, method of row planting, lack of high yielding cultivars, lodging, water-logging and late planting of the crop which exposes it to moisture stress. The productivity of teff is very low compared to other major cereal crops. On the other hand, under conditions where most growth requirements are available and inorganic matter rich soils, the application of fertilizers without knowing its fertility status causes yield and fertilizer losses. Likewise, producers do not give attention to teff row spacing, even if it has an advantage of shorter maturity days, highest plant height, highest panicle length, and the number of tillers and less lodging index percentages. Since, grain yield increased with the increase of plant height, panicle length and number of tillers per plant. Therefore, the optimum supply of nitrogen fertilizer and medium row spacing increased the grain yield of crops. Keywords: teff; inter-row spacing; and grain yield DOI : 10.7176/ALST/78-02 Publication date: February 29 th 2020