Conventional Urea Research Articles

Effect of Foliar Application of Nano and Conventional Urea on Nitrogen Uptake and Use Efficiency in Ragi (Eleusine coracana)

A field trial was carried out at Agricultural and Horticultural Research Station, Bavikere, Shivamogga, India, during Late Kharif 2022 to study the Effect of foliar application of nano and conventional urea on nitrogen uptake and use efficiency in ragi. The treatments consists of absolute control (T1), recommended dose of fertilizer (T2), 50 per cent RDN + two sprays of 0.4 per cent nano urea fertilizer at 30 & 45 DAT (T3), 75 per cent RDN + one spray of 0.4 per cent nano urea fertilizer at 30 DAT (T4), 75 per cent RDN + two sprays of 0.4 per cent nano urea fertilizer at 30 & 45 DAT (T5), 100 per cent RDN + one spray of 0.4 per cent nano urea fertilizer at 30 DAT (T6), 50 per cent RDN + two sprays of 2 per cent urea fertilizer at 30 & 45 DAT (T7), 75 per cent RDN + one spray of 2 per cent urea fertilizer at 30 DAT (T8), 75 per cent RDN + two sprays of 2 per cent urea fertilizer at 30 & 45 DAT (T9), 100 per cent RDN + one spray of 2 per cent urea fertilizer at 30 DAT (T10), four sprays of 0.4 per cent nano urea fertilizer at 15, 30, 45 & 60 DAT (T11). The results showed that the application of 100 per cent RDN + one spray of 0.4 per cent nano urea fertilizer at 30 DAT recorded higher total dry matter accumulation (46.75 g hill-1), absolute growth rate (0.64 g day-1), crop growth rate (21.39 g m-2 day-1), grain yield (3812 kg ha-1) and total nitrogen uptake (89.60 kg ha-1) as compared to other treatmnets and it was statistically on par with the T10 and T5. The Treatment T5 recorded higher nitrogen use efficiency (48.41 %) compared to other treatments.

Effect of Different Level of Nano Urea on Growth of Strawberry (Fragaria X ananassa) cv. Winter Dawn, under Prayagraj Agro Climatic Conditions

A research study was carried out at the Horticulture Research Farm, Department of Horticulture, NAI, SHUATS, located in Prayagraj, Uttar Pradesh, during the academic years 2022-23 and 2023-2024. The experiment comprised 11 treatments involving various combinations of conventional urea and nano urea, applied at different levels and concentrations, with each treatment replicated three times in a Randomised Block Design. The main objective of the experiment was to assess the impact of varying concentrations of nano urea on the growth characteristics of Strawberry (Fragaria X ananassa) cv. Winter Dawn. Treatment T7 [100% PK + 60% RDN + 0.8% Nano urea (8 ml/l)] was found best with [9.78 (2022-23), 10.05 (2023-24) and 9.91 (Pooled)] days to new growth, [31.11 (2022-23), 32.32 (2023-24) and 31.71 (Pooled)] days to runner formation after planting, [17.11 (2022-23), 17.79 (2023-24) and 17.45 (Pooled)] cm plant height, [17.62 (2022-23), 17.86 (2023-24) and 17.74 (Pooled)] number of leaves per plant, [66.21 (2022-23), 68.45 (2023-24) and 67.33 (Pooled)] cm2 leaf area, [5.27 (2022-23), 5.59 (2023-24) and 5.43 (Pooled)] number of runners per plant, [22.02 (2022-23), 22.33 (2023-24) and 22.19 (Pooled)] number of flower per plant, [71.13 (2022-23), 72.64 (2023-24) and 71.89 (Pooled)] % percentage of fruit setting (%) and [67.06 (2022-23), 69.07 (2023-24) and 68.07 (Pooled)] days taken to harvesting maturity.

