Urea Application Research Articles

Enhancing soil quality for sustainable agricultural practices in Subak rice fields

Understanding the soil quality of Subak rice fields in Bali is crucial for maintaining agricultural sustainability. This study aimed to explore aspects of soil quality, identify limiting factors, and offer guidance on sustainable land management. Utilizing survey methods, laboratory analysis, and soil quality determination, soil samples were selectively collected from each land unit (LU). LU selection was based on overlays of Subak zonation, soil type, slopes, rainfall, and elevation using Geographic Information System (GIS) techniques. Key soil quality indicators were assessed, including bulk density, texture, porosity, moisture content, pH, organic carbon, cation exchange capacity, base saturation, and nutrients (N, P, K). Overall, soil quality in the study area is classified as good in all LUs, but with significant variations in Soil Quality Index (SQI) values, suggesting the need for tailored management recommendations. Limiting factors include soil texture, organic carbon content, total nitrogen, available phosphorus, and biomass C. Recommended soil management practices include single plow tillage and the application of manure, urea, and SP-36 fertilizer on paddy fields. This approach aims to enhance land productivity sustainably while upholding environmental conservation and the principles of Subak, which have historically maintained a balanced and sustainable agricultural ecosystem.

Combined use of NBPT and micronutrients in granulated or coated urea: A new approach to reduce ammonia volatilization losses from soil

AbstractN‐(n‐Butyl) thiophosphoric triamide (NBPT) is the most widely adopted urease inhibitor, used to reduce ammonia (NH3) volatilization from urea. Micronutrients such as boron (B), zinc (Zn), nickel (Ni) and molybdenum (Mo) are also reported to inhibit urease, serving simultaneously as plant nutrients. However, there is little information on the potential synergistic or antagonistic effects of NBPT and micronutrients on urea protection. The aim of this study was to evaluate NH3 volatilization losses, soil pH and soil mineral nitrogen content (‐N and ‐N) after application of urea coated or granulated with the micronutrients B, Zn, Ni or Mo, individually. Thereafter, the fertilizers were applied combined and not associated with NBPT. Ammonia volatilization was measured in a closed static chamber under controlled conditions. Urea granulated with B and Zn reduced NH3‐N volatilization circa 30% compared with untreated urea, while Mo and Ni had no effect. NBPT stabilizer had the greatest effect on NH3‐N volatilization (44%–59% reduction), but was less effective (only 20%–34% reduction) when urea was coated with B, Zn or Mo. On the other hand, when B and Zn were incorporated via granulation, the efficiency of NBPT was not reduced, likely because of the physical separation. These findings demonstrate that granulating urea with B or Zn combined with an NBPT‐coating can be a valuable strategy to reduce NH3 volatilization losses while also supplying micronutrients and hence potentially increase yields in agricultural production systems.

Interactions between arsenic and nitrogen regulate nitrogen availability and arsenic mobility in flooded paddy soils

In paddy soils, arsenic (As) stress influences nitrogen (N) transformation while application of N fertilizers during rice cropping affects As transformation. However, specific interactive effects between As and N in flooded paddy soils on As mobility and N availability were unclear. Here, we examined N and As dynamics in flooded paddy soils treated with four As levels (0, 30, 80 and 150 mg kg−1) and three urea additions (0, 4 and 8 mmol N kg−1). Arsenic contamination inhibited diazotrophs (nifH) and fungi but promoted AOA and denitrification genes (narG, nirK, nirS), decreasing dissolved organic N, NH4+-N and NO3–-N. Besides, urea application stimulated As- and Fe-reducing bacteria (arrA and Geo) coupled with anammox. On Day 28, the addition of 8 mmol N kg–1 increased total As concentrations in solutions of soils treated with 30 and 80 mg As kg−1 by 2.4 and 1.8 times compared with the nil-N control. In contrast, at 150 mg As kg−1, it decreased the total As concentration in soil solution by 63 % through facilitating As(III) oxidation coupled with NO3–-N reduction. These results indicate that As contamination decreases N availability, but urea application affects As mobility, depending on As contamination level.

