Urea-ammonium Nitrate Solution Research Articles

Efficacy of fertilizer nitrogen source, stabilizer, and application timing for corn nitrogen nutrition

AbstractEnhancing fertilizer nitrogen use efficiency (NUE) in corn (Zea mays L.) production is critical for closing yield gaps, increasing producer profitability, and promoting environmental stewardship. In 2014 and 2015, a field experiment was conducted to determine the potential for fertilizer N stabilizer products to improve NUE of granular urea and urea ammonium nitrate (UAN) solution applied to strip‐till corn. A urease inhibitor (UI) or nitrification inhibitor (NI) or both were added at labeled rates to urea or UAN solution for a target rate of 180 kg N ha−1. At V3, a single application of broadcast granular urea and subsurface banded UAN solution with and without fertilizer N stabilizers was made. A split application (50% at V3; 50% at V6) of subsurface banded UAN solution served as a control representing a standard grower practice. Fertilizer N stabilizers improved components of NUE, such as grain N recovery efficiency (GNRE) and partial factor productivity (PFP). A single full rate UAN application did not differ in terms of grain yield each year but did result in less PFP and GNRE in 2015 as compared to the grower standard practice. A timely one‐time full season N rate subsurface banded application of UAN treated with UI and NI to improve NUE could be a viable substitute for the practice of multiple fertilizations. Untreated broadcast urea was inferior to UAN as a N source for corn, but when treated with both a UI and NI, NUE was improved.

Applying urea ammonium nitrate solution saves nitrogen resources by changing soil microbial composition under micro sprinkling fertigation: an effective nitrogen management practice

ContextHow to improve nitrogen (N) efficiency and reduce environmental pollution caused by N loss has attracted much attention. However, limited research has lacked a comprehensive exploration of the effects of applying UAN under the micro sprinkling fertigation on reactive N (Nr), fertilizer efficiency and net benefits including environmental costs, plus associated responses of the microbial metagenome. ObjectiveThe aim of this study was to assess the impact of N management practices on maize yield, Nr losses, and soil microbial community composition and function. MethodsUrea and urea ammonium nitrate solution (UAN) were used as N sources, and three N application rates (210, 168 and 0 kg N ha−1) and two fertilization methods (micro sprinkling fertigation and traditional fertilization) were set as the three key components. ResultsThe results showed that micro sprinkling fertigation treatments reduced Nr losses, increased yield and N efficiency. Compared with urea, the total NH3 volatilization and N2O emissions of UAN under micro sprinkling fertigation were decreased by 14.8% and 30.6%, respectively. Furthermore, the N reduction (FU1) treatment promoted plant N uptake, was saved 20% of N by affecting soil NH4+- N and NO3--N content, compared to that of urea, and it regulated the microbial abundance of N cycle function related to denitrification and N respiration, reduced global warming potential and greenhouse gas emission intensity. ConclusionsN application method, N source and N rate affected the diversity and composition of soil bacterial community, and altered Nr emissions by changing the abundance of functional microorganisms related to N cycle. Overall, improved N management practice was more conducive to increasing maize yield and net income, saving N resources, and reducing the risk of environmental damage. SignificanceOur results contribute to a comprehensive understanding of the impact of N management on summer maize production, providing an effective N management practice that is conducive to “green agricultural development”.

Effect of fertilisation with P, Mg or S enriched urea-ammonium nitrate solution on the management of macronutrients in common maize

The purpose of this study has been to determine the effect of fertilisation with urea-ammonium nitrate (UAN) solution enriched with P, Mg or S on the content of macronutrients in the grain and straw of maize. The following fertilisers were tested in the field experiment: ammonium nitrate, urea, UAN – 32% N; RSM+S – 26% N + 3% S; RSM+P(Medium) – 26% N and 4.80% P; RSM+P(Starter) – 21% N and 7.86% P; UAN + Mg – 20% N + 4% Mg. In each year of the experiment, significant differentiation in the contents of P, K, Ca, Mg and S in maize grain and straw was observed, depending on the applied nitrogen fertilisation. However, considering the average values from each treatment achieved over the three years, it was demonstrated that the fertilisation significantly changed only the content of P and S in grain and K and Ca in straw of maize. The removal of nutrients was the highest in the second year of the research and amounted in kg∙ha –1: P – about 100, K – about 350, Ca – about 80, Mg – about 35 and S – about 31, which in turn were differentiated over the years of the experiment in the three years. The removal of P, K, Mg and S also significantly depended on fertilisation. Significant differences, however, most often concerned the control treatment relative to the fertilised ones. The contribution of grain to the accumulation of nutrients also varied significantly in the three years of the experiment. Significantly the lowest share of grain in terms of P and S accumulation was noted in maize grown without N fertilisation.