Effect of Different Level of Nano Urea on Yield, Quality and Shelf life of Strawberry (Fragaria X ananassa) cv. Winter Dawn under Prayagraj Agro Climatic Condition, India

Nano fertilizers are the modern day concept of fertilizers and possess several benefits over conventional fertilizers. In very small quantity nano fertilizers have significant impact on the growth of crop. The present study consisted of 11 treatments utilising various combinations of conventional urea and nano urea, administered at varied doses and concentrations, with each treatment replicated three times in a Randomised Block Design. The main objective of the experiment was to assess the impact of varying concentrations of nano urea on the yield and quality characteristics along with shelf life of Strawberry (Fragaria X ananassa) cv. Winter Dawn. Treatment T7 [100% PK + 60% RDN + 0.8% Nano urea (8 ml/l)] was found best with [15.69 (2022-23), 16.23 (2023-24) and 15.96 (Pooled)] number of fruits per plant, [168.57 (2022-23), 177.28 (2023-24) and 172.92 (Pooled)] g yield per plant, [55.07 (2022-23), 57.92 (2023-24) and 56.49 (Pooled)] q/ha yield per hectare, ) [11.21 (2022-23), 11.54 (2023-24) and 11.38 (Pooled)] °Brix TSS, [0.60 (2022-23), 0.49 (2023-24) and 0.55 (Pooled)] % titrable acidity, [55.14 (2022-23), 56.86 (2023-24) and 56.00 (Pooled)] mg/100g ascorbic acid, [5.80 (2022-23), 6.00 (2023-24) and 5.90 (Pooled)] % total sugar, [4.17 (2022-23), 4.26 (2023-24) and 4.22 (Pooled)] % reducing sugar, [1.54 (2022-23), 1.65 (2023-24) and 1.60 (Pooled)] % non-reducing sugar and [4.34 (2022-23), 4.38 (2023-24) and 4.36 (Pooled)] days shelf life.

Nano urea’s environmental edge and economic efficacy in boosting wheat grain yield across diverse Indian agro-climates

The gradual increase in the consumption of mineral nitrogen is leading to heightened levels of harmful air pollutants, particularly N2O emissions from the agriculture sector. A potential solution to address the issues arising from the excessive use of urea in wheat is the substitution of conventional urea with nano urea. This study aimed to quantify the effects of nano urea, both independently and in conjunction with prilled urea, under various agroclimatic and sowing conditions in India. To achieve this objective, a multi-location field experiment on nano and prilled urea was conducted under irrigated conditions across 21 locations with 13 different treatments during the agricultural seasons of 2021–2022 and 2022–2023. The experiments followed a randomized block design with three replications, covering diverse agro-climatic regions of India. Analysis of combined data from multiple years and locations revealed that applying the recommended dose of nitrogen (RDN), i.e., 150 kg/ha in NWPZ (North western plains zone) and NEPZ (North eastern plains zone), and 120 kg/ha in CZ (Central zone) and PZ (Peninsular zone), along with two sprays of nano urea, resulted in a significant increase in grain yield 7.6%, 8.0%, 5.5%, and 9.1% in NWPZ, NEPZ, CZ, and PZ, respectively, compared to RDN alone. Notably, using 75% RDN along with either two sprays of nano urea or 5% urea showed a non-significant (P ≥ 0.05) difference in grain yield compared to the full RDN. From the perspective of higher net benefits, the combination of RDN and two sprays of 5% urea emerged as the most favourable option. On the other hand, considering the higher marginal rate of return (MRR), the combination of 75% RDN and two sprays of 5% urea proved to be more advantageous for farmers across the zones. In conclusion, environmentally friendly practices such as two sprays of nano urea or 5% urea combined with 75% RDN present promising alternatives for Indian farmers seeking to enhance wheat grain yield. Thus, this practice can save 25% of nitrogen (1.02 billion kg) which can reduce 5.06 billion kg CO2 equivalent emissions annually over recommended practice and can play a significant role in achieving the goal of net zero emissions by 2070 in India.

Application of Urea Nanoparticles in Low‐Land Rice Fields to Boost Crop Production While Maintaining Soil Fertility and Rhizospheric Health