Effects of inhibitors and slit incorporation on NH3 and N2O emission processes after urea application

The use of urea fertilizers in agriculture is associated with many negative environmental impacts and is a source of ammonia (NH3) and nitrous oxide (N2O) emissions. Such losses from urea fertilizer can be avoided by different mitigation techniques. Three different mitigation principles, urease inhibitor (N-(2-Nitrophenyl) phosphoric triamide, 2-NPT) (UI) alone and urease inhibitor in combination with nitrification inhibitors (N-[3(5)-methyl-1 H-pyrazol-1-yl) methyl] acetamide, MPA) (NI) and closed slit incorporation of urea fertilizer into the soil, were compared on a sandy loam soil at a soil water level of 70 % water-holding capacity. An in vitro microcosm approach with open dynamic incubation chambers was used to monitor NH3 emissions over two weeks with NH3 sampling by washing bottles. N2O emissions were studied over ten weeks in slow throughflow mesocosms with continuous gas chromatographic (GC) measurements. To get insights into N2O production and consumption processes, gas samples were taken after six weeks and N2O isotopocules were analyzed by isotope ratio mass spectrometry (IRMS). Slit injection showed the greatest effect on NH3 emission reduction by 79.6 % (40.6 % by UI, and 46.7 % by UINI) compared to surface applied urea. Minor pollution swapping to N2O was observed at the beginning of the trial due to incorporation but not in the cumulative emissions over the entire incubation time. The reduction effect of UINI on N2O emissions decreased over time with no cumulative emission reduction at the end of experimentation. N2O isotopocules confirmed the high contribution of nitrification to N2O production. In contrast and bacterial denitrification, nitrifier denitrification and fungal denitrification were involved on a much lower level and N2O reduction to N2 was not pronounced. All NH3 mitigation measurements where effective to decrease NH3 emissions while their effects on N2O emission varied over time. Factors as crop N uptake and rainfall would further modify the overall effect on N2O emissions and need to be considered for final pollution swapping assessment. Further research on the impact of NI on non-target microbial communities is warranted to elucidate potential environmental consequences and long-term efficacy of inhibitor compounds.

Effect of Nano Urea on Growth, Yield and Nutrient uptake of Finger Millet (Eleusine coracana L.)

Aim: The foliar application of nano urea is aimed at reducing the soil application of conventional urea. Nano fertilizers enhance crop growth and yield while enhancing nutrient uptake and reducing costs. They provide precise nutrient management, match crop growth stages, and offer an increased surface area for metabolic reactions. This boosts photosynthesis, leading to higher dry matter production and crop yield. Foliar application of nano urea (liquid) at tillering and booting stages in finger millet fulfills the nitrogen requirement and reflects higher crop productivity. Higher productivity of crops in a sustainable manner could be achieved by applying an appropriate combination of conventional fertilizers and nano fertilizers. Study Design: The experiment was laid out in split design with three replications. Place and Duration of Study: A field experiment was conducted in deep black soils at Agricultural Research Station, Siruguppa, during kharif 2022. Methodology: There were sixteen treatment combinations, consisting of different doses of nitrogen (no nitrogen, 50% RDN, 75% RDN and 100% RDN) with different concentrations of nano urea and conventional urea sprayed at tillering and booting stages for HR-13 variety of finger millet. Results: Application of 100% RDN has recorded significantly higher plant height, tillers plant-1, total dry matter accumulation, grain yield and straw yield (129.82 cm, 10.10, 36.17 g plant-1, 36.87 q ha-1 and 71.72 q ha-1, respectively) in comparison to no nitrogen and 50% RDN. However, 75% RDN (123.04 cm, 9.61, 34.02 g plant-1, 34.84 q ha-1 and 68.01 q ha-1, respectively) found on par with 100% RDN. Among foliar nitrogen, spray of nano urea @ 4 ml L-1 recorded significantly higher plant height (121.59 cm), tillers plant-1 (9.37), total dry matter accumulation (33.16 g plant-1), grain yield (31.97 q ha-1) and straw yield (65.52 q ha-1) compared to 0.5% and 1% conventional urea. However, nano urea @ 2 ml L-1 was on par with 4 ml L-1 nano urea and 1% conventional urea. Similar trend was recorded with regard to nutrient uptake by finger millet. Conclusion: Foliar application of nano urea reduced the dosage of conventional urea by 25 per cent.

