Type Of Nitrogen Fertilizer Research Articles

Coupling effects of irrigation amount and nitrogen fertilizer type on grain yield, water productivity and nitrogen use efficiency of drip-irrigated maize

Agricultural production is facing the risk of severe water shortage, serious non-point source pollution and low water productivity (WP) and nitrogen use efficiency (NUE). It is a major challenge to achieve environmentally friendly production of maize with high WP and NUE. A two-year field experiment with three irrigation levels of W1 (60% ETc, ETc is the crop evapotranspiration), W2 (80% ETc) and W3 (100% ETc), and three nitrogen (N) fertilizer types of urea (U), slow-release N fertilizer (SRF) and urea blended with slow-release N fertilizer (UNS) was conducted in 2019 and 2020, so as to quantify their impacts on the maize dry matter, N uptake and remobilization, grain yield, WP, NUE and residual soil NO3−-N. The results showed that W2 and W3 significantly increased total dry matter (8.0% and 14.7%), grain yield (19.4% and 33.0%), and NUE (1.5% and 2.2%) compared with W1. Total N uptake of maize declined by 23.2% and 9.6% under W1 and W2, leading to 11.9% and 5.8% increased of soil NO3−-N, respectively. Compared with U, UNS increased post-silking N uptake by 19.1%, thereby enhancing grain yield by 18.3%. Compared with SRF, UNS increased N remobilization from vegetative organs to grains by 15.0%, thereby resulting in 2.3% increase in grain yield. Under the same irrigation amount, UNS and SRF improved WP and NUE compared with U. W3SRF obtained the highest grain yield, with increases in grain yield by 2.4–58.8% compared with other treatments, while there was no significant difference between W3SRF and W3UNS. More importantly, UNS significantly increased grain yield and alleviated the impact of water stress on maize production under W1 and W2. In conclusion, UNS could stabilize grain yield under water-stressed conditions, while SRF could increase grain yield under full irrigation.

Nitrous Oxide Emission Fluxes in Coffee Plantations during Fertilization: A Case Study in Costa Rica

The main source of N2O emissions is agriculture, and coffee monocultures have become an important part of these emissions. The demand for coffee has increased in the last five decades. Thus, its production in agricultural fields and the excess of fertilizers have increased. This study quantified N2O emissions from different dose applications and types of nitrogen fertilizer in a region of major coffee production in Costa Rica. A specific methodology to measure N2O fluxes from coffee plants was developed using Fourier-transform infrared spectroscopy (FTIR). Measurements were performed in a botanical garden in Germany and plots in Costa Rica, analyzing the behavior of a fertilizer in two varieties of coffee (Catuai and Geisha), and in a field experiment, testing two types of fertilizers (chemical (F1) and physical mixture (F2)) and compost (SA). As a result, the additions of synthetic fertilizer increased the N2O fluxes. F2 showed higher emissions than F1 by up to 90% in the field experiment, and an increase in general emissions occurred after a rain event in the coffee plantation. The weak levels of N2O emissions were caused by a rainfall deficit, maintaining low water content in the soil. Robust research is suggested for the inventories.

Application of calcium nitrate with phosphorus promotes rhizosphere alkalization in acid subsoil

AbstractCombatting subsoil acidity is a challenge as the incorporation of lime in subsurface layers may not be economically feasible. The use of nitrate to facilitate plant excess anion uptake has shown the potential to increase soil pH. A column experiment was carried out to demonstrate this root‐induced alkalization in various depths in an acid soil with pH 4.28 (0.01 M CaCl2). It consisted of two types of nitrogen (N) fertilizers (urea and Ca(NO3)2, both at 5 atom% 15N enrichment) banded at a depth of 0–10 cm, 10–20 cm or 20–30 cm, with phosphorus (P) fertilizer (NaH2PO4) at 150 mg P per column either applied to the N layers (N+P) or evenly mixed into the remaining layers without N addition (N‐P). Aluminium‐tolerant wheat (ET8) was used as test plants, receiving an initial N dose of 60 mg kg−1 soil at sowing and an additional dose of 30 mg kg−1 every 10 days from 40 days after sowing. Plants had a total N supply of 90 mg N kg−1 at 50 days and 180 mg N kg−1 at 80 days after sowing. The N+P treatments increased plant N uptake and increased rhizosphere and bulk soil pH. Nitrate placement increased pH of treated layers by up to 0.4 and 0.2 units in the rhizosphere and bulk soils, respectively, compared with the control at Day 80. Rhizosphere alkalization was greater with deeper N+P treatments as these encouraged the proliferation of deeper roots in the treated layer. The form of N and the application method of P fertilizer had no effect on shoot biomass over 80 days of growth. The N+P treatments had 7% higher 15N recovery of fertilizer in plants than the N‐P treatments. The current study also showed that P fertilizer enhanced rhizosphere alkalization induced by calcium nitrate. The results suggest that the use of nitrate fertilizer with P treatments can facilitate alkalization of acid subsoils.Highlights Phosphorus facilitates amelioration of subsurface soil acidity with nitrate fertilizer Placement of nitrate induces alkalization of acid soil at various depths Combined addition of nitrate and P at depth enhances nitrate uptake by wheat Balanced nutrient supply enhances excess anion uptake and rhizosphere alkalization

