Prilled Urea Research Articles

The Effect of the Use of a Novel Urease Inhibitor Coated Urea on the Greenhouse Gas Emissions and Ammonia Volatilization Losses from a Maize Field

Nitrogen fertilizers are essential for enhancing agricultural productivity but are also major contributors to greenhouse gas (GHG) emissions and ammonia volatilization, which affect environmental sustainability. This study evaluated the effect of cashew nut shell liquid (CNSL)-coated urea on GHG emissions and ammonia losses from maize fields in the Indo-Gangetic Plains, known for excessive nitrogen fertilizer usage. A randomized block design was employed with four treatments: control (no nitrogen), prilled urea, neem-coated urea (NCU), and CNSL-coated urea (CCU). Gas samples were collected using the closed chamber method, and emissions of CO₂ and N₂O were analyzed via gas chromatography. Ammonia volatilization was measured using the forced air draft method. Results showed that the CCU treatment significantly reduced ammonia volatilization compared to prilled urea (15.84% reduction), with reductions of 9% to those observed with NCU. Moreover, CCU-treated plots exhibited reduced cumulative GHG and lower global warming potential (GWP) without compromising maize yields. Cumulative GHG emissions varied among the treatments in the order urea> CCU> NCU> Control. CCU treated plots exhibited a net GWP decrease of 8.59% compared to urea and an increase of 4.13% compared to NCU. These findings suggest that CNSL-coated urea can serve as an eco-friendly alternative to conventional urea, potentially mitigating environmental impacts associated with nitrogen fertilization. Further studies are recommended to assess the long-term efficacy of CNSL in various soil types and climatic conditions.

Different Nitrogen Levels with Nano and Prilled Urea Spray on Productivity and Profitability of Maize (Zea mays L.) in alfisols of Jharkhand

A ground-breaking and enduring way to significantly reduce the use of conventional nitrogen fertilizer is to use nano-urea as a nitrogen supplement. The combination of nano and prilled urea was investigated in this study to address this issue and allowing for a 25% reduction in the recommended urea dosage. Research on rainfed maize during kharif season was conducted at ICAR-IARI Jharkhand. Twelve different combinations of conventional prilled urea, nano and prilled urea spray were investigated in the study. In the fields, the experiment used a randomized block design. Different treatments included applying prilled urea as a 2% solution in 150 liters of water per hectare and nano-urea at a rate of 1250 ml/acre applied twice through foliar application. Results showed that applying two additional applications of nano-urea along with 75% of the recommended dose of prilled-urea was the most successful fertilization strategy. This performed statistically equal with both the 100% recommended dose and the 100% recommended dose with two prilled urea spray applications in terms of yield, and cost-to-benefit ratio. The study's findings show that nano-urea can safely replace at least 25% of the dosage of prilled urea i.e. recommended, providing a more profitable and environmentally friendly method of cultivation.

Efficacy of Nano Urea on Nitrogen Use Efficiency of Irrigated Maize under Temperate Ecology

A field experiment was conducted during the Kharif-2022 season at the Agronomy Research Field, FOA, SKUAST-Kashmir, to investigate the efficacy of nano-urea in improving nitrogen-use efficiency in irrigated maize. Ten treatments were evaluated viz., T1: Control, T2: Recommended dose of Nitrogen (RDN) as basal (prilled urea), T3: 75% RDN + 1 spray nano-urea at 2 ml L-1 (60 DAS), T4: 75% RDN + 1 spray at 4 ml L-1 (60 DAS), T5: 50% RDN + 2 sprays at 2 ml L-1 (30 and 60 DAS), T6: 50% RDN + 2 sprays at 4 ml L-1 (30 and 60 DAS), T7: 25% RDN + 2 sprays at 6 ml L-1 (30 and 60 DAS), T8: 25% RDN + 2 sprays at 8 ml L-1 (30 and 60 DAS), T9: 25% RDN + 1 spray at 6 ml L-1 (60 DAS), T10: 25% RDN + 1 spray at 8 ml L-1 (60 DAS). The experiment was carried out following a randomized complete block design with three replications. Results revealed that treatment T6 (50% RDN as basal + 2 sprays at 30 and 60 DAS at 4 ml L-1 of nano-urea) exhibited superior performance compared to the recommended nitrogen dose (T2) and other treatments in enhancing nutri-ent-use efficiency. Notably, treatment T6 demonstrated the highest nitrogen uptake in grain (101.92 kg ha-1) as well as stover (67.41 kg ha-1), surpassing all other treatments. Additionally, agronomic efficiency was significantly higher in T8, while physiological efficiency peaked in T6. Yield attributes and overall yield showed consistent improvements in treatments receiving nano-urea. Furthermore, treatments utilizing nano-urea demonstrated higher net returns and benefit-cost ratios, with T6 particularly standing out. These findings underscore the potential of foliar application of nano-urea to halve the recommended dose of prilled urea, thereby enhancing nitrogen uptake, nutrient-use efficiency, yield, and economic returns, while promoting sustainability in agriculture.