Field Evaluation of Urea Fertilizers Enhanced by Biological Inhibitors or Dual Coating

Relative to soluble N sources, enhanced-efficiency fertilizers (EEFs) support steady turfgrass growth and dense canopy quality while abating N loss as nitrate, ammonia, and/or N2O from turfgrass systems. Modern EEFs provide turfgrass managers greater operational effect and versatility in their nutrient management efforts and compel field characterization of their temporal response. Likewise, field confirmation of commercial EEF nutrient recovery helps stakeholders select the appropriate EEF for their specific application. Our research objective was to quantify the temporal response of Kentucky bluegrass growth/yield, canopy density and color, and fertilizer N recovery to a practical application of conventional urea or an enhanced-efficiency granular fertilizer. In May 2014 and June 2018, Kentucky bluegrass plots were fertilized by granules of conventional urea, N-(n-butyl) thiophosphoric triamide (NBPT)-, and dicyandiamide (DCD)-stabilized urea, or polymer-/sulfur-coated urea (PSCU) at a N rate of 43.9 kg ha−1 (0.9 lbs/1000 sq. ft.). The dependent variable response over the two growing seasons was highly affected by efficiency enhancement. Following the repeated 16.5-week evaluations, the mean percent of fertilizer N recovered from conventional urea, stabilized urea, and PSCU totaled 57.5, 68.4, and 89.1%, respectively. In the 23 to 51 days from treatment (DFT), recovery of PSCU-N significantly exceeded that from conventional or stabilized urea.

Sustainable urea treatment by environmental-friendly and highly hydrophilic vesicle-like iron phosphate-based carbon

Despite the versatile potential applications of urea, its unfavorable characteristics for conventional treatment methods hinder its utilization. Therefore, this study developed vesicle-like iron phosphate-based carbon (IP@C400) as a breakthrough urea removal and recovery material for a wide range of urea-containing sources. IP@C400 rapidly exhibited an exceptional capacity (2242 mg/g in 1 h) across a wide range of pH, even in synthetic hemodialysis wastewater with high urea concentrations and diverse co-existing components, compared with the 60 prominent adsorbents. The adsorption process followed dual Pseudo-kinetic, Langmuir-isotherm models with the involvement of primary robust physical (i.e., H-bonding and electrostatic interaction) and chemical mechanisms (i.e., hydrolysis). Remarkably, IP@C400 can maintain high urea removal (90 %) or recovery efficiency (95 %) even after 10 cycles with minimal leakages of Fe and P (far below WHO and EUWFD standards)—a significant improvement over disposable options. IP@C400 could also perform efficiently on batch and a new approach integrating with a naturally accessible material based on the fixed-bed column using low-range urea realistic samples, achieving 65.2 L water over 10 cycles with undetected urea, neutral pH, and well-aligned water safety standards with a minimal adsorbent dose (0.1 g.L−1) and economical cost ($0.05 L-1). Lastly, its environmentally friendly nature, which contains essential nutrients for plant growth, further enhances its recyclability after release. Thus, IP@C400 offers a solution to environmental sustainability and the urgent ultrapure water issue that industries are facing.

Agronomic responses and economic returns from wheat–canola rotation under Humalite and urea applications

AbstractHumalite is a humic acid‐rich biostimulant known for its ability to improve plant agronomic parameters and increase crop nitrogen use. Limited field research exists on Humalite effect, its application rate, and its interaction with urea, especially at reduced rates on grain agronomic parameters. Therefore, a field study was conducted from 2021 to 2023 at three Alberta sites—Battle River Research Group (BRRG), Gateway Research Organization (GRO), and St. Albert Research Station (St. Albert), in a split‐plot design with four replications, three urea levels (i.e., recommended, half‐recommend, and zero urea) combined with five Humalite rates (0, 56 (or 112), 224, 448, and 896 kg ha−1). In 2021, the highest wheat yields were observed at half urea rates plus 224 kg ha−1 at BRRG (35% yield increase), GRO (8.4% yield increase), and St. Albert (33.5% yield increase). In 2022, canola yields were unaffected by Humalite application rates. In 2023, wheat yields from half‐recommended and recommended urea rates plots outperformed zero urea plots across all sites, regardless of Humalite rates. The highest wheat grain protein content values were observed at 224–448 kg ha−1 of Humalite plus half‐recommended or recommended urea rate. Depending on the site, the highest net revenue resulted from half urea rates plus Humalite at application rates between 112 and 448 kg ha−1 in wheat, that is, optimal Humalite rate for increased profitability. Therefore, the incorporation of biostimulants such as Humalite can reduce urea use and contribute to the sustainability of wheat cropping systems.