ABSTRACTNano‐fertilizers are becoming promising in developing novel fertilization strategies while reducing the requirements of traditional fertilizers. Nano‐fertilizers have high nutrient use efficiency (NUE) and are required in small doses as compared to bulk fertilizers. The use of nano fertilizers in conjunction with a reduced dose of traditional fertilizers improves nutrient availability to plants and minimizes leaching and environmental contamination. The impact of the application of such an integrated fertilization approach on the soil fertility and microbiological population also needs to be understood. The present study investigates the influence of seven field treatments, including biogenic urea nanoparticles, as a source of N nutrient developed by TERI (referred as Teri's nano urea [TNU]), with and without conventional urea in an integrated manner. These treatments include the following: (T1)—100% recommended dose of nitrogen (RDN), (T2)—TNU alone, (T3) 100% RDN combined with TNU, (T4)—TNU at 50% concentration alone, (T5)—75% RDN combined with TNU, (T6) 50% RDN combined with TNU, and (T7) 50% RDN alone. RDF for N, P, and K used in the experiment is 140 kg/ha of urea for nitrogen fertilizer, 60 kg/ha of phosphorus, and 70 kg/ha of potassium in accordance with the local agronomic guidelines. A variable amount of urea was applied in different treatments but the recommended dose of phosphorous and potash fertilizers was applied consistently across the treatments. In different treatments, urea nanoparticles were applied as a nitrogen source via root dipping and foliar spray. The study also incorporates the economics of using nanoparticles to supplement nitrogen in an additive manner along with non‐nano macronutrient sources. Further, the influence of this novel approach of fertilization was also evaluated on the native microorganism species found in the rice fields. The results for the evaluated growth parameters, yield parameters, microbial population of soil, plant uptake, and cost economics suggest that at least 25% of the conventional urea requirement can be substituted with urea nanoparticles without causing harm to the bacterial and mycological species found in the rice agricultural fields.

Controlled Nitrogen Release by Hydroxyapatite Nanomaterials in Leaves Enhances Plant Growth and Nitrogen Uptake.

Nitrogen fertilizer delivery inefficiencies limit crop productivity and contribute to environmental pollution. Herein, we developed Zn- and Fe-doped hydroxyapatite nanomaterials (ZnHAU, FeHAU) loaded with urea (∼26% N) through hydrogen bonding and metal-ligand interactions. The nanomaterials attach to the leaf epidermal cuticle and localize in the apoplast of leaf epidermal cells, triggering a slow N release at acidic conditions (pH 5.8) that promote wheat (Triticum aestivum) growth and increased N uptake compared to conventional urea fertilizers. ZnHAU and FeHAU exhibited prolonged N release compared to urea in model plant apoplast fluid pH in vitro (up to 2 days) and in leaf membranes in plants (up to 10 days) with a high N retention (32% to 53%) under simulated high rainfall events (50 mm). Foliar N delivery doses of up to 4% as ZnHAU and FeHAU did not induce toxicity in plant cells. The foliar-applied ZnHAU and FeHAU enhanced fresh and dry biomass by ∼214% and ∼161%, and N uptake by ∼108% compared to foliar-applied urea under low soil N conditions in greenhouse experiments. Controlled N release by leaf-attached nanomaterials improves N delivery and use efficiency in crop plants, creating nanofertilizers with reduced environmental impact.

Co‐Benefits of Yield and Nitrogen Use Efficiency Gains Through Combined Use of Controlled‐Release Urea and Conventional Urea in Rice

ABSTRACTCombined use of controlled‐release urea and conventional urea (CCU) is considered a practical strategy to simultaneously achieve the dual benefits of crop yield and nitrogen use efficiency (NUE). However, the overall impact of CCU on rice production is not well understood. A meta‐analysis was conducted to determine the effect of CCU on rice yield and NUE in China. The results revealed that CCU increased rice yield by 6.22% and NUE by 16.5% compared with conventional urea. Significant yield and NUE gains from CCU were evident only when the ratio of controlled‐release urea to total nitrogen input reached 0.6 or above. Rice yield and NUE were increased simultaneously at nitrogen rates ranging from 150 to 225 kg ha−1, with no significant improvement in grain yield and NUE with nitrogen supply beyond 290 and 327 kg ha−1, respectively. In addition, rice yield and NUE were significantly greater with split rather than single application of CCU. Also, rice yield and NUE were increased when mean annual temperature (MAT), mean annual precipitation (MAP) and soil available nitrogen (AN) were more than 10°C, 800 mm, and 50 mg kg−1, respectively. Soil pH and organic matter content were significant determinants of rice yield and NUE gains with CCU. Our findings clearly demonstrate that the combined use of controlled‐release urea and conventional urea will deliver significant gains in rice yield and NUE and that it should be proposed as an effective measure for sustainable rice production.