Effects of Urea-Ammonium Nitrate Solution on Yield, N2O Emission, and Nitrogen Efficiency of Summer Maize Under Integration of Water and Fertilizer.

In order to clarify the effects of urea-ammonium nitrate solution (UAN) on the yield, nitrogen-use efficiency (NUE), and N2O emissions of summer maize under the condition of water and fertilizer integration, different types of nitrogen fertilizer were selected, namely, ordinary urea (urea) and UAN. Our results showed that the application of UAN was beneficial to improve the dry matter accumulation and the distribution of summer maize. Compared with urea treatment, the total nitrogen accumulation of UAN treatment was increased by 15.8%, and the harvest index was increased by 5.5%. The partial productivity, agronomic use efficiency, and recovery rate of nitrogen for UAN treatment were also increased by 9.1, 19.8, and 31.2%, respectively, compared to those of urea treatment. The soil nitrogen dependence rate treated with UAN was significantly decreased by 13.6%, compared to that of urea treatment. In addition, UAN was beneficial to reduce N2O emissions. The N2O warming potential (GWPN2O) and N2O greenhouse gas intensity (GHGIN2O) of urea treatment were 39.3 and 52.4% higher, compared to those of UAN treatment. The improvement of dry matter accumulation and distribution and nitrogen efficiency for UAN treatment were beneficial to increase the grain yield by 9.1%, compared to that of urea treatment. In conclusion, under the fertigation, the application of UAN favors higher yield and nitrogen uptake, with less soil nitrogen residue, higher NUE, and better environmental effect.

English

Optimum nitrogen fertilization from the right source is the most important production factors for higher grain yield of wheat. Study to investigate the effect of type and rate of Nitrogen fertilizer on yield of bread Wheat was conducted in Ofla and Endamehoni districts of northern Ethiopia in 2017 and 2018 main cropping season. The treatments consists four levels of different sources of nitrogen fertilizer (Prilled urea, granular urea, urea super granule and UREAstabil) each with three application rates (46, 69 and 92 kg N ha−1) and one control (without any N fertilizer application) laid down in a randomized complete block design replicated three times.  Grain yield of was affected significantly to the application rates and source of nitrogen fertilizer at Adigolo and Mekan districts of Ofla and Endamehoni respectively.  The highest grain yield of 5.11 and 4.08 tha-1 was obtained from application 92 and 69 kg N ha-1 of UREAstabil at Adigolo and Mekan districts respectively.  In both Adigolo and Mekan districts, grain yield of wheat showed that a linear increase with increasing rate of N fertilize while,  application of 46 kg N ha-1 from UREAstabil reaches optimum agronomicaly and economically for the study areas. Key words: Prilled urea, super granular urea, granular urea, UREAstabil.

The combination of different nitrogen fertilizer types could promote rice growth by alleviating the inhibition of straw decomposition