The Combined Application of Urea and Fulvic Acid Regulates Apple Tree Carbon and Nitrogen Metabolism and Improves Anthocyanin Biosynthesis

Improving apple peel color has been an important objective in apple production. To better understand the effect and mechanism of the combined application of urea and FA (fulvic acid) regulation of anthocyanin biosynthesis, a field experiment was performed in 2022 and 2023, respectively, under five treatments of urea + FA (CK, urea only; FA50, urea + 50 kg ha−1 FA; FA100, urea + 100 kg ha−1 FA; FA150, urea + 150 kg ha−1 FA; FA200, urea + 200 kg ha−1 FA), using isotope (13C and 15N) marking to analyze the changes in carbon (C) and nitrogen (N) nutrient distribution as well as anthocyanin biosynthesis in fruits. We observed that, under FA application conditions, anthocyanin content in the peel was elevated in both years, with increases of 15.98~52.88% in 2022 and 15.93~52.94% in 2023. The best promotion effects were observed under FA150 treatment. Apart from the expression levels of anthocyanin biosynthesis-related genes and transcription factors in the apple peel, this positive effect on anthocyanin content induced by FA addition was also found to be associated with the optimization of C and N distribution in leaves and fruits. On the one hand, the application of FA not only enhanced leaf photosynthetic-related indexes (such as Pn, Gs, and Rubisco activity) and influenced (increased) S6PDH, SPS, and SS activities in leaves, but also elevated fruit sugar metabolism-related enzyme (SDH, SS-c, AI, and NI) activity and upregulated fruit stalk sugar transporter (MdSOT1, MdSOT3, MdSUT1 and MdSUT4) gene expression, which ultimately promoted the synthesis and the leaf to fruit transport of photosynthates, thus promoting 13C-photosynthate accumulation in fruits. On the other hand, FA application elevated leaves’ N metabolism-related enzyme (GS and GOGAT) activity and optimized 15N distribution in leaves and fruits. Moreover, we also observed that FA application altered the fate of N fertilizer in apple orchards, showed an elevation in apple tree 15NUE and soil 15N residuals and showed a decrease in soil 15N loss. In summary, the appropriate application of FA150 (urea + 150 kg ha−1) synergistically optimized C and N nutrient distribution, and promoted anthocyanin biosynthesis in apple trees.

Growth Parameters and Protein Content of Maize as Influenced by Sowing Methods and Different Levels of Nitrogen

The field experiment was carried out at Research Farm, Integral University, Lucknow, Uttar Pradesh, India during Kharif season, 2021. The experiment envisages to study the effect of Sowing methods and different Nitrogen levels on yield and attributes of maize crop. The experiment was laid down in the Split Plot Design and the treatments were replicated three times. The maximum plant height of 56.92 cm, 235.17 cm and 237.16 cm was observed in the ridge method of sowing at knee height stage, tasselling stage and at harvest stage, respectively. Among nitrogen levels, the maximum plant height of 57.61 cm, 235.29 cm and 238.38 cm was observed at knee height stage, tasselling stage and at harvest stage, respectively in the treatment (N5) 25% N through granular urea + 75% N through Nano-urea. Among nitrogen levels, the maximum DMA of 86.30, 425.36 and 1287.73 g sqm-1 day-1 was observed at knee height stage, tasselling stage and at harvest stage, respectively in the treatment (N5) 25% N through granular urea + 75% N through Nano-urea. At harvest stage number of leaves per plant were highest in the S1 (14.33) and N5 (16.13) treatment. Among nitrogen levels, the maximum leaf area index (LAI) of 1.55, 2.49 and 1.9 was observed at knee height stage, tasselling stage and at harvest stage, respectively in the treatment N5. Among sowing methods, highest protein content was found in the ridge method (10.14%) followed by flat method (9.81%) and broadcast method (9.42%) of sowing. The protein yielded maximum of 586.15 kg ha-1 in the N5 treatment. All parameters showed better in granular urea application rather than nano-urea, when used solely.

