Nitrogen Management Practices Research Articles

Effect of weed and nitrogen management practices on controlling weeds and enhancing the productivity of linseed (Linum usitatissimum L.) under utera conditions

Effect of weed and nitrogen management practices on controlling weeds and enhancing the productivity of linseed (Linum usitatissimum L.) under utera conditions

The Evaluation of a Novel Denitrifying Woodchip Bioreactor: Fairmont, MN, USA

The risk of nitrate contamination became a reality for Fairmont in Minnesota, when water rich in NO3-N exceeded the drinking water standard of 10 mg/L. This was unexpected because this city draws its municipal water from a chain of lakes that are fed primarily by shallow groundwater under row-crop land use. Spring soil thaw drives cold water into a subsurface pipe where almost no NO3-N reduction occurs. This paper focuses on NO3-N reduction before the water enters the lakes and no other nitrogen management practices in the watershed. A novel denitrifying bioreactor was constructed behind a sediment forebay, which then flowed into a chamber covered by a greenhouse before entering a woodchip bioreactor. In 2022 and 2023, water depth, dissolved oxygen, and temperature were measured at several locations in the bioreactor, and continuous NO3-N was measured at the entry and exit of the bioreactor. The results showed better performance at a low water depth with lower dissolved oxygen and higher water temperature. The greenhouse raised the inlet temperature in 2022 but did not in 2023. The forebay and the greenhouse may have impeded the denitrification process due to the high dissolved oxygen concentrations in the influent and the stratification of dissolved oxygen caused by algae in the bioreactor.

Conservation agriculture practices impact on biological and microbial diversity in earthworm cast under maize-wheat system

Soil degradation is a major global concern due to its negative impact on soil quality and the sustainability of agricultural resources. The conservation agriculture (CA) approach, which includes three key principles such as zero tillage, retention of crop residue and crop rotation has gained widespread adoption to help mitigate the climate change effects on agricultural soils and meet the growing demand for increased production. Earthworm communities, along with microbial activity and diversity, are highly sensitive to tillage practices. Additionally, microbial activity and diversity quickly respond to different cropping systems, making them effective indicators for detecting short-term changes in soil functioning. We therefore, assess the effects of CA innovative approached after 6-years on biological and microbial diversity within earthworm cast in maize-wheat system (MWS). The treatments consist of PBM-RN0/ZTW-RN0 (permanent beds No-N control-both residues removed and wheat with zero tillage); PBM+RN0/ZTW+RN0 (permanent beds No-N control-both residues retained)-50% of maize stover and 25% of wheat residue retained; PBM-RN120/ZTW- RN120 (permanent beds with 120 kg N ha-1 both residues removed wheat with zero tillage); PBM+RN120/ZTW+RN120 (permanent beds with 120 kg N ha-1 both residues retained and wheat with zero tillage) and FBM-RN120/CTW-RN120 (fresh beds in maize/CT in wheat with 120 kg N ha-1 both residues removed). The result of present study showed that activities of carbon (C) cycle-related enzymes in the cast soils viz., dehydrogenase (DHA), β-glucosidase (β-glu), cellulase, and xylanase were significantly higher under PBM+RN120/ ZTW+RN120 than under PBM-RN0/ZTW-RN0. Specifically, the activities of these enzymes were 21.5, 26.8, and 76.5% higher under the PBM+RN120/ZTW+RN120 treatment, respectively. Moreover, the Alk-P activity was found to be 1.3 times higher in the PBM+RN120/ZTW+RN120 treatment than in the PBM-RN0/ZTW-RN0 treatment. The bacterial, fungal, and actinomycete counts in the cast soil ranged from 6.87 to 7.47 CFU (colony forming units) x 106 g-1 soil, 3.87–3.30 CFU x 104 g-1 soil, and 5.09–5.67 CFU x 104 g-1 soil, respectively. Total organic carbon (TOC) showed significant increases of 34.6% under PBM+RN120/ZTW+RN120 as compared to PBM-RN0/ZTW-RN0. The less labile C (Frac. 3), total carbohydrate carbon (TCHO), phenol oxidase (PHE) and peroxidase (PER) were observed as the sensitive indicators under different tillage, rate of nitrogen and residue management practices. This study suggests that permanent beds with crop residue retention with balance fertilization practices can be recommended and popularized to the overall improvement of soil biological pools within earthworm casts in MWS.

Irrigation Scheduling and Nitrogen Management Practices Affected the Nutrient Concentration of Moth Bean under Arid Ecosystem

Efficient utilization of water and fertilizers is important for maximizing yield for moth bean production through improvement the nutrient use efficiency under arid ecosystem. The aim of this study was to evaluate the effects of irrigation and nitrogen fertilizers on growth, yield and nutrient content of moth bean in the western zone of Rajasthan during 2020 & 2021. Treatments included three levels of nitrogen (N1:15 kg N as basal + foliar spray of urea (2%) at flowering stage, N2: 15 kg N + foliar spray of urea (2%) at pod development stage and N3: 15 kg N + foliar spray of urea (2%) at flowering and pod development stages) and levels three levels of irrigation (I1: single irrigation at branching stage, I2: two irrigation at branching + pod development stages and I3: two irrigation at flowering + pod development stages) were laid down in factorial combinations of randomized block design with three replications. The results revealed that 15 kg N + foliar spray of urea (2%