AbstractStraw return plays an important role in the improvement of farmland ecological environments, increasing soil fertility, crop quality, and yield. However, in the early growth of rice (Oryza sativa L.), straw decomposition and rice growth may be inhibited by suboptimal carbon/nitrogen (C/N) ratios. We, therefore, explored methods that could alleviate the inhibition of straw decomposition using different combinations of ammonium bicarbonate and compound fertilizer. No fertilizer (CK) and compound fertilizer (S0) were used as the control. The ratios of added ammonium bicarbonate were 10% (S1), 20% (S2), 30% (S3), and 40% (S4), respectively. Compared with the S0 treatment, the S2 treatment accelerated straw decomposition, promoted the early growth of tillers and roots, and improved the leaf area index, dry matter accumulation, and N use efficiency (apparent N utilization, agronomic N utilization, and partial factor productivity increased by 4.05‒19.48% in two years). Moreover, panicle number, filled‐grain percentage, and 1000‐grain weight were significantly higher in the S2 treatment than other treatments. The grain yield of S2 treatment was significantly higher than that of S0 treatment by 4.06% (2019) and 5.66% (2020). Regression analysis revealed that the optimal ratios of ammonium bicarbonate for increasing straw decomposition and grain yield were relatively close, 16.27% and 14.60%, respectively. These results suggest that compared with conventional fertilization method (S0), the 20% treatment is a more effective fertilization method that prevents inhibition of straw decomposition, promoting rice growth and yield, and improving nitrogen (N) use efficiency.

НАИБОЛЕЕ РАСПРОСТРАНЁННЫЕ ОРГАНИЗМЫ-БИОИНДИКАТОРЫ ПЛОДОРОДИЯ ПОЧВ СЕВЕРА

The research was conducted in the Tambov and Lipetsk regions. A comparative assessment of the sensitivity of the most common and publicly available bioindicators of soils in the northern part of the Central Chernozem region was carried out. Among cereals and leguminous crops, simply and alfalfa are very sensitive to changing the acidity of the soil. From cruciferous vegetable plants, lettuce and radish react well to the formation of humus-rich soils and the change of soil type in the rosette phase during the growth of the root crop (the biochemical composition of the root crop changes). Leaf lettuce and spinach react sensitively not only to the type of nitrogen ferti-lizer, the presence of chlorine, but also to the dose of nitrogen for the active substance. The cu-cumber reacts sensitively to different levels of easily hydrolyzed nitrogen in the soil by the time the first whiskers are formed. Winter cereals (wheat and triticale) are good bioindicators for dif-ferent soil bonuses and their biomass shows a different attitude to the soil from two zones of apple orchards – row spacing and trunk strips. Barley is also responsive to soil bonitet. All its above-ground organs change the content of the common forms of nitrogen, phosphorus and potassium when the soil conditions change, and only in the ear of these elements of nutrition remain in the optimal range. Apple seedlings with their aboveground biomass, the number of leaves and their water regime react to changes in the properties of the humus horizon, soil fatigue and the change of the soil horizons themselves. In response to an increase in the content of humus, potassium, and manganese in the soil and a change in pHKCl in the leaves of clonal apple rootstocks PB-9 and 62-396, the amount of potassium, phosphorus, calcium, and magnesium changes. Rootstock 62-396 sensitively changes the content of anthocyanins, chlorophyll and carotenoids in the leaves in re-sponse to the change in soil type. Yeast and mold fungi reduce their number when the pesticide load on the soil increases. The complex of cellulose-decomposing soil microorganisms reacts sen-sitively to the change of the soil horizon, soil type and anthropogenic transformation during the development of land for apple orchards.

Varied farm-level carbon intensities of corn feedstock help reduce corn ethanol greenhouse gas emissions

A reduction in the overall carbon intensity (CI) of a crop-based biofuel can be achieved by cutting down the CI of the biofuel’s feedstock, which in turn correlates significantly to agricultural management practices. Proposals are being made to incentivize low-carbon biofuel feedstocks under U.S. fuel regulatory programs to promote sustainable farming practices by individual farms. For such an incentive scheme to function properly, robust data collection and verification are needed at the farm level. This study presents our collaboration with U.S. private sector companies to collect and verify the corn production data necessary for feedstock-specific CI calculation at the farm level, through a carefully designed questionnaire, to demonstrate the practicality and feasibility of data collection at scale. We surveyed 71 farms that produced 0.2 million metric tons of corn grain in 2018 in a Midwestern U.S. state to obtain information on key parameters affecting corn ethanol feedstock CI, such as grain yields, fertilizer/chemical application rates, and agronomic practices. Feedstock-specific CI was calculated in the unit of grams (g) CO2 equivalent (CO2e) of greenhouse gases per kilogram (kg) of corn produced. Results showed large CI variations—from 119 to 407 g CO2e kg−1 of corn—due to the farm-level inventory, while the production-weighted average CI for all surveyed farms was 210 g CO2e kg−1, comparable to the national average CI of 204 g CO2e kg−1. The nitrogen fertilizer type applied and rate were identified as key factors contributing most to CI variations at the farm level. The estimated N2O emissions from fertilizer and biomass nitrogen inputs to soil accounted for 51% of the overall farm-level CI and therefore need to be better monitored at farm level with high resolution. We concluded that this feedstock-specific, farm-level CI evaluation has the potential to be used to incentivize low-carbon feedstock for biofuel production.