Physiological, biochemical and soil microbial responses of green gram (Vigna radiata L.) to foliar nutrition of nano- fertilizers

A field experiment was conducted at Tamil Nadu Agricultural University, Coimbatore, during the summer of 2024 to determine the physiological, biochemical, and microbial responses of green gram to foliar nutrition of nano-fertilizers. The experiment was carried out in black heavy clay soil (Vertisol). Treatments included recommended doses of fertilizer (RDF) at 100%, 75%, and 50%, each combined with two rounds of foliar sprays using nano urea and nano DAP (first spray and a second spray 15 days later), along with conventional urea and DAP sprays, and a TNAU Pulse Wonder spray. Ten treatments were tested, each replicated three times in a randomized block design (RBD). Physiological (chlorophyll content), biochemical (soluble proteins, nitrate reductase activity), and microbiological (nodule number, microbial population) parameters were recorded at critical growth stages. The combination of 100% RDF with two nano DAP sprays resulted in significantly higher total chlorophyll concentration (increases of 21.4%, 10.7%), soluble protein content (increases of 30.5%, 15.7%), and nitrate reductase activity (increases of 30.1%, 14.7%), with values at par with 75% RDF + nano DAP foliar sprays twice, as well as 100% RDF + TNAU Pulse Wonder in comparison to 100% RDF with conventional DAP sprays, respectively observed after 1st spray. Notably, the 50% RDF + nano DAP significantly increased nodule number and microbial population at critical stages. Overall, the data demonstrated that 75% RDF + foliar spray of nano DAP (twice) has improved physiological and biochemical changes in green gram plants, indicating a potential saving of phosphorus fertilizers by up to 25%. Physiological responses were more pronounced with nano DAP than conventional DAP, likely due to its rapid absorption, quick assimilation and improved use efficiency.

Innovative urea formation using microwave plasma-water interaction: a study on reactive species and plant growth

Abstract This study explores the production of urea using microwave (MW) plasma-water interaction with air, N₂, CO₂, and a N₂ + CO₂ gas mixture to generate plasma-activated water (PAW). After 180 seconds of plasma exposure, air plasma reduced the pH to 3.3 and increased the oxidizing potential by 127.1%, making the water acidic and oxidizing, while the N₂ + CO₂ plasma raised the pH to 10.1 and reduced the oxidizing potential by 33.8%, creating basic and reducing conditions. PAW from air plasma produced the highest NO₂⁻ (51 mg L⁻¹) and NO₃⁻ (295 mg L⁻¹) concentrations, while the N₂ + CO₂ mixture generated the most NH₄⁺ (2250 mg L⁻¹), and CO₂ plasma produced the most CO₃²⁻ ions. Notably, urea formation (plasma urea) was observed only with CO₂ and N₂ + CO₂ plasmas, attributed to the formation of stable compounds like NH₄⁺ and NH₂COO⁻. In this process, NH₄⁺ ions formed via the reaction between atomic nitrogen and water, and their subsequent reaction with NH₂COO⁻ ions in the aqueous phase led to urea synthesis. The N₂ + CO₂ plasma produced 2991% more urea than CO₂ plasma. Plasma urea enhanced seed germination and plant growth, increasing germination rates for carrots by 10.67% and coriander by 15.6%. Shoot lengths grew by 38.6% for carrots and 30.8% for coriander, while root lengths improved by 24.24% and 37.5%, respectively, compared to controls. This study highlights MW plasma-water interaction as a sustainable, energy-efficient alternative to conventional urea production, offering significant environmental benefits and improved agricultural performance.

EVALUATION OF POLYMER-COATED UREA TO REDUCE NITROGEN LOSSES IN SOIL AND ITS APPLICATION TO OKRA ABELMOSCHUS ESCULENTUS (L.) MOENCH

The application of fertilizer aims to maximize crop yields and provide essential nutrients to plants. Efficiency problems, decreased yields, and environmental impact can result from nitrogen loss by volatilization and leaching. The delayed release of nitrogen can be achieved by coating urea with biodegradable compounds. The influence of several polymer-coated urea formulations and standard urea on nitrogen availability to okra plants was investigated in this study using lab and pot assessments. Key parameters were determined using soil samples taken at a depth of 15 cm. In the lab incubation, control, conventional urea, starch polymer-coated urea, neem oil-coated urea, and acacia gum-coated urea treatments were examined over 35 days. Soil samples were collected and examined on particular days. Okra plants were grown up to the flag leaf stage in the pot experiment using the same treatments. Data analysis demonstrated higher ammonium-nitrate and nitrate nitrogen concentrations in soils treated with polymer-coated urea, with acacia gum-coated urea exhibiting the slowest release. As release rates varied over time, nitrogen levels increased. Polymer-coated urea reduced ammonium loss, increased nutrient absorption, and boosted plant growth when compared to conventional urea. Urea with acacia gum coating functioned remarkably well, leading to increased nitrogen absorption. In conclusion, biodegradable polymer-coated urea increases nitrogen usage efficiency, decreasing losses and enhancing plant development, particularly when combined with acacia gum-coated urea. The results have practical significance for agricultural sustainability and the preservation of the environment.