Effect of Nano-Urea Based Nitrogen Application on the Growth, Phenology and Yield of Direct Seeded Rice (Oryza sativa L.)

As large quantum of urea is used in the rice crop, there is a need to reduce atleast some portion of prilled urea to minimize the nitrogen losses besides improving the growth and yield of rice. With this rationale, a field experiment was carried out in the Kharif season of 2022 at the Agronomy Research Farm in Sher-e-Kashmir University of Agricultural Sciences and Technology- Kashmir, India to study the efficiency of Nano-urea over prilled urea in direct-seeded rice. The experimental study comprised of nine treatments viz.,T0 (Control), T1 (recommended dose of prilled urea), T2 (NU 2 sprays at 6 ml L-1 at AT and PI stage), T3 (NU 2 sprays at 8 ml L-1 at AT and PI stage), T4 (50 % RDPU as basal + NU 2 sprays at 2 ml L-1 at AT and PI stage), T5 (50 % RDPU as basal + NU 2 sprays at 4 ml L-1 at AT and PI stage), T6 (25 % RDPU as basal + NU 2 sprays at 2 ml L-1 at AT and PI stage), T7 (25 % RDPU as basal + NU 2 sprays at 4 ml L-1 at AT and PI stage), T8 (25 % RDPU as basal + NU 2 sprays at 6 ml L-1 at AT and PI stage) and T9 (25 % RDPU as basal + NU 2 sprays at 8 ml L-1 at AT and PI stage) which were arranged in randomized complete block design and replicated three times. These treatments included the application of Nano-urea in addition to conventional nitrogen dosages of 120 kg ha-1 and control treatments (no application). T5 (50 % RDPU as basal + NU 2 sprays at 4 ml L-1 at AT and PI stage) was the treatment that most significantly improved growth characteristics out of all of them, with a notable achievement of a Leaf Area Index (LAI) of 4.51. In addition, T5 performed superior to other treatments in yield-related parameters like panicle weight (2.69 g), yield (66.57 q ha-1). These findings demonstrate the significant potential of Nano-urea to maximize nitrogen use and increase yield in direct-seeded rice farming systems.

Enhancing Yield and Nitrogen Utilization of Boro Rice with Urea Super Granules

A field experiment was conducted at the Soil Science Field Laboratory of Bangladesh Agricultural University, Mymensingh during boro season to assess the comparative performance of prilled urea (PU) and urea super granule (USG) on the growth, yield, and nitrogen uptake of BRRI dhan29. The experiment was laid out in a randomized complete block design with three replications. The treatment combinations were T1: Control, T2: PU at 7 days after transplanting (DAT)+27 DAT+47 DAT, T3: PU at 10 DAT+30 DAT+50 DAT, T4: PU at 15 DAT+35 DAT+55 DAT, T5: USG at transplanting, T6: USG at 7 DAT, T7: USG at 10 DAT and T8: USG at 10 DAT+30 DAT where PU and USG were applied @ 216 kg N ha-1. PU was applied as surface broadcasting whereas USG was placed at 6-8 cm depth by hand between four hills at every alternate row. The results revealed that all the treatments showed better performances than control (T1). Results found that yield components, yield, and nitrogen uptake of BRRI dhan29 responded significantly to deep placement of USG than PU. Treatment T6 (USG at 7 DAT) produced the highest grain and straw yields of 6.56 t ha-1 and 6.95 t ha-1 respectively. Treatment T6 (USG at 7 DAT) also showed the highest grain yield increase (57.16%) and straw yield increase (52.37%) over control. The highest grain, straw, and total N uptake of 87.28, 32.71 and 120 kg ha-1 respectively were obtained in the treatment T6 (USG at 7 DAT). The overall results clearly indicate that deep placement of USG at 7 DAT in rice field increases rice yield and efficient uptake of the applied N. So, treatment T6 (USG at 7 DAT) could be recommended as best treatment for reducing N losses, conserving environment and improving sustainable production of rice.