Urea ammonium nitrate solution combined with urease and nitrification inhibitors jointly mitigate NH3 and N2O emissions and improves nitrogen efficiency of summer maize under fertigation

Urea ammonium nitrate solution combined with urease and nitrification inhibitors jointly mitigate NH3 and N2O emissions and improves nitrogen efficiency of summer maize under fertigation

Trace Element Content in Soils with Nitrogen Fertilisation and Humic Acids Addition

Application of mineral fertilisers can entail an increase in trace element content in the soil. In consequence, their elevated uptake by plants and transfer to further trophic chain links may occur. The aim of the research reported here was to determine the usefulness of the tested organic materials, such as humic acids, for reduction of the content of trace elements in two soils fertilised with excessive doses of nitrogen fertilisers. Soil type had a considerable effect on soil trace element content. The content of most trace elements (cadmium, lead, chromium, cobalt, nickel, manganese, and iron) was higher in loamy sand than in sand. Among the tested fertilisers, a higher content of most soil trace elements was found after the application of ammonium nitrate. Urea fertilisation led to a decrease in the content of cadmium, chromium, copper, and zinc in both soils; cobalt, manganese, and nickel in sand; and an increase in concentration of cobalt and manganese in loamy sand, relative to the subjects fertilised with ammonium nitrate. Urea ammonium nitrate solution (UAN) decreased the content of chromium, cadmium, copper, nickel, and zinc in both soils; lead in the sand; and cobalt in the loamy sand, while raising the content of lead in the loamy sand, relative to the subjects fertilised with ammonium nitrate. The impact of urea and UAN on the remaining trace element content in the soils was comparable to that effected by ammonium nitrate. The effect of humic acids on trace element content in the soil tended to be beneficial, as they reduced the soil concentrations of these elements compared to the control subject (without their application). However, it should be emphasised that their effect depended on nitrogen fertiliser form and soil type. Humic acids can effectively reduce the uptake of trace elements by some plant species.

Effect of Natural Liquid Hydroabsorbents on Ammonia Emission from Liquid Nitrogen Fertilizers and Plant Growth of Maize (Zea Mays L.) under Drought Conditions.

The use of mineral nitrogen (N) fertilizers is associated with significant nitrogen loss through the volatilization. Ammonia (NH3) emissions are common from fertilizers with amide (NH2) and ammonium (NH4) nitrogen forms applied to the soil surface without incorporation. The objective of the laboratory and greenhouse pot experiments was to verify the hypothesis that liquid mineral fertilizers and fertilizer solutions containing N-NH2 and N-NH4 applied to the soil surface in combination with natural hydroabsorbents (NHAs) will reduce the volatilization of nitrogen. The effect of NHAs addition to urea ammonium nitrate (UAN) fertilizer and urea, ammonium nitrate (AN) and ammonium sulphate (AS) solutions was evaluated in a laboratory experiment. The effect of the two types of NHAs (acidic and neutral) was compared with the control (UAN) and its mixture with the commercially used urease inhibitor N-(n-butyl) thiophosphoric triamide (NBPT). The proportion of volatilized NH3 of the total N from the examined fertilizers applied to the soil surface was determined by the titration method. Subsequently, the effect of fertilization with UAN and its mixture with NHAs and NBPT on the growth of maize under the drought conditions was verified in a greenhouse pot experiment. While the addition of NBPT resulted in a reduction of NH3 emission for the fertilizers containing NH2 (UAN, urea solution), a decrease in volatilization after the addition of both acidic and neutral NHA was observed especially for UAN. A reduction in ammonia emission was also observed for AS after the addition of acidic NHA. The addition of both NHAs and NBPT to UAN increased the utilization of nitrogen from the applied fertilizer, which was reflected by an increase in chlorophyll content and increased CO2 assimilation by maize plants grown under the drought stress. UAN fertilizer combined with acidic NHA and NBPT significantly increased aboveground biomass production and root system capacity of maize. Significant increases in UAN nitrogen recovery were observed for all examined additives (UI and both types of NHAs). In addition to the known effects of hydroabsorbents, especially their influence on soil physical and biological properties and soil water retention, the effect of NHAs application in combination with UAN and AS solutions on the reduction of gaseous N loss, maize plant growth and fertilizer nitrogen recovery was found.