Life Cycle Assessment and Soil Nitrogen Balance of Different N Fertilizers for Top Dressing Rye as Energy Crop for Electricity Generation

Nitrogen fertilizers have been identified in energy crops LCAs as the main contributors to global warming, as well as to many other environmental impacts. The distinct production process and application emissions of nitrogen fertilizer types for top dressing produce different GHG savings when energy crops value chains are compared to fossil energy alternatives. In this study, three types of fertilizers (calcium ammonium nitrate, urea and ammonium sulphate) at N top dressing rates of 80 kg N/ha are used to grow rye for electricity generation under the conditions of the Continental Mediterranean climate of central-northern Spain. Complete LCAs for the whole value chain based on real data were performed in conjunction with soil nitrogen balances (SNBs) to assess the accomplishment of European Union (EU) GHG savings sustainability criteria, as well as the sustainability of fertilization practices for soil nitrogen stocks. The results obtained can provide interesting insights for policy making, since calcium ammonium nitrate, the most common fertilizer for rye crops, led to 66% GHG savings, as opposed to the 69% achieved when applying urea and 77% when ammonium sulphate was used. Nevertheless, the three fertilizers produced annual soil deficits greater than 50 kg N/ha. In order to ensure savings above 80%, as required by the EU sustainability criteria, and sustainable SNBs, additional optimization measures should be taken at key points of the value chain.

Dry Matter Yield of Maize (Zea mays L.) as an Indicator of Mineral Fertilizer Efficiency.

This study presents the results of 3-year field trials, whose purpose was to assess the dynamics of dry matter accumulation by maize depending on the placement depth of a two-component (NP) mineral fertilizer in the soil layer, type of nitrogen fertilizer and date of its application. Weather conditions, mainly thermal in the early growing season, had a significant effect on maize responses to placement depth of phosphorus starting dose in the soil profile. In the initial stage of maize development, the temperature determined plant growth to a significantly higher extent than the sum of rainfall. The dry matter yield of ears and whole plants showed a clear reaction to starter phosphorus fertilization, but the effect of the depth of fertilizer placement varied over the years, indicating a depth of 5 cm and 10 cm as advisable and recommended for agricultural practice. The PFPFN (partial factor productivity of fertilizer nitrogen) and PFPFP (partial factor productivity of fertilizer phosphorus) indices confirmed the significant effect of fertilizer (NP) placement in the soil profile, indicating row fertilizer application (regardless of the depth) as recommended to improve the efficiency of maize fertilization. The SPAD (soil plant analysis development) leaf greenness index turned out to be a sensitive indicator of maize response to fertilizer (NP) placement depth in the soil profile.

Impact of levels of nitrogen fertilizer and types of irrigation water on yield and yield components of barley crop

A pot experiment was carried out at the Experimental Farm, Faculty of Agriculture, South Valley University, Qena, Egypt during the 2015-2016 and 2016-2017 seasons to study the effect of nitrogen fertilizer levels and types of irrigation water (W1; Tap water only, W2; manipulated wastewater with sandy filter, W3; manipulated wastewater with nano-titanium dioxide + sandy filter and W4; a mixture of treated wastewater with nano-titanium dioxide and sandy filter + tap water) on growth, yield and its attributes of barley cv. Giza 2000. A randomized complete block design (RCBD) using a split-plot arrangement with four replications was used. The main plot was four different levels of nitrogen fertilizer and the sub-plot were four different types of irrigation water. The seeds of above mentioned variety were used in the pot experiments. The highest mean values of plant height, number of tillers plant-1, spike length, number of grains spike-1, spike weight, biological yield plant-1 and grain yield plant-1 were obtained from high level of nitrogen (60 kg N fed-1). Also, the highest values of above traits were obtained from irrigation with treated wastewater with nano-titanium dioxide and sandy filter + tap water (W4). It could be concluded that under the conditions of the experiment, application of high levels of nitrogen (N60) under irrigation with treated wastewater with nano-titanium dioxide and sandy filter+ tap water (W4) is recommended.