Dual inhibitors for mitigating greenhouse gas emissions and ammonia volatilization in rice for enhancing environmental sustainability

The use of inhibitors retain nitrogen as ammonium in soil, giving plants ample time for its uptake. This can reduce nitrous oxide (N2O) emissions, but extended retention may increase ammonia (NH3) volatilization. This study assessed the efficacy of coated urea fertilizers in reducing greenhouse gas (GHG) emissions and NH3 volatilization in rice fields. A field experiment with Pusa 44 rice in the kharif seasons of 2019 and 2020 compared unfertilized control (No N), prilled urea (PU), nitrification inhibitors (NIs): neem oil-coated urea (NCU), karanj oil-coated urea, and dual inhibitor (DI: Limus + NCU). The coated urea fertilizers were analysed with scanning electron microscopy, fourier transform infrared spectrometry, and energy-dispersive spectroscopy. Compared to PU, DI reduced N2O emissions by 23.7%, methane by 11.9%, and NH3 by 29.8%. DI also reduced NH3 emissions by 36–39% compared to other NIs. Overall, DI can lower the global warming potential of rice cultivation in trans Indo-Gangetic plains region by 17.1% for both direct and indirect emissions, suggesting its significant potential to reduce India's contribution to total agricultural GHG emissions.

Relative Efficiency of Prilled Urea, Urea Super Granules (USG), and Neem-Coated Urea (NCU) for Growth and Yield of Wheat

The experiment took place at the net house of the Agronomy field laboratory, Department of Agronomy and Agricultural Extension, University of Rajshahi, from November 2019 to March 2020, aiming to determine the relative efficiency of prilled urea, urea super granules (USG), and neem-coated urea (NCU) for wheat growth and yield. Five different nitrogenous fertilizers were included: BARC recommended prilled urea at 0.5 g/pot (T1), urea super granules (USG) at 0.25g/pot (T2), neem-coated urea at 0.25g/pot (T3), urea super granules (USG) at 0.5g/pot (T4), and neem-coated urea at 0.5g/pot (T5). The experiment followed a Randomized Block Design (RBD) with three replications. Results indicated significant effects of nitrogenous fertilizer forms on wheat growth and yield characteristics. Across most parameters, the highest values were observed in T5, utilizing 0.5g of neem-coated urea per pot, including plant height (77.34 cm), number of tillers (6.14), effective tillers per pot (23.04), extrusion length (16.57), spike length (17.25), filled grains per pot (1093.43), 1000-grain weight (42.22 g), grain yield (46.39 g/pot), straw yield (77.81g/pot), and biological yield (124.20g/pot). Based on these findings, we can conclude that applying 0.5 g of neem-coated urea per pot (T5) was the most effective treatment for enhancing wheat growth and yield among the tested options.

Performance of basmati rice (Oryza sativa) under variable irrigation and nitrogen management

A field experiment was conducted during the rainy seasons (kharif) of 2021 and 2022 at research farm of ICAR- Indian Agricultural Research Institute, New Delhi to study the effect of irrigation regimes and integrated use of prilled urea and nano-urea as a source of N, on productivity and profitability of basmati rice (Oryza sativa L.). The experiment was conducted in a three-time replicated split-plot design (SPD) comprised of 3 irrigation regimes, viz. irrigation at 1, 3 and 6 days after disappearance of surface water (DADSW) assigned to main-plots and 4 N-management variants including; 100% RDN (recommended dose of N, 120 kg/ha); 75% RDN + 4% nano-urea (NU) 2 sprays (75% RDN + 2 NU); 50% RDN + 2 NU; and no-N (control) in sub-plots. Irrigating basmati rice 1 DADSW exhibited the highest panicle weight (2.67–3.09 g) and number of grains/panicle (115.9, 109.8), across the years, respectively that were significantly higher than 3 and 6 DADSW. The most delayed irrigation at 6 DADSW caused significant reduction in grain yield, the magnitude of reduction was 13–19% over irrigation at 3 DADSW and substantially by 23–28% over 1 DADSW. Fertilizing rice crop with 100% RDN and 75% RDN + 2 NU resulted in statistically similar yield attributes and grain yield; however, both were, significantly superior to 50% RDN + 2 NU and no-N. Net returns, benefit cost (B:C) ratio and monetary efficiency were significantly higher when crop was irrigated 1 DADSW than 3 and 6 DADSW. The N-management options followed the trend as RDN>75% RDN + 2 NU ˃50% RDN > no-N for all studied economic parameters.