Participation of urea application stages on flour quality in bread wheat

Laboratory studies, which field trial was conducted in the 2020-2021 growing season at the Eastern Mediterranean Agricultural Research Institute, were conducted at Gümüşhane University. In this study, the findings showed that urea was used as the top fertilizer in different growth stages of the 'Yakamoz' bread wheat cultivar used as material, and the effects of urea application periods and flour type, on the quality traits, such as dry matter, ash, protein, acidity, fresh and dry gluten, gluten index, sedimentation, and falling number were investigated. For this purpose, in addition to the control application, tillering, stem elongation, milky and dough stages were chosen as urea application periods. Laboratory studies were carried out in randomized plots using the split-plot design with three replications. In the present study, all quality traits showed statistically significant differences for urea application periods; these values were ranged as follows: Dry matter: 90.20-90.77%, ash: 1.037-1.213%, protein: 14.01-15.15%, acidity: 0.037-0.056%, wet gluten: 41.49-43.67%, dry gluten: 14.75%-15.46, gluten index: 69.28-80.38%, sedimentation: 20.0-21.0 mL, late sedimentation: 23.5-29.8 mL and falling number: 753.8-881.7 s. In addition, other quality parameters except dry matter, protein and sedimentation changed statistically for flour type. Accordingly, whole wheat flour for ash (1.443%), acidity (0.051%) and gluten index (82.53%); white flour showed high values for wet (44.90%) and dry (15.96%) gluten, late sedimentation (35.60 mL) and falling number (836.4 s). As a result, while applying urea as a top fertilizer, it is recommended to choose the stem elongation stage for high gluten index, delayed sedimentation and protein, and the dough maturity stage for high dry matter. It would be appropriate to represent more genotypes and different nitrogen sources in further studies to be more inclusive.

Effect of Nano Urea on Leaf Nutrients and Some Quality Parameters of Tea (Camellia sinensis (L) O. Kuntze)

Some important parameters of tea on mature plants of TV 23 clone were studied after application of Nano-urea as foliar spray at Experimental Garden for Plantation Crops, Assam Agricultural University, Jorhat during the period 2021-2022. The usage of "Nano Urea" (Liquid), a novel product created and patented by Indian Farmers Fertilizer Cooperative Limited (IFFCO), is projected to replace the use of urea granules, one of the most widely used fertilizers in the world. Leaf nutrients i.e., nitrogen, phosphorus, potassium and quality parameters i.e., Caffeine, polyphenol were observed after application of nano urea. Leaf nitrogen, leaf phosphorus and leaf potassium were found to be increased with the application of higher dose of Nano Urea. Leaf nitrogen was observed maximum (4.57%) in the plot where 0.4% Nano-urea applied in three sprays. Total phosphorus content of leaf was found to be the highest in treatment T7(0.423%) the lowest was observed in treatment T0 (0.370%). Total potassium content of leaf was the highest in treatment T7 (2.517%) and lowest K2O content was observed in treatment T0 (2.013%) which was a control. In quality parameters, it was found that application of Nano Urea showed significant impact on the total caffeine content of tea leaf. The highest value of caffeine was found in treatment T7 (3.233%) and lowest was found in treatment T0 (3.10%) (control).

Effects of foliar treatments with urea and nano-urea on the cell walls of Monastrell grape skins

Cell wall composition can be affected by nitrogen availability in the vineyard. Foliar application of urea is effective in supplying nitrogen needs and increasing the nitrogen content of musts. Due to the low recoveries of urea fertilisation, more effective application methods such as the use of nanotechnology are needed. In this work, the effect on the composition of Monastrell grape skin cell walls, after foliar application of urea and amorphous calcium phosphate nano-particles doped with urea was studied. The treatments with urea and nano-urea, although the urea content in the nano-treatment was eight times lower than in the conventional treatment, produce an equivalent modification of the cell wall. In fact, both treatments produced an increase in cell wall thickness and in cell wall composition, contents of proteins, hemicellulose and uronic acids also increased. However, phenolic compounds were not affected and cellulose showed lower concentrations than control grapes. Regarding the spectrophotometric parameters of the wine studied, the anthocyanins content and colour intensity were reduced in wines with both treatments and the total polyphenol index was slightly affected.