Strategic Switching from Conventional Urea to Nano-Urea for Sustaining the Rice-Wheat Cropping System.

In the face of declining crop yields, inefficient fertilizer usage, nutrient depletion, and limited water availability, the efficiency of conventional NPK fertilizers is a critical issue in India. The hypothesis of this study posits that nano-nitrogen could enhance growth and photosynthetic efficiency in crop plants compared to conventional fertilizers. For this, a randomized block design (RBD) field experiment was conducted with six treatments: no nitrogen (T1), 100% N through urea (T2), and varying levels of N replacement with nano-nitrogen (33%: T3; 50%: T4; 66%: T5; and 100%: T6). Morphological and physiological traits and yield attributes were measured at physiological maturity, and yield attributes were measured at harvest. Results showed that 33% nitrogen replacement with nano-nitrogen (T3) outperformed conventional urea (T2) in physiological traits and achieved higher grain yields (3789 kg/ha for rice and 4206 kg/ha for wheat) compared to T2 (3737 kg/ha for rice and 4183 kg/ha for wheat with 100% urea). Although T4 and T5 showed statistically similar yields, they were lower than T2 and T3 for rice, while 50%, 66%, and 100% replacements reduced wheat yield by 2.49%, 8.39%, and 41.26%, respectively, compared to T2. Key enzymes of N metabolism decreased with higher nano-nitrogen substitution. Maximum nitrogen availability was observed in T2 and T3. This study concludes that nano-nitrogen is an effective strategy to enhance growth, balancing productivity and environmental sustainability.

Evaluation of nano urea for the production, economics and greenhouse gases emission reduction in wheat crop

Urea is important source of nitrogen (N) in wheat which is now facing issues of decreasing use efficiency, higher energy inputs and green house gases (GHG) emissions. Nano urea (NU) is recommended at a lower dose for similar yields. In view of this, an experiment was conducted to evaluate the NU and 5% urea (5 U) spray with different levels of recommended dose of nitrogen (RDN). In 2021–22, all the treatments recorded statistically equivalent values for effective tillers; however, different levels of RDN with NU recorded significantly higher values in 2022–23. The grain yield was significantly higher for 75% RDN + NU, at par with 50% RDN + NU during 2021–22, whereas, it was highest with latter during 2022–23. Gross and net returns followed the similar trend during both years. B: C ratio recorded highest values with NU supplementing 25% and 50% of RDN during 2021–22 and 2022–23, respectively. Highest values for output and net output energy were recorded with 75% RDN + NU and 75% RDN + 5 U during first and second year of experimentation, respectively. Supplementing 25–50% RDN with two sprays of NU recorded equivalent reduction in GHG emission. Lodging was recorded only in second year of experimentation, and its score was highest with RDN (19.0), whereas, it was lowest with 50% RDN + NU (2.0). Thus, replacing 50% of conventional urea with two sprays of NU can be a promising strategy for improving wheat productivity, simultaneously reducing the energy inputs and greenhouse gases emission.

Evaluation of NUE and Rice (<i>Oryza sativa </i>L.) Performance Through Application of Urea Stable Fertilizer in Ethiopia