Effects of mechanized deep placement of nitrogen fertilizer rate and type on rice yield and nitrogen use efficiency in Chuanxi Plain, China

This paper investigates the yield and nitrogen use efficiency (NUE) of machine-transplanted rice cultivated using mechanized deep placement of N fertilizer in the rice–wheat rotation region of Chuanxi Plain, China. It provides theoretical support for N-saving and improves quality and production efficiency of machine-transplanted rice. Using a single-factor complete randomized block design in field experiments in 2018 and 2019, seven N-fertilization treatments were applied, with the fertilizer being surface broadcast and/or mechanically placed beside the seedlings at (5.5±0.5) cm soil depth when transplanting. The treatments were: N0, no N fertilizer; U1, 180 kg N ha–1 as urea, surface broadcast manually before transplanting; U2, 108 kg N ha–1 as urea, surface broadcast manually before transplanting, and 72 kg N ha–1 as urea surface broadcast manually on the 10th d after transplanting, which is not only the local common fertilization method, but also the reference treatment; UD, 180 kg N ha–1 as urea, mechanically deep-placed when transplanting; M1, 81.6 kg N ha–1 as urea and 38.4 kg N ha–1 as controlled-release urea (CRU), mechanically deep-placed when transplanting; M2, 102 kg N ha–1 as urea and 48 kg N ha–1 as CRU, mechanically deep-placed when transplanting; M3, 122.4 kg N ha–1 as urea and 57.6 kg N ha–1 as CRU, mechanically deep-placed when transplanting. The effects of the N fertilizer treatments on rice yield and NUE were consistent in the 2 yr. With a N application rate of 180 kg ha–1, compared with U2, the N recovery efficiency (NRE), N agronomic use efficiency (NAE) and yield under the UD treatment were 20.6, 3.5 and 1.1% higher in 2018, and 4.6, 1.7 and 1.2% higher in 2019, respectively. Compared with urea alone (U1, U2 or UD), the NRE, NAE and yield achieved by M3 (combined application of urea and controlled-release urea) were higher by 9.2–73.3%, 18.6–61.5% and 6.5–16.5% (2018), and 22.2–65.2%, 25.6–75.0% and 5.9–13.9% (2019), respectively. Compared with M3, the lower-N treatments M1 and M2 significantly increased NRE by 4.0–7.8% in 2018 and 3.1–4.3% in 2019, respectively. Compared with urea surface application (U1 or U2), the yield under the M2 treatment was higher by 4.3–12.9% in 2018 and 3.6–10.1% in 2019, respectively. Compared with U2, the NRE and NAE under the M2 treatment was higher by 36.9 and 36.3% in 2018, and 33.2 and 37.4% in 2019, mainly because of higher N uptake. There was no significant difference in the concentration of nitrate in the top 0–20 cm soil under U1, U2 and M2 treatments during the full heading and maturity stages. During the full heading stage, U2 produced the highest concentration of nitrite in 0–20 cm and 20–40 cm soil among the N fertilizer treatments. In conclusion, mechanized deep placement of mixed urea and controlled-release urea (M2) at transplanting is a highly-efficient cultivation technology that enables increased yield of machine-transplanted rice and improved NUE, while reducing the amount of N-fertilization applied.

Reaction of barley to top-dressing with different types of nitrogen fertilizer

The study was carried out to investigate effect of mineral (CAN) and organo-mineral (OMF) top-dress nitrogen fertilizers on physiological and morphological parameters in three barley cultivars. The study revealed significant differences in the reaction of the cultivars in magnitude and direction of the yield structure elements. CAN had smaller effect on the studied parameters than OMF. CAN had no effect on grain yield and straw mass. Only for the cv. Novichok, there was an increase in grain weight from the main ear (15%), the length of the main ear (15%), the 1000-grain weight (2.9%). OMF led to increase grain yield in the cv. Novichok (43%), Pamiaty Rodinoy (16%), and did not change in the cv. Rodnik Prikamya. Only the cv. Novichok has increased the grain mass from the main ear (17%). The length of the main ear increased in the cv. Novichok (13%), Pamiaty Rodinoy (11%) but decreased in the cv. Rodnik Prikamya (7.5%). The influence of OMF increased the 1000-grain weight in the cv. Novichok (4.9%) and Pamiaty Rodinoy (2.5%), but decreased in the cv. Rodnik Prikamya (1.5%). Statistically differences were revealed in reaction of pigment complexes of flag and second leaves in all cultivars.