Assessing the Impact of Coated and Prilled Urea Fertilizers on Nitrogen Dynamics and Fodder Maize Yield in Alfisols

The study investigates the impact of different urea fertilizers on nitrogen mineralization, leaching losses, and growth, yield of fodder maize in Alfisols. Nitrogen is vital for plant growth but deficient in soils. Urea, a widespread nitrogen fertilizer, suffers from significant losses, prompting the development of controlled-release urea (CRU) fertilizers. This study assesses various urea formulations with coated urea and prilled urea. Laboratory incubation studies show that coated urea exhibits slower NH4+-N release, reducing losses and improving efficiency compared to uncoated urea. Nitrate content increases steadily periodically with coated urea, potentially enhancing nitrogen availability to plants. Greenhouse experiments reveal significant differences in plant height, leaf number, and leaf area among treatments. Coated urea formulations, chiefly CSPC @3%, demonstrate superior growth parameters (plant height-169.56cm, number of leaves-10.33 and leaf area-1850.59), yield (green fodder-328.25 gplant-1, dry fodder-198.61 gplant-1 and dry matter percentage-54.52) and quality parameters (crude protein-4.03, total ash content-3.82%) compared to prilled urea growth parameters (plant height-113.38cm, number of leaves-8.07 and leaf area-1670.98), yield (green fodder-246.26 gplant-1, dry fodder-116.35 gplant-1 and dry matter percentage-44.32) and quality parameters (crude protein-2.88, total ash content-2.75%), likely due to sustained nitrogen release. Higher nitrogen availability from coated urea leads to increased forage yield and quality. The findings suggest that coated urea fertilizers, specially CSPC @3% advocate improved nitrogen management, enhancing fodder maize productivity and sustainability.

Modelling and optimization of urea super granule (USG) placement depth in paddy cultivation under check basin irrigation using HYDRUS-2D model

Urea, a nitrogenous fertilizer which plays an important role in enhancing yield, but has a drawback of low nitrogen use efficiency (NUE). Use of urea super granule (USG) and coated urea have advantages over prilled urea in terms of higher NUE and eventually improved yield. Depth of placement (DOP) of USG plays a major role in achieving higher NUE and yield. However, appropriate depth of placement needs detailed knowledge about water and nitrogen (N) movements to provide maximum nutrient to plants. Therefore, an experiment was conducted in the paddy field using USG coated with three different types of coating (USG with nano bentonite and neem oil (T1), USG with heated nano bentonite and neem oil (T2) and USG with sulfer and acacia gum solution (T3)) and placed at the centre of four hills of paddy as basal dose at ICAR-IARI, New Delhi. Spatial and temporal data of soil moisture and Nwere collected for the initial 32 days in paddy field after crops establishment. The HYDRUS-2D model was calibrated and validated using the observed data. Calibrated model was used for simulation of N movement in different soil types and for different depths of USG placement. Results revealed that permissible soil like sandy loam, the optimum DOP irrespective of coating was 5 cm. For sandy clay loam soil, optimum depth of placement was found to be 10 cm, 6 cm and 10 cm for T1, T2 and T3 type of coatings. Similarly, for clay loam soil, depth of USG placement for T1, T2 and T3 type coating was found to be 8 cm, 10 cm and 8 cm, respectively. Using the optimum DOP in sandy clay loam soil, results showed that both i.e., DOP and coating type has significant effect on number of tillers m−2 and yield (t ha−1). In 2020 and 2021, the highest number of tillers per square meter at 30 days after transplanting (DAT) was observed in the T3 treatment at DOP of 10 cm, with counts of 453.66 and 454.88, respectively. Following closely were T2 at DOP of 10 cm (447.33 and 119.55) and T1 at DOP of 6 cm (443.44 and 444.77). Similarly, the best yield in 2020 and 2021 were observed from T3 treatment at DOP of 10 cm (5.41 t/ha and 5.44 t/ha), followed by T2 at DOP of 10 cm (5.33 t/ha and 5.42 t/ha), and T1 at DOP of 6 cm (5.29 t/ha and 5.31 t/ha). This study may assist the farmers, researchers, manufacturers and policy makers to make selection of the optimum depth of placement for higher NUE and yield in different soil types.

Optimising nitrogen use efficiency of prilled urea through integrated use of nano-ZnO and green manuring for better productivity, quality and nutritional status of Basmati rice crop