An experiment based on randomized complete block design was conducted at Fogera and Libokemkem districts from 2017-2019 growing season. Nitrogen is the most yield liming nutrient that can be highly soluble and lost through leaching, volatilization and denitrification. The experiment was conducted to determine the effects of urea stable and convectional urea on rice performance and productivity. The experiment was laid out in randomized complete block design with three replications. The treatments were different rate of urea stable and convectional urea applied at planting and in split: (Control, 69 kg N ha<sup>-1</sup> from urea stable applied once at planting, 69 kg N ha<sup>-1</sup> from urea stable in split application, 34.5 kg N ha<sup>-1</sup> from urea stable in split application and 34.5 kg N ha<sup>-1</sup> from urea stable in once applied, 103.5 kg N ha<sup>-1</sup> from urea stable applied once at planting, 103.5 kg N ha<sup>-1</sup> from urea in split application, 69 kg N ha<sup>-1</sup> from conventional urea in split application, 103.5 kg N ha<sup>-1</sup> from conventional urea in split application). The applications of urea stable and conventional urea were significantly improved growth yield and yield components of rice as compared to control. Mean grain yield and biomass yield of rice was significantly affected by nitrogen rate and increased with increasing of nitrogen rate applied from urea stable and conventional urea. Moreover, the highest grain and biomass yield 4.8 t and 10.6 t was recorded from application of the recommended N in urea stable form once at planting in fogera district. Whereas the minimum grain (1.9 t/ha) and biomass yield (4.7 t/ha) was recorded from the negative control. At Libokemkem district the highest grain and biomass yield 3.9 tones and 9.3 t/ha was recorded respectively. But statistically similar from application of 103.5 kg N ha<sup>-1</sup> applied in split in the form of conventional urea (+ve control). Therefore, there was no evidence in our research that supports the advantage of urea stable over the conventional urea. Hence it is concluded that the application N fertilizers sources from both of urea and urea-stable are equal result obtained in improving of rice productivity and nitrogen use efficiency.

Productivity and Nutrition of Conilon Coffee (Coffea canephora) in Response to Slow-Realease Fertilizers

ABSTRACT The low availability of phosphorus (P) and nitrogen (N) in the soil is a determining factor in coffee plant productivity. To increase productivity technologies in fertilizers have been developed to improve the use of P and N by plants. Thus, the objective of this work was to evaluate the productivity and nutrition of the conilon coffee tree from the application of phosphate and nitrogen slow-release fertilizers. The experiment was conduced in the field and followed a randomized block design, with three replications, in a 3 × 2 × 3 factorial scheme, with three phosphate fertilizers (conventional monoammonium phosphate – CONV; conventional monoammonium phosphate coated with polymer – POL; and monoammonium phosphate conventional pelletized with filter cake – ORG); two amounts of phosphate fertilizers (Q100 = 100% of the amount of phosphate fertilizer; Q150 = 150% of the amount of phosphate fertilizer); and two nitrogen fertilizers (conventional urea – UC and conventional polymer-coated urea – UP). The experiment was conducted during two coffee harvests (2017/2018 and 2018/2019). Slow-release phosphate fertilizers (POL + ORG), when compared to CONV, showed higher productivity of processed coffee beans, representing an increase in productivity of 6.79% (5067,6 kg ha−1) and 11.62% (6048 kg ha−1) in the 2017/2018 and 2018/2019 harvests, respectively. The application of slow-release phosphate fertilizers (POL + ORG), in relation to CONV, also resulted in higher foliar P contents in some phenological stages of the coffee tree.

Lignin-based controlled-release urea improves choy sum growth by regulating soil nitrogen nutrients and bacterial diversity.

Lignin, as one of the few renewable resources among aromatic compounds, exhibits significant potential for applications in the agricultural sector. Nonetheless, there has been relatively limited research on the effects of lignin-based controlled-release urea (LCRU) on soil nitrogen nutrition and bacterial diversity. In this paper, the impact of LCRU on the growth of choy sum was investigated through a two-season field experiment. The findings suggest that the plant height, stem diameter, SPAD value, and above-ground dry weight under LCRU application surpassed those with conventional urea (CU), increasing by 40.27%, 26.97%, 52.02%, and 38.62%, respectively. Furthermore, the condition that the urea content was reduced by 15% (LCRU15) caused improvements of 24.76%, 26.97%, 43.23%, and 30.86% in the respective variables. Additionally, compared with the CU, the contents of vitamin C, soluble sugar, and soluble protein in choy sum were increased by the LCRU and LCRU15 treatments, and yet no significant differences were observed between the LCRU and LCRU15 treatments. Notably, the nitrogen used efficiency of choy sum increased to 68.90% with the LCRU15 treatment, compared to 64.29% with the LCRU treatment. The levels of soil available nitrogen, NO3 --N, and NH4 +-N were augmented by the LCRU and LCRU15 treatments. Meanwhile, soil urease and nitrate reductase activities were increased by 22.4%-28.6% and 12.3%-14.5%, respectively. Moreover, soil high-throughput sequencing results illustrated that the LCRU15 treatment enhanced the diversity and abundance of bacteria, particularly the abundance of Actinobacteria, Firmicutes, and Cyanobacteria, which can accelerate the decomposition of organic matter. In short, LCRU improves choy sum yield by influencing soil properties, enzyme activity, and microbial communities. These findings are anticipated to offer practical value for the sustainable application of LCRU in agriculture.