Leaf Scorching following Foliar Fertilization of Wheat with Urea or Urea–Ammonium Nitrate Is Caused by Ammonium Toxicity

Foliar fertilization is a potential tool to increase the use-efficiency of nitrogen (N) fertilizers. However, whilst leaf scorching has frequently been reported, the underlying physiological processes are not clear. In the present work, we investigate the intensity of leaf scorching as affected by the balance between ammonium assimilation and accumulation. Leaves were sprayed with urea–ammonium nitrate (UAN) solution without surfactant or applied liquid droplets of urea in different N concentrations with surfactant. UAN solutions without surfactant containing >10% N caused leaf scorching already after 24 h and the severity increased with the N concentration. The same pattern was observed 3 days after the application of urea solutions containing >4% N together with surfactant. The scorching was accompanied by a massive increase in foliar and apoplastic ammonium (NH4+) concentration. Moreover, the activity of glutamine synthetase (GS), most pronouncedly that of the chloroplastic isoform (GS2), decreased a few hours after the application of high N-concentrations. Along with this, the concentration of glutamate—the substrate for GS—decreased. We conclude that leaf scorching is promoted by NH4+ accumulation due to a limitation in N assimilation capacity.

Optimising the root traits of summer maize to improve nutrient uptake and utilisation through rational application of urea ammonium nitrate solution

The production of summer maize is greatly affected by nitrogen (N) sources through regulating root growth and distribution. Four N treatments in the field experiment were designed as UAN (urea ammonium nitrate solution was applied under traditional side-dressing method), urea (urea was applied under traditional side-dressing method), UWFI (UAN was applied underwater and fertiliser integration technology) and CK (no N applied). The results showed that the root length density, surface area density and volume of DH605 (mid-late hybrid) and DH518 (mid-early hybrid) under UWFI were higher than other treatments, especially in shallow layers. The root absorption area of each soil layer under N application treatments varied with the growth stage. The grain yield and the accumulations of N, P and K in the shoots showed the trend of UWFI > UAN > urea > CK. Compared with UAN and urea, the nitrogen agronomic efficiency of UWFI treatment increased by 40.5~78.6%, and the nitrogen partial factor productivity increased by 4.75~7.61%. Consequently, rational application of UAN would improve root traits, nutrient uptake and utilisation, and yield of summer maize.

Increasing grain yield, nitrogen use efficiency of summer maize and reducing greenhouse gas emissions by applying urea ammonium nitrate solution

AbstractThe contradiction between the high grain yield of summer maize (Zea mays L.) and greenhouse gas (GHG) emissions in the field can be resolved by selecting effective nitrogen (N) sources and fertilization methods. In this study, two fertilization methods were used: (a) urea ammonium nitrate solution (UAN) and urea (210 kg ha–1 nitrogen applied) were applied by farmers' traditional fertilization method; and (b) fertigation of four UAN application rates: CK (no N applied), AF1 (126 kg N ha–1), AF2 (168 kg N ha–1), AF3 (210 kg N ha–1). The results showed that both hybrids (DH518 and DH605) applied UAN under the traditional fertilization method increased grain yield by 2.4 and 1.8% and enhanced nitrogen use efficiency (NUE) by 25.1 and 9.9%, respectively, compared with urea. While under fertigation treatment, the grain yield increased by 7.6 and 6.6%, and the NUE increased by 23.2 and 12.4%. Grain yield increased with the increase of UAN application, and the NUE showed a trend of rising first and then falling under fertigation treatment. Both the cumulative N2O emissions and N2O emission factor showed an increasing trend as well. An application rate of UAN at 168 kg N ha–1 (AF2) resulted in a NUE that was 49% higher than urea. Compared with urea, the global warming potential (GWP) and greenhouse gas intensity (GHGI) of AF2 were reduced by 29.5% and 31.2%, respectively. These indicated that optimizing the application rate of UAN through fertigation would achieve better summer maize yield and environmental benefits.