Response of Sweet Corn to Nano Urea under Precision Nitrogen Management

A lack of synchronization between nitrogen (N) demand and supply results in the loss of applied nitrogen from the soil-plant system. Leaf colour chart (LCC) based nano urea application according to crop specific need has the potential to enhance the crop productivity by reducing N losses. In this context, a field experiment was conducted during summer seasons of 2022 and 2023 on medium black calcareous soil at Junagadh (Gujarat) to study the response of sweet corn to nano urea under precision nitrogen management. Ten treatments comprising 40 kg N as basal (through DAP and urea) + 40 kg N through urea at 25-30 DAS + 40 kg N through urea at 40-45 DAS, 40 kg N as basal + 40 kg N through urea at 25-30 DAS + two foliar spray of nano urea 0.4% (4 ml/l water) when LCC ≤ 4, 40 kg N as basal + 30 kg N through urea at 25-30 DAS + three foliar spray of nano urea 0.4% when LCC ≤ 4, 40 kg N as basal + 20 kg N through urea at 25-30 DAS + four foliar spray of nano urea 0.4% when LCC ≤ 4, 40 kg N as basal + 20 kg N through urea at 25-30 DAS + three foliar spray of nano urea 0.4% when LCC ≤ 4, 40 kg N as basal + 10 kg N through urea at 25-30 DAS + four foliar spray of nano urea 0.4% when LCC ≤ 4, 40 kg N as basal + 10 kg N through urea at 25-30 DAS + three foliar spray of nano urea 0.4% when LCC ≤ 4, 40 kg N as basal + four foliar spray of nano urea 0.4% when LCC ≤ 4, 40 kg N as basal + three foliar spray of nano urea 0.4% when LCC ≤ 4 and control (without N application) in Randomized Block Design with three replications. Based on the results of two-years field study, it can be concluded that higher growth, green cob and fodder yields, quality, net returns and B: C ratio of sweet corn can be obtained by the application of 40 kg N as basal + 40 kg N through urea at 25-30 DAS + two foliar spray of nano urea 0.4% when LCC ≤ 4 or 40 kg N as basal + 30 kg N through urea at 25-30 DAS + three foliar spray of nano urea 0.4% when LCC ≤ 4 or 40 kg N as basal + 40 kg N through urea at 25-30 DAS + 40 kg N through urea at 40-45 DAS.

Nitrogen Fertilization Alleviates Barley (Hordeum vulgare L.) Waterlogging

Waterlogging increasingly challenges crop production, affecting 10% of global arable land, necessitating the development of pragmatic strategies for mitigating the downside risk of yield penalty. Here, we conducted experiments under controlled (tank) and field conditions to evaluate the efficacy of nitrogenous fertiliser in alleviating waterlogging stress. Without intervention, we found that waterlogging reduced grain yields, spike numbers and shoot biomass, but had a de minimus impact on grain number per spike and increased grain weight. Soil fertiliser mitigated waterlogging damage, enhancing yields via increased spike numbers, with crop recovery post-waterlogging catalysed via improved tiller numbers, plant height and canopy greenness. Foliar nitrogen spray has little impact on crop recovery, possibly due to stomatal closure, while modest urea application during and after waterlogging yielded similar results to greater N application at the end of waterlogging. Waterlogging-tolerant genotypes (P-17 and P-52) showed superior growth and recovery during and after waterlogging compared to the waterlogging-sensitive genotypes (Planet and P-79). A comparison of fertiliser timing revealed that field fertilizer treatment two (F2: 90 kg·ha−1 at 28 DWL, 45 kg·ha−1 at sowing and 45 kg·ha−1 at 30 DR) yielded the highest and fertilizer treatment three (F3: 45 kg·ha−1 at sowing and 45 kg·ha−1 at 30 DR) recovered the lowest yield and spike number, while fertilizer treatment one (F1: 45 kg·ha−1 at 28 DWL, 45 kg·ha−1 at 0 DR, 45 kg·ha−1 at sowing and 45 kg·ha−1 at 30 DR) and four (F4: 90 kg·ha−1 at 0 DR, 45 kg·ha−1 at sowing and 45 kg·ha−1 at 30 DR) had the highest shoot biomass in the field. Treatment five (T5: 180 kg·ha−1 at 0 DR, 30 kg·ha−1 at sowing and 90 kg·ha−1 at 30 DR) presented the most favourable results in the tank. Our results provide rigorous evidence that long periods of waterlogging caused significant yield penalty, mainly due to decreased spike numbers. We contend that increasing fertiliser rates during waterlogging up to 90 kg·ha−1 can provoke crop growth and mitigate waterlogging-induced grain yield losses, and is more beneficial than applying nitrogen post-waterlogging.