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

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

Effect of a Slow-Release Urea Nanofertilizer on Soil Microflora and Yield of Direct Seeded Rice (Oryza sativa L.)

Nitrogen fertilizers have a significant impact on the growth of rice. The overuse and inappropriate application of nitrogen fertilizers have resulted in environmental pollution, in addition to subjecting both humans and livestock to negative health hazards. Finding a viable substitute for traditional nitrogen fertilizers is crucial and essential to help improve crop yield and minimize environmental damage. Nano-nitrogen fertilizers offer a possible alternative to traditional fertilizers due to a slow/controlled release of nitrogen. The present work aimed to study the effect of a slow-release urea nanofertilizer on soil ammonical (NH4-N) and nitrate-N (NO3-N) content, culturable soil microflora, and soil enzyme activities in three different soil samples procured from Ludhiana and Patiala districts through a soil column study. Seven treatments, including 0, 50 (75 kg/ha N), 75 (112.5 kg/ha N), and 100% (150 kg/ha N) of the recommended dose (RD) of conventional urea and nano-urea fertilizer were applied. The leachate samples collected from nano-urea treatment exhibited NH4-N for the first two weeks, followed by NO3-N appearance. The higher NH4-N and NO3-N contents in the leachate were recorded for light-textured soil as compared to medium- and heavy-textured soil samples. The soil microbial counts and enzyme activities were recorded to be maximum in light-textured soils. Therefore, this slow-release formulation could be more useful for light-textured soils to decrease applied N-fertilizer losses, as well as for improving the soil microbial viable cell counts and soil enzyme activities. The effect of urea nanofertilizer on the growth and yield of direct-seeded rice (Oryza sativa L.) was also evaluated under field conditions. Both studies were performed independently. Numerically, the highest shoot height, fresh and dry shoot weight, and significantly maximum total chlorophyll, carotenoid, and anthocyanins were recorded in the T2 (100% RDF through nano-urea) treatment. The yield-attributing traits, including the number of filled grains and thousand-grain weight, were also recorded to have increased in T2 treatment. A numerical increase in NPK for plant and grain of rice at 100% RDN through nano-urea was recorded. The soil application of the product exhibited no negative effect on the soil microbial viable cell count on different doses of nano-urea fertilizer. The soil nitrogen fixer viable counts were rather improved in nano-urea treatments. The results reflect that nano-urea fertilizer could be considered as a possible alternative to conventional fertilizer.

Effects of nano urea on Indian mustard (Brassica juncea) productivity and nutrient uptake in calcareous soils

The experiment was conducted during winter (rabi) seasons of 2021–22 and 2022–23 at ICAR-Directorate of Rapeseed Mustard Research, Bharatpur, Rajasthan to assess the effect of nano urea (NU) spray in conjunction with different rates of soil applied fertilizer (conventional urea) N on growth, yield, nutrient content and uptake of Indian mustard [Brassica juncea (L.) Czern. and Coss.] in a calcareous soil of arid and semi-arid region. The experiment was conducted in a randomized complete block design (RCBD) and replicated thrice The treatment combinations consisted of basal applications of fertilizers and foliar spray (FS) of nano urea (NU) either once 30 days after sowing (DAS) or twice 30 and 50–55 DAS. The field experiment comprised of 9 treatments, viz. Control; Recommended dose of fertilizer (RDF); RDN25 + NU-1FS; RDN25 + NU-2FS; RDN50 + NU-1FS; RDN50 + NU-2FS; RDN100 + NU-1FS; RDN75 + NU-1FS; and RDN75 + NU-2FS. Results revealed that treatment RDN100 + NU-1FS (single sprays of nano urea together with the 100% prescribed dose of N) produced the maximum values of 24.30 and 66.62 q/ha yield of seed and stover, respectively. However, RDN75 + NU-2FS produced statistically comparable yield to the treatment RDN100 + NU-1FS. By applying nano urea, the recommended N dose can be reduced up to 25% without compromising yield. One FS of NU with RDN100 registered highest plant height, main shoot length, main shoot siliquae number, total siliquae number/plant and the number of secondary branches of the plant, and proved superior over other treatments. Further, results exhibited that RDN100 + NU-1FS increased N, P, and K uptake values to 66.74, 10.42, and 17.85 kg/ha in seed and 44.23, 9.48, and 78.98 kg/ha in stover. Overall, it has been determined that the most efficient way to increase the yield, concentration, and uptake of N, P, and K in Indian mustard is to apply nano urea foliar at 30 and 60 DAS in conjunction with RDF.