Ammonia volatilization from manure mixed with biochar

Ammonia (NH3) volatilization from NH3-based fertilizer and animal manure reduces their nitrogen (N) fertilizer value and is a source of environmental pollution. Mixing manure with biochar may lower NH3 volatilization from manure by adding H+, adsorbing mineral N, or increasing N immobilization in microbial biomass. The objective of this study was to determine whether wood-based biochar could lower NH3 volatilization from vented pails containing manure (liquid swine, dairy slurry, and solid poultry manure) or a urea ammonium nitrate solution (UAN). Two types of wood-based biochar (BlueLeaf and Dynamotive) were mixed with three types of manure and UAN fertilizer solution at 0, 2.5, 5, 10, and 25% biochar by volume in vented pails. After 21 d storage in an outdoor shaded area, the greatest NH3 volatilization was from poultry manure, which had pH 9.4 on average and low water content regardless of the biochar source and application rate. There was less NH3 volatilization from UAN fertilizer solution when mixed with 25% (v/v) of Dynamotive biochar compared with NH3 volatilization from UAN fertilizer solution mixed with 0%–10% (%) of Dynamotive biochar, probably because pH decreased from 7.0 to 6.4 after 21 d contact. Mixing wood-based biochar with manure had no impact on NH3 volatilization, suggesting that these biochar sources did not appreciably change the pH and N dynamics in stored manure after 21 d.

Content of micronutrients in grain and straw of common maize fertilized with urea-ammonium nitrate solution with added P, Mg or S

Content of micronutrients in grain and straw of common maize fertilized with urea-ammonium nitrate solution with added P, Mg or S

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.

VNT4, a Derived Formulation of Glutacetine® Biostimulant, Improved Yield and N-Related Traits of Bread Wheat When Mixed with Urea-Ammonium-Nitrate Solution

Optimizing nitrogen use efficiency (NUE) could mitigate the adverse effects of nitrogen (N) fertilizers by limiting their environmental risks and raising agronomic performance. We studied the effects of VNT4, a derived formulation of Glutacetine® biostimulant, mixed with urea-ammonium-nitrate solution (UAN) on the growth, N-related traits and agronomic performance of winter wheat (Triticum aestivum L.). The experiment was performed under six contrasting field conditions over two years in Normandy (France), including a site where 15N labelling was undertaken. Taking into account all the sites, we report that VNT4 significantly improved grain yield (+359 kg ha−1), total grain N and NUE. VNT4 application improved growth during tillering and stem elongation (+10.7%), and N and 15N uptake between tillering and maturity (+7.3% N and +16.9% 15N) leading to a higher N accumulation at maturity (+9.3% N). This N mainly originated from fertilizer (+19.4% 15N) and was assimilated after the flag leaf stage in particular (+47.6% 15N). These effects could be related to maintenance of physiological functions of flag leaves as suggested by the enhancement of their nutrient status (especially S, Zn and Mo). The adoption of VNT4 as a UAN additive is an efficient agronomic practice to enhance wheat productivity under an oceanic temperate climate.

Nitrogen fertilization strategies for improved Mediterranean rainfed wheat and barley performance and water and nitrogen use efficiency

Adequate fertilization strategies are paramount to fulfill increasing demands for food, feed and fiber while reducing environmental impacts. However, their optimization under Mediterranean no-till systems has received little attention. The objective of this work was to assess winter cereal yield and water and N use efficiencies in a rainfed semiarid Mediterranean climate under (i) a range of pre-plant fertilizers [control without N fertilizer (0 N), and the following at 75 kg N ha−1: mineral N (MIN), swine slurry (SS), poultry manure (PM), and compost (COM)], (ii) fertilizer incorporation: no-tillage without incorporating (NT) or incorporation with a vibrocultivator (INC) and (iii) application of urea-ammonium nitrate solution (UAN) as top-dress as a control without UAN (UAN-) or 50 kg N ha−1 (UAN+). The experiment covered six cropping seasons (2012–2019).Pre-plant applications had similar responses in crop yield, biomass, N uptake, grain N, water-use efficiency for biomass (WUEb), and water-use efficiency for yield (WUEy) but were greater than 0 N. The lack of differences between pre-plant fertilizers would be explained by the high amount of residual N and the mineralized N during the crop cycle. Top-dress UAN increased WUEy and crop yield in all the cropping seasons by an average of 587 kg grain ha−1, which represented 18 % of the total annual production. Averaged across variables and the growing seasons, INC reduced soil water content and WUEb by 10 % (from 24.3 to 21.8 kg ha−1 mm−1). Also, INC reduced grain yield by 9% (from 3799 to 3450 kg ha−1) by reducing the number of spikes m-2 produced, pointing out that INC resulted in water deficit during the early reproductive period of the crop. While INC is often consider a best management practice to reduce NH3 volatilization losses from broadcast fertilizer applications, the results demonstrate that in rainfed Mediterranean agroecosystems water is more limiting than the N that could be potentially lost by volatilization.