In agricultural systems, significant nitrogen (N) losses from traditional fertilizers pose risks to food security and economic stability. An emerging approach to mitigate these losses involves nanoparticles (NPs) coatings onto urea, aiming to enhance N availability and consequently boost crop yields. To explore the most effective and sustainable N management strategies, a field experiment was carried out in Basmati rice at the ICAR-Indian Agricultural Research Institute, New Delhi, India over 2020–2021 in a split-plot design, with two summer green manure (GM) types-Sesbania (G2) and cowpea (G3) and fallow in the main plot and six nitrogen fertilization (NF) modules, i.e., 0 kg N + 5 kg Zn ha−1 through bulk ZnO (N1), N through prilled urea (PU) (N2), N through PU + 5 kg Zn ha−1 through bulk ZnO (N3), 1% bulk ZnO-coated urea (1% BZnCU) (N4), 0.1% nano ZnO-coated urea (0.1% NZnCU) (N5) and 0.2% nano ZnO-coated urea (0.2% NZnCU) (N6) in subplots replicated three times. The objectives of the study was to identify the optimal GM crops and the most effective NF modules on enhancing plant height, dry biomass, grain yield, milling quality, and N, P, K nutrition, as well as nitrogen use efficiency (NUE). Our findings demonstrated that, a significant enhancement in plant height (13.34%) and dry biomass (38.1%) at harvest was observed with the combined application of G2 and N6 when juxtaposed against G1 and N1. The pooled analysis revealed that GM enhanced grain yield by 12.75% in comparison to G1, irrespective of the NF modules employed. The Sesbania was identified as the top-performing GM, registering a yield 17.5% greater than fallow while it was 8.13% for cowpea. Among NF modules, there was a noted 10.03% yield increase when urea was zinc-coated compared to using only urea (N2), and a 33.75% increase against the N1. The application of N6 modules boosted hulling, milling, and head rice recovery by 3.73, 4.45, and 4.98%, respectively, compared to N1. Moreover, combining zinc with urea raised the N content in milled rice by approximately 9.1% and heightened the N, P, and K concentration in the straw by 22.8, 4.44, and 11.8%, and total N, P, and K uptake by 5.72, 3.33, and 11.7%, in comparison to the combined effect of N1 and N2. Considering the NUE metrics, such as partial factor productivity (PFP), agronomic efficiency (AE), recovery efficiency (RE), and physiological efficiency (PE), the application of GM showcased superior performance in PFP and RE against the G1, while AE and PE remained unaffected. The G2 as a GM, performed best in PFP and RE. The N5 module delineated the most substantial advancements in NUE indices, despite being comparable to N6. In conclusion, the adoption of Sesbania as a green manure crops, coupled with the 0.2% nano ZnO-coated urea module, is identified as an efficient method for maximizing growth, yield, milling attributes, nutrient assimilation, and overall NUE in the Basmati rice.

Optimizing Nitrogen Sources in Top Dressing for Wheat: Field Study on Growth, Yield, and Ammonia Volatilization.

In alkaline calcareous soils, ammonia volatilization is the primary nitrogen (N) loss process, resulting in the reduced N use efficiency of crops. This study aimed at assessing the impact of different N sources for top dressing on ammonia volatilization, as well as their effects on wheat growth and yield over two years. In each year, half of the recommended N was applied as a basal dose using diammonium phosphate (DAP) and urea. The remaining half was top-dressed 35 days after sowing with various sources: prilled urea (PU), granular urea (GU), ammonium sulfate (AS), and calcium ammonium nitrate (CAN) in the first year; PU, urea coated with a urease inhibitor from 20 g (VnU-20) and 40 g (VnU-40) leaves of Vachellia nilotica, biochar-coated urea (BU), and urease inhibitor paraphenylenediamine-coated urea (PPDU) in the second year. Ammonia volatilization losses were tracked for up to 12 weeks from sowing. Ammonia losses from basal-applied N remained consistent in both years, comprising around 4% of the applied N. In the first year, top-dressed AS resulted in the highest losses, followed by GU, while losses from urea and CAN were statistically similar. In the second year, coated fertilizers showed lower ammonia losses compared to PU, with VnU-40 displaying the least losses, 48% less than PU. Nitrogen concentration in wheat grain and straw exhibited a negative correlation with ammonia losses. The choice of top-dressed N source influenced tillering, biological, straw, and grain yields of wheat. In the first year, CAN provided maximum yield benefits, and in the second year, VnU-20 exhibited 27% more grain yield than PU. These findings suggest that top dressing with coated urea, especially VnU-20, has the potential to reduce ammonia losses, improve crop nitrogen status, and enhance economic yield compared to other nitrogen sources.