Efficiency of nitrogen fertilizers in newly implanted coffee crops

A vigorous and productive coffee crop is the result of adequate nutritional management from its young stage. High yields demand greater investments, especially in fertilization, making nutritional management indispensable. Hence, this study evaluated the growth of coffee crop formation, soil acidity and economic aspects using different fertilizers. The experiment was conducted at Pedra Bela site, Ouro Fino, Brazil, between November 2022 and June 2023. Experimental design consisted of randomized blocks with nine treatments and four replications, totaling 36 plots. Treatments included conventional urea, conventional urea via drench, ammonium nitrate, ammonium sulfate, urea + S0 + polymers, urea + NBPT, urea formaldehyde, organomineral CPMULT and coffee straw. Plant height, stem diameter, number of plagiotropic branches, defoliation percentage, soil pH, and costs were the variables evaluated. Treatment with ammonium nitrate achieved superior results in terms of pH growth within the range considered ideal for coffee crops compared with the other treatments. It also resulted in the highest number of plagiotropic branches, less defoliation and was the most cost-effective. As for soil acidity, ammonium nitrate and organomineral fertilizers promoted values within what is considered ideal for coffee cultivation.

Synthesis and Evaluation of Starch-Grafted-Poly[(Acrylic Acid)-Co-Acrylamide] Based Nanoclay Polymer Composite Fertilizers for Slow Release of Nitrogen in Soil.

Nitrogen (N) losses from conventional N fertilizers contribute to environmental degradation and low N use efficiency. Highlighting the need for slow-release fertilizers (SRFs) to mitigate these problems, this study aims to develop slow-release N fertilizers using starch-grafted-poly[(acrylic acid)-co-acrylamide] based nanoclay polymer composites (NCPCs) and investigate their efficacy for slow N delivery in soil. Three types of NCPCs, NCPC(A) (poly [(acrylic acid)-co-acrylamide]), NCPC(W) (wheat starch-grafted-poly[(acrylic acid)-co-acrylamide), and NCPC(M) (maize starch-grafted-poly[(acrylic acid)-co-acrylamide) were prepared and characterized using FTIR spectroscopy and X-ray diffraction techniques. N-release behaviour of the products was assessed under two distinct soils, i.e., Assam (Typic Hapludults, pH 4.2) and Delhi (Typic Haplustepts, pH 7.9) soils. Additionally, the effects of varying soil moisture and temperature levels on N release were studied in the Assam soil. The N-release kinetics of the synthesized fertilizers were assessed using zero-order, first-order, Higuchi, and Korsmeyer-Peppas models. Degradability of the NCPCs was evaluated by measuring evolved CO2-C under various soil conditions as an indicator of microbial degradation. The results indicated that NCPC fertilizers significantly slowed down the release of N compared to urea. According to the R2 values obtained, it was evident that the first-order kinetic model most accurately describes the N release from both urea and NCPC-based N fertilizers in the studied soils. Among the formulations, NCPC(A) exhibited the lowest N release (42.94-53.76%), followed by NCPC(M) (51.05-61.70%), NCPC(W) (54.86-67.75%), and urea (74.33-84.27%) after 21 days of incubation. The rate of N release was lower in the Assam soil compared to the Delhi soil, with higher soil moisture and temperature levels accelerating the release. Starch addition improved the biodegradability of the NCPCs, with NCPC(W) showing the highest cumulative CO2-C evolution (18.18-22.62 mg g-1), followed by NCPC(M) (15.54-20.97 mg g-1) and NCPC(A) (10.89-19.53 mg g-1). In conclusion, NCPC-based slow-release fertilizers demonstrated a more gradual N release compared to conventional urea and the inclusion of starch enhanced their degradability in the soil, which confirms their potential for sustainable agricultural applications. However, soil properties and environmental factors influenced the N release and degradation rates of NCPCs.