Influence of Mineral Fertilizers and Other Agrotechnical Cultivation Methods on Yield and Grain Protein Content of Winter Wheat

It is established that in the conditions of the northern steppe of Ukraine to obtain comparable results in the amount of protein in winter wheat grain it is necessary after such predecessors as stubble and sunflower, to apply a higher dose of nitrogen in complete pre-sowing fertilizer, as well as in spring fertilization, than when growing on black fallow. In the case of fertilization at the end of plants tillering with nitrogen with a local dose of N₆₀, the yield after spring barley, depending on the variety of winter wheat increased by 0.66-0.82, and for black fallow - by 0.58-0.64 t/ha. Among winter wheat varieties Kokhanka, Misia Odeska and Pylypivka, the highest yields and grain quality were observed in Pylypivka variety. It was found that among nitrogen fertilizers (ammonium nitrate, Urea Ammonium Nitrate solution - UAN-32, and ammonium sulfate) the best results in protein formation in grain in most cases provided the introduction of UAN-32 and ammonium sulfate. Strong in grain quality, winter wheat varieties Niva Odeska and Uzhynok, both after sunflower and black fallow, outperformed Kokhanka variety in terms of protein content. It is established that the highest grain productivity of different varieties of winter wheat, both when grown after spring barley and black fallow, was observed at the optimal sowing date (September 22); the variety of durum wheat Burshtyn formed a higher protein content in the grain (13.5-14.6%) than varieties of soft wheat - Golubka Odeska (12.0-12.6%) and Lastivka Odeska 13.2-13.6%). It was found that in the research years the amount of protein in the grain of winter wheat depended more on crop fertilizer than on the sowing date.

Nutrient recovery from anaerobic digestion of food waste: impacts of digestate on plant growth and rhizosphere bacterial community composition and potential function in ryegrass

Global food wastage equates to about 1.3 billion tons per year, which causes serious environmental impacts. The objective of this study was to evaluate the influences of addition of digestate from food waste in comparison to a synthetic liquid urea ammonium nitrate solution on plant growth, rhizosphere bacterial community composition and diversity, and hyphal abundance of arbuscular mycorrhizal (AM) fungi. Plant and soil samples were collected at 25, 50, and 75 days after seedling emergence. Annual ryegrass growth was significantly increased by both liquid urea ammonium nitrate and digestate, and digestate was just as effective as liquid urea ammonium nitrate. Additionally, digestate (50 kg N ha−1) significantly increased AM fungal hyphae density. Liquid urea ammonium nitrate (50 kg N ha−1) significantly decreased AM fungal hyphae density compared with liquid urea ammonium nitrate (25 kg N ha−1) at DAE 75. Digestate and liquid urea ammonium nitrate applications significantly shifted the bacterial community composition and OTU richness and changed the abundance of microbial C and N-cycling genes, while application rates had no significant effect. Structural equation modeling showed that digestate and UAN addition both directly and indirectly affected bacterial, C and N cycling genes community composition; the indirect effects were related to increased soil NO3− content and reduced pH. This study showed that the use of digestate as a soil amendment can be environmentally effective and can provide a sustainable supply of nutrients that increases soil organic C. Moreover, the use of digestate can readily be incorporated into agricultural practices with potentially less impact on soil microflora diversity and function than conventional fertilizers.

Urea Ammonium Nitrate Solution Treated with Inhibitor Technology: Effects on Ammonia Emission Reduction, Wheat Yield, and Inorganic N in Soil

Urea is the most used fertilizer nitrogen (N), and is often applied as urea ammonium nitrate (UAN), which may be an ammonia (NH3) emission source after application. This study examined whether the addition of urease inhibitors reduced NH3 emission, and, in combination with nitrification inhibitors, enhanced fertilizer N crop uptake. In three experiments, NH3 emission was measured from plots (100 m2) to which UAN was added with and without inhibitors. In March and May, the plots were covered with Triticum aestivum L., Sheriff (var), and in July, the soil was bare. The inhibitor mixed with urea was N-(n-butyl) thiophosphoric triamide (NBPT) and a mixture of NBPT and the new nitrification inhibitor DMPSA (3,4-Dimethylpyrazole succinic acid). Ammonia emissions were negligible from all plots after the first application of UAN due to the wet and cold weather while an average of 7% of applied UAN was emitted after application of UAN in April, where no significant effect of additives was observed. The harvest yield was low due to drought from May till August. Yield was highest when UAN was mixed with NBPT and lowest for untreated UAN. The highest emission from the bare plots was obtained from untreated UAN (17% of N), in contrast to 11% of N from the plots with added UAN + NBPT (not significant) and 7% from the plots with added UAN + NBPT + DMPSA (significantly different). Under the conditions of the current study, urease inhibitors reduce NH3 emissions in periods where the risk of emission is high, and the combination of urease and nitrification inhibitors increased yields.