Effect of Integrated Use of Poultry Manure with Fertilizer Urea for Sustainable Nitrogen Management in Rice (cv. BRRI Dhan 29) under Two Water Management Systems

The experiment was conducted at the Agronomy Field Laboratory, Bangladesh Agricultural University, Mymensingh. The experiment's objectives were to evaluate the performance of integrated management of poultry manure with chemical fertilizer urea and to seek water-saving technology that will allow rice (BRRI dhan 29) production to be maintained or increased in the face of declining water availability. The experiment comprised seven treatments viz. T1:100% N from poultry manure, T2:100% N recommended doses of prilled urea, T3:90% N from PU + 10% N from PM, T4:80% N from PU + 20% N from PM, T5: 70% N from PU + 30% N from PM, T6: 60% N from PU + 40% N from PM, T7: 50% N from PU + 50% N from PM. It was laid out in a split-plot design with three replications. The main plots were allocated for irrigation treatments (alternate wetting and dying and continuous flooding) and sub-plots for nitrogen treatments. Altogether, 42 unit plots were conducted, each measuring 2.5mx2.5m. The application of different nitrogen levels significantly influenced all the growth parameters. Irrigation levels significantly affected all the yield and yield contributing characters except plant height, number of ineffective tillers, panicle length, unfilled grain per panicle, 1000 grain weight and harvest index. The highest value of total tiller/hill (11.01), number of effective tillers per hill (9.72), filled grain per panicle (132.23), grain yield (4.80), straw yield (6.68), biological yield (11.47) was observed in the two-irrigation system while height value of non-effective tiller/hill (1.29). The effect of nitrogen treatment was found to be significant. On the other hand, the interaction effect of irrigation management and treatments significantly influenced all the yield parameters except plant height, No. of tiller/ hill, no. of non-effective tiller/hill, panicle length, unfilled grain/panicle and 1000 grain weight. The height value of all those parameters was recorded at the I1×T2 (continuous flooding ×100% N recommended doses of prilled urea). The lowest value of all these parameters was recorded at the I2×T1 (AWDI × 100% N from poultry manure) and I1×T1 (continuous flooding × 100% N from poultry manure). The integrated use of 90% N from PU + 10% N from PM appeared as the better practice because of reducing the considerable amount of prilled urea in Boro rice (cv. BRRI dhan 29) cultivation in terms of grain yield. Moreover, the best promising practice was obtained using 100% N recommended doses of prilled urea applied with continuous flooding (CF).

Effects of integrated plant nutrition systems with fertilizer deep placement on rice yields and nitrogen use efficiency under different irrigation regimes

Improved fertilizer management, with a combination of organic and inorganic inputs, has the potential to enhance rice yield while maintaining soil health. However, studies on the effects of broadcast prilled urea (PU) and urea deep placement (UDP) applied in combination with organic inputs (poultry litter [PL] and vermicompost [VC]), as integrated plant nutrition systems (IPNSs), on rice yields and nitrogen use efficiency (NUE) under alternate wetting and drying (AWD) irrigation are limited. We conducted field experiments during the dry and wet seasons of 2018, 2019, and 2020 to investigate the effects of fertilizer treatments, including control (no nitrogen), UDP, PU, and IPNSs (PU + VC, PU + PL, and UDP + PL) on rice yield and NUE under two irrigation regimes – AWD and continuous flooding (CF). The results revealed that fertilizer treatment and irrigation regime had significant (p < 0.05) interaction effects on rice yield and the agronomic efficiency of N (AEN) during the dry season. UDP significantly (p < 0.05) boosted rice yield, total dry matter (TDM), and NUE as compared to broadcast PU in both wet and dry seasons. Similarly, the IPNS treatment of UDP with PL significantly (p < 0.05) boosted rice yield, TDM, and NUE in comparison to broadcast PU. Under AWD irrigation, UDP alone produced higher rice yields than other treatments, while UDP, and UDP with PL produced similar yields under CF irrigation. During the dry season, AWD irrigation significantly (p < 0.05) increased rice yield, TDM, and AEN when compared to CF conditions, but during the wet season, AWD irrigation demonstrated a rice yield and NUE equivalent to CF. This research implies that using a UDP alone or in combination with PL as an IPNS could be a good way to boost crop productivity while also maintaining soil fertility.

Morpho-physiological and yield attributes of boro rice varieties as influenced by different nitrogen sources

The present study was carried out at the Research Field of Sher-e-Bangla Agricultural University (SAU), Dhaka during Boro season, 2021-2022 to discover the best nitrogen source for enhancing Boro rice grain production. The experiment consisted of two factors: A) Three varieties: BRRI dhan29 (V1), BRRI dhan58 (V2), and Heera (V3). B) Four nitrogen sources: no nitrogen (T1), BRRI-recommended prilled urea (T2), recommended dose of mixed NPK (T3), and BARC-recommended USG (T4). The experiment was laid out in split plot design with three replications where main plot was for nitrogen source and subplot was for variety. USG treatment resulted in the highest grain production (8.6 t/ha) and the lowest percentage of spikelet sterility of any nitrogen source tested. Except for harvest index, all of the examined characteristics differed considerably between types. This is mostly due to BRRI dhan29 having the maximum number of full grains (98.8/panicale) and a significantly lower degree of spikelet sterility (7.3%). Among the interaction effects, the combination of the USG application with BRRI dhan29 showed the greatest performance in terms of delivering the maximum grain production (9.3 t/ha) by significantly reducing spikelet sterility. Res. Agric. Livest. Fish. Vol. 10, No. 2, August 2023: 175-182

Conjoint application of nano-urea with conventional fertilizers: An energy efficient and environmentally robust approach for sustainable crop production.