Greenhouse gas emissions in agricultural cultivated soils using animal waste-based digestates for crop fertilization

AbstractAgricultural waste contributes significantly to greenhouse gas (GHG) emissions if not adequately recycled and sustainably managed. A recurring agricultural waste is livestock waste that has consistently served as feedstock for biogas systems. The objective of this study was to assess the use of animal waste digestate to mitigate GHG emissions in agricultural fields. Wheat (Triticumspp. L.) was fertilized with different types of animal waste digestate (organic fertilizers) and synthetic nitrogen fertilizer (inorganic fertilizer). The 170 kg N/ha presented in digestates were split fertilized at an application rate of 90 and 80 kg N/ha. Emissions of GHGs (carbon dioxide (CO2), methane (CH4) and nitrous oxide (N2O)) were monitored directly by a static chamber system. The soil and environmental variables were measured to determine their influence on GHG emissions. Emission peaks in N2O and CO2after the first application of fertilizers with the emissions flattening out over the cultivating season while CH4emission was negligible with no apparent patterns observed. Results showed individual and cumulative emissions of CO2, CH4and N2O from the digestates were relatively low and digestate fertilization could be an efficient method for reducing GHGs from agricultural sources in temperate climate conditions.

옥수수 재배지 아산화질소 배출에 대한 질소비료와 바이오차 시용 효과

옥수수 재배지 아산화질소 배출에 대한 질소비료와 바이오차 시용 효과

Impacts of Nitrogen Application on Ammonia Volatilization During Maize Season in Northern China

Ammonia volatilization is one of the major paths of nitrogen (N) loss and may exert a substantial impact on air quality. This study aims to explore the effects of nitrogen (N) fertilizer types, fertilization rate, and application timing and gas collection method on NH3 volatilization during the maize season in Northern China. This study collected the publications on the NH3 volatilization from maize farming which were conducted in Northern China from 1980 to 2018, and undertook a systematic analysis. The study found that with the increase of N rate, the total and net NH3 volatilization at the basal and topdressing fertilization stages increased at exponential and power function, respectively. When the ratio of basal/topdressing N rate was 1/1, the total and net NH3 volatilization during the topdressing stage (58.4% of the whole season emission) was significantly higher than that in the basal fertilization stage (41.6%) (P<0.05). The priming effect first showed a negative effect and then gradually turned into a positive effect with the increase of N rate. Due to the positive priming effect, the net NH3 volatilization, without considering the priming effect, was overestimated under the conventional N application (>297 kg·hm-2). There is a significant difference between the NH3 volatilization measured by the venting method and the sponge absorption method, and the data from the venting method are more stable (P<0.01). Compared with conventional urea, slow-release urea may reduce NH3 volatilization by 20% to 50%. Control fertilizer N rate at the topdressing stage is more efficient in reducing the NH3 volatilization from maize production in Northern China, and the venting method is more suitable for the quantification of NH3 volatilization than the sponge absorption method under a high rate of fertilizer N.

Effects of controlled-release urea combined with fulvic acid on soil inorganic nitrogen, leaf senescence and yield of cotton

A split-plot field experiment was conducted in 2018–2019 to study the effects of nitrogen fertilizer types and fulvic acid (FA) rates on soil nitrogen and cotton growth. The nitrogen fertilizers included controlled-release urea (CRU) and urea, which were applied combined with three FA rates (90, 180 and 270 kg ha-1). The main plot was the nitrogen fertilizer type, and the subplot was the FA rate. The results showed that the lint yield of the FA180 treatment was 5.2–8.6% higher than the FA90 and FA270 treatments. Moreover, moderate FA application markedly improved the cotton leaf SPAD value (chlorophyll relative value), photosynthesis and chlorophyll fluorescence parameters compared with low and high FA rates. Replacing urea with CRU significantly increased the soil inorganic nitrogen and nitrogen use efficiency and also improved cotton fiber quality parameters. Meanwhile, the boll weight and seed yield of the CRU treatments were 1.5–8.4% and 3.3–19.1% higher, respectively, than the urea treatments. The interaction between nitrogen type and FA rate had a positive effect on cotton growth. Thus, the application of CRU combined with 180 kg ha-1 FA on cotton can not only improve the fiber quality and delay leaf senescence but also increase the yield and economic benefit.