Effect of foliar application of nano urea on growth, yield and profitability of summer pearl millet (Pennisetum glaucum L.)

Effect of foliar application of nano urea on growth, yield and profitability of summer pearl millet (Pennisetum glaucum L.)

Effect of foliar application of nano urea under different fertility levels on the growth, yield attributes and yield of rice (Oryza sativa L.)

Effect of foliar application of nano urea under different fertility levels on the growth, yield attributes and yield of rice (Oryza sativa L.)

Effect of foliar application of nano urea on growth parameters, yield attributes and yield of mustard (Brassica juncea L.)

Effect of foliar application of nano urea on growth parameters, yield attributes and yield of mustard (Brassica juncea L.)

A comparative assessment of polymer-coated and non-coated urea in direct-seeded rice: agronomic, economic, and environmental performance and sensitivity analysis

The application of polymer-coated urea (PCU) to crops is likely restricted because the product’s capsules cause plastic pollution. Although conventional fertilizer use reduces plastic pollution, it may increase nitrogen (N) pollution owing to its lower N recovery than that of PCU. Therefore, we need to develop optimal N application methods to reduce both plastic and N pollution. Here, we aimed to (1) compare the agronomic, economic, and environmental outcomes of PCU application with those of conventional urea application and (2) provide quantitative targets for developing alternatives to PCU application in dry direct-seeded rice production. We developed a model incorporating yield, brown-rice protein content, farmer profit, and environmental damage cost due to N and polymer loss according to N fertilizer application. Data were collected from field experiments at a farm in Iwate, Japan, from 2020 to 2022. The average apparent N recovery was 0.43 for PCU and 0.37 for conventional urea. Despite the plastic damage cost, the estimated total environmental cost of PCU was lower than that of normal urea owing to the former’s higher N recovery. However, our ability to simulate plastic pollution is limited, as few of the environmental effects of microplastics are understood. If new N application methods with N recovery above 0.5 are developed, an N fertilization cost within $5 × 10–3 g N–1 can maintain the same benefit as that obtained here. This model can be used to evaluate the quantitative relationships among N recovery, benefits, and implementation costs of each candidate N application method.

Analysis of the beneficial effects of prior soybean cultivation to the field on corn yield and soil nitrogen content.

Corn-soybean rotation is a cropping pattern to optimize crop structure and improve resource use efficiency, and nitrogen (N) fertilizer application is an indispensable tool to increase corn yields. However, the effects of N fertilizer application levels on corn yield and soil N storage under corn-soybean rotation have not been systematically studied. The experimental located in the central part of the Songnen Plain, a split-zone experimental design was used with two planting patterns of continuous corn (CC) and corn-soybean rotations (RC) in the main zone and three N application rates of 0, 180, and 360 kg hm-2 of urea in the secondary zone. The research has shown that RC treatments can enhance plant growth and increase corn yield by 4.76% to 79.92% compared to CC treatments. The amount of N fertilizer applied has a negative correlation with yield increase range, and N application above 180 kg hm-2 has a significantly lower effect on corn yield increase. Therefore, a reduction in N fertilizer application may be appropriate. RC increased soil N storage by improving soil N-transforming enzyme activity, improving soil N content and the proportion of soil organic N fractions. Additionally, it can improve plant N use efficiency by 1.4%-5.6%. Soybeans grown in corn-soybean rotations systems have the potential to replace more than 180 kg hm-2 of urea application. Corn-soybean rotation with low N inputs is an efficient and sustainable agricultural strategy.