One of the biggest challenges to be addressed in world agriculture is low nitrogen (N) use efficiency (<40%). To address this issue, researchers have repeatedly underlined the need for greater emphasis on the development and promotion of energy efficient, and environmentally sound novel fertilizers, in addition to improved agronomic management to augment nutrient use efficiency for restoring soil fertility and increasing farm profit. Hence, a fixed plot field experiment was conducted to assess the economic and environmental competency of conventional fertilizers with and without nano-urea (novel fertilizer) in two predominant cropping systems viz., maize-wheat and pearl millet-mustard under semi-arid regions of India. Result indicates that the supply of 75% recommended N with conventional fertilizer along with nano-urea spray (N75PK+nano-urea) reduced the energy requirement by ~8-11% and increased energy use efficiency by ~6-9% over 100% nitrogen through prilled urea fertilizer (business as usual). Furthermore, the application of N75PK+ nano-urea exhibited ~14% higher economic yields in all the crops compared with N50PK+ nano-urea. Application of N75PK+nano-urea registered comparable soil N and dehydrogenase activities (35.8 μg TPF g-1 24 hrs-1 across all crops) over the conventional fertilization (N100PK). This indicates that application of foliar spray of nano-urea with 75% N is a soil supportive production approach. More interestingly, two foliar sprays of nano-urea curtailed nitrogen load by 25% without any yield penalty, besides reducing the greenhouse gases (GHG) emission from 164.2 to 416.5 kg CO2-eq ha-1 under different crops. Therefore, the application of nano-urea along with 75% N through prilled urea is an energy efficient, environmentally robust and economically feasible nutrient management approach for sustainable crop production.

Influence of nitrogen sources on grain yield of wheat and net global warming potential

ABSTRACT Nitrous oxide (N2O) emission is mainly associated with aerobic crop culture, which is influenced by nitrogen (N) fertilizer sources, rates, placement methods, and water management systems. The influence of N fertilizers on greenhouse gas (GHG) emission patterns are not well documented in Asian region. The present investigation was undertaken to identify GHG emission patterns, net carbon budget, net global warming potential (GWP) and GHG intensity. N fertilizer from prilled urea (PU), urea super granule (USG) and N-phosphorus (P)-potassium (K) briquette (NPKB) were used and compared with control (no fertilizer). Equal nutrient doses were maintained for all the treatments irrespective of fertilizer sources. Static close chamber technique was used for measuring GHG emission. Depending on treatments, total methane (CH4), nitrous oxide and carbon dioxide (CO2) fluxes were 8.16–10.85, 0.57-0.49-0.59 and 1739–2309 kg ha−1 season−1, respectively and net GWPs varied from −1292 to −2438 kg CO2 eq. ha−1 season−1. Wheat grain yields significantly varied from 3.2 to 3.9 t ha−1 because of N sources and rates. Use of USG for wheat cultivation can increase CO2 removal about 22–88% from the atmosphere along with about 2–14% grain yield and 26–48% soil organic carbon (SOC) sequestration improvements compared to other N sources in Bangladesh.

Influence of nitrogen sources and rates on yield and nitrogen use efficiency of tomato

A study was carried out with tomato at the research field of Regional Agricultural Research Station of BARI, Cumilla during two consecutive years 2019-20 and 2020-21. The objective was to evaluate the yield response and nitrogen use efficiency (NUE) of tomato (variety BARI Tomato-15) and to suggest the source and the rate of N fertilizer recommendation for tomato. The experiment was laid out in a RCBD design with three N sources (PU, NCU and DAP) and two N rates (100% and 125% of recommendation as per FRG-2018) replicated three times. In the first year, prilled urea (PU), neem coated urea (NCU) and DAP were used but in the second year DAP was replaced by urea super granule (USG). The recommended dose of N for tomato was 120 kg ha-1. Results revealed that between two rates of N application the yield was the maximum (77.4 t ha-1 and 60.3 t ha-1 in two years, respectively with 125% of RD. The highest agronomic use efficiency of nitrogen (NAUE) was obtained from 100% RD of N as DAP (150.0 kg kg-1) and 125% RD of N as NCU (133.3 kg kg-1). The lowest N use efficiency was observed in 100% PU (84.2 kg kg-1) and 100% NCU (40.8 kg kg-1) treated plots. Due to optimal plant growth, the neem-coated urea treatment yielded little higher than PU treatment. Bangladesh J. Agri. 2023, 48(1): 92-100