In-Soil Application of NP Mineral Fertilizer as a Method of Improving Nitrogen Yielding Efficiency

This study presents the results of a four-year field experiment assessing the effectiveness of phosphorus application in maize cultivation according to the depth of two-component fertilizer (NP) placement in the soil layer, type of nitrogen fertilizer and date of application. Nitrogen utilization from mineral fertilizer was low—on average, 37.1% during the four years of research. The nitrogen metabolism index, measuring the agricultural and physiological efficiency of nitrogen use, confirmed the significant impact of NP fertilizer placement at 10 and 5 cm as optimal in maize fertilization. The use of nitrogen in maize cultivation before sowing, compared to the application of this component at the phase of 5-6 leaves BBCH 15/16 stage (stage of leaf development with five–six leaves unfolded), significantly increased the agricultural and physiological effectiveness of nitrogen applied in mineral fertilizer. Ammonium nitrate application before sowing the maize, compared to top dressing at the BBCH 15/16 stage, significantly increased nitrogen uptake and utilization from mineral fertilizer. Date of urea fertilizer application to the soil did not have a significant impact on these indicators in maize cultivation.

Regularities of sowing alfalfa productivity formation while using different types of nitrogen fertilizers in cultivation technology

The provision of alfalfa with the nutrients throughout the whole growing period is an important factor in influencing the yield. We researched the content of mineral nitrogen in the typical black soil and the productivity of green mass of sowing alfalfa. As a result of research, we have found that the use of CAM in comparison with ammonium nitre in the norm of 90 kg/ha increased the total nitrogen content in the green mass of alfalfa by 0.17%. The mineral compounds of nitrogen in the podzolized black soil were 36%-87% higher compared with the variant without fertilizers. Increasing the rate of phosphorus from 60 to 90 kg/ha increased the content of total phosphorus in sowing alfalfa by 0.09%-0.11% and potassium by 0.19%-0.23% respectively. When using the CAM rate N180 on the P60K60 background the highest yield of green alfalfa (43.5 t/ha) was obtained, the difference comparing to N110P90K120 did not exceed 5%. Correlative and regressive modeling allowed to establish that the content of mineral nitrogen is minimal (15 mg/ha) in the phase of restoration of alfalfa vegetation in the control variant and further was noted its rapid increase to 26-28 mg/kg on the background of nitrogen fertilizer application in doses N150-N180. In the flowering phase, a significant (19.4%-39.8%) decrease of calculated indices of the content of nitrogen mineral compounds was noted, but there appeared a steady dynamics of growth of these indices in the variants with high doses of nitrogen fertilizers. The optimal doses of fertilizer application have been determined at the level from 120 to 145 kg per 1 ha which provides yields of green mass at the level of 45-47 t/ha. The variability of productive features affirms the maximum impact on alfalfa productivity at mineral nutrition background-68.5%, the weather conditions account for 21.5%, the interaction of these factors takes 5.1%, and the influence of unaccounted factors is at the level of 4.9%.

The Role of Agrotechnical Factors in Shaping the Protein Yield of Maize (Zea mays L.)

The subject of the work was the evaluation of maize protein yield conditioned by various agrotechnical factors. The test results are derived from two different field experiments covering a total of seven years of observation. Protein yield was significantly dependent on changing weather conditions in the growing seasons. Protein yield was significantly lower in the dry and hot years. The sum of precipitation for the month of May was positively correlated with maize protein yield. However, there was no correlation between the average air temperature and the amount of protein yield. The sum of atmospheric precipitation for the entire growing season (IV–X) shaped maize protein yield in over 96%. A non-linear relationship of the 2nd degree was determined between these traits. Sowing maize into the soil cultivated traditionally (autumn tillage), “stay-green” type cultivars and row fertilization positively influenced maize protein yield. Initial fertilization (regardless of depth) with two-component NP fertilizer, in relation to broadcast fertilization, significantly increased maize protein yield from 11.4% to 18%, respectively. The type of nitrogen fertilizer did not differentiate the value of this trait. Pre-sowing nitrogen application was more effective compared to the top dressing, and significantly increased protein yield. Row fertilization with two-component NP fertilizer clearly affected the content protein in grain. The interdependence of genetic and agronomic progress is an important factor shaping the potential of maize protein yield and cannot be attributed to either breeding (cultivar) or agronomy.