Long‐term in‐season grain sorghum and soybean response to tillage and nitrogen management

AbstractInformation on tillage and N management is limited regarding in‐season N uptake by grain sorghum [Sorghum bicolor (L.) Moench] and growth of soybean [Glycine max (L.) Merr.] on claypan soils in the eastern Great Plains. The objective of this study was to determine the 20‐yr effects of tillage (conventional, reduced, and no‐till) and N fertilization (no‐N control; knifed anhydrous NH3; broadcast urea–ammonium nitrate solution, UAN; and broadcast dry urea) on grain sorghum N uptake and soybean biomass and their relationship to long‐term yields of those crops grown on a claypan soil. Nitrogen uptake at the boot stage during the first 10‐yr period was more than 20% greater with either conventional or reduced tillage compared with no‐till, and often greater with anhydrous NH3 and urea N sources than with UAN solution or the no‐N control. During the second 10‐yr period, N uptake was generally greater with conventional and reduced tillage than with no‐till at the 9‐leaf stage, but this response did not persist to the boot stage. Anhydrous NH3 often resulted in greater N uptake at both the 9‐leaf and boot stages compared with the other N sources. The relative yield increases with N uptake at the boot stage appeared due to increasing kernels head−1 but diminished as uptake exceeded 70−80 kg N ha−1. Although dry matter measured at the R2 growth stage of soybean rotationally grown in even‐numbered years was about 10% greater with tilled options than with no‐till, biomass was not related to yield increases.

Development of a liquid-jet nozzle for fertilizer injection in paddy fields using CFD

The current broadcasting method for chemical fertilizer applications for rice production causes significant nitrogen losses through volatilization. To minimize this problem, a liquid-jet nozzle was developed for injection of liquid fertilizer in paddy fields. With computational fluid dynamics (CFD), the liquid-jet nozzle was modelled to examine the mass flow rates and velocities as affected by the critical design parameters of the nozzle: fertilizer inlet diameter (df) and nozzle orifice diameter (do). The model was validated with tests, and the performance of the liquid-jet nozzle was evaluated through injecting Urea Ammonium Nitrate solution into a clay loam soil. Simulation results showed that flow velocities decreased and mass flow rates increased at larger do values in a non-linear fashion. Effects of df were less pronounced and depended on the values of do. The model results agreed well with the test results with relative errors between 0.4 and 13.3%. Considering the requirements of nitrogen application rates for rice (60–180 kg ha−1) and soil cutting depths (20–50 mm), the optimal design parameters for the liquid-jet nozzle were the combinations of (df, do): (1.0, 1.0 mm) for producing the highest nitrogen application rate, and (0.6, 0.8 mm) for having the highest ability in cutting soil. The liquid-jet nozzle, a non-traditional injection method, has high potential to become a cost-effective and low soil-disturbance practice for rice production.

The economic efficiency of the fertilizers application under agricultural crops for different soil tillage

In the Ukrainian economic conditions there is a competition between producers of the crops products and it caused their competitiveness in national and international markets. This causes increasing of the farm efficiency. One of the ways for increasing of the farm efficiency is minimization of the soil tillage and rational use of fertilizers. So, the rational fertilizers application for different soil tillage was researched. There were ploughing and mini-till and no-till and split formation. The effect of the ammonium nitrate application and UAN solution on background of the phosphate-potassium fertilizers were researched for these types of soil tillage. These factors were researched for next crops: corn, soybean and spring wheat. For corn the rate of mineral fertilizers was N 140 P 100 K 100 , for soybean it was N 60 P 60 K 60 , for spring wheat it was N 100 P 80 K 80 . Results indicate that the optimal soil tillage for all crops was split formation. And better nitrogen fertilizers were urea-ammonium nitrate solution for two crops (soybean, spring wheat) because in these variants was maximal profitability in these crop production system. It was 95.0 % for soybean and 58.1 % for spring wheat. For corn the best fertilizers were ammonium nitrate where was maximal profitability (54.7 %).