Corn Cropping System and Nitrogen Fertilizers Technologies Affect Ammonia Volatilization in Brazilian Tropical Soils

The adoption of technologies for N fertilization has become essential for increasing the N use efficiency in no-till (NT) systems in Brazil. Thus, this study aimed to quantify ammonia losses, N removal in grains, and second crop season yield in no-till and conventional (T) areas that received the application of different N fertilizers and their technologies. Ammonia volatilization, N extraction in grains, and corn yield in response to the application of conventional fertilizers were compared to urea treated with urease inhibitors in NT and conventional systems. The treatments were: no-N (Control); Prilled urea (PU); urea + N-(n-Butyl) thiophosphoric triamide (UNBPT); urea + Cu + B (UCuB); ammonium nitrate (AN), and ammonium sulfate (AS). In the NT system, the N-NH3 losses were 49% higher than in the conventional; without differences in corn yield. The fertilizers AN and AS had the lowest N-NH3 losses, regardless of the tillage system. UNBPT reduced the mean N-NH3 loss by 33% compared to PU. UNBPT (1200 mg kg−1) and UNBPT (180 mg kg−1) reduced the N-NH3 losses by 72% and 22%, respectively, compared to PU in the NT system. We noticed that the NBPT concentration to be used in soils under NT should be adjusted, and a reduction of N-NH3 losses does not directly reflect an increase in yield and N extraction by corn.

Interplay between nano zinc oxide-coated urea and summer green manuring in basmati rice under basmati rice-wheat cropping system: implications on yield response, nutrient acquisition and grain fortification

Identifying appropriate nutrient management options is crucial for reversing the yield plateau and enhancing the nutritional status of basmati rice under the basmati rice-wheat cropping system of the Indo Gangetic Plain (IGP). Alternative to the conventional chemical fertilizer, ZnO nanoparticles as carrier material for the micronutrient Zn has shown promise in reducing the bulkiness of fertilizer use in the soil–plant environment. But whether its integration and interaction with an organic source such as green manuring could enrich basmati rice grain with micronutrients and promote protein nutrition is not well investigated. Therefore, we conducted a field experiment during the summer and rainy seasons (April–October) of 2020 and 2021 at the research farm of the ICAR-Indian Agricultural Research Institute, New Delhi in a split-plot design with two summer green manuring (SGM) options (Sesbania and cowpea, along with fallow) as main plots and six fertilization strategies as subplots: 5 kg Zn ha−1 as bulk ZnO, N at 120 kg N ha−1 as prilled urea (PU), N at 120 kg N ha−1 as PU + 5 kg Zn ha−1 as bulk ZnO, 1% bulk ZnO-coated PU, 0.1% nano ZnO coated PU and 0.2% nano ZnO coated PU replicated thrice. On average, SGM increased basmati rice grain yield by 13.2 and 12.3% during 2020 and 2021, respectively compared to fallow. Integrated application of zinc with urea significantly (p &amp;lt; 0.05) increased the grain yield of basmati rice by 9.56% and by 10.5% relative to urea without zinc and by 33.7 and 33.8% than the sole application of 5 kg Zn ha−1 through ZnO, respectively during 2020 and 2021. On average, SGM boosted Zn, Cu, Mn, and Fe content in milled rice by 25, 22.38, 20.0, and 18.85% during 2020 and 23.75, 21.4, 19.6, and 13.3% during 2021, respectively compared to fallow. Relative to sole urea application, zinc, and urea together improved the Zn and Fe content in milled rice by 2.99 mg kg−1 and 2.62 mg kg–1, respectively during the first year and by 2.83 mg kg−1 and 2.6 mg kg−1, respectively during the second year of study. The highest protein content in basmati rice grain was observed when it was grown after Sesbania aculeata residue incorporated plot during both the years and it decreased in the order: Sesbania aculeata &amp;gt; Vigna unguiculata &amp;gt; summer fallow. Our findings revealed that with the application of 1% bulk ZnO coated PU with Sesbania; the yield response, micronutrient acquisition, and protein accumulation in milled rice was higher than in other plant fertilization methods. However, in plots treated with Sesbania, along with 0.2% nano ZnO-coated PU exhibited statistically equivalent yield and micronutrient loading in edible tissues. Hence, this study unveils the critical role of nano ZnO-coated urea and summer green manuring in elevating micronutrient and protein bioavailability in basmati rice and concurrently reducing Zn dose by 20%, making it a profitable option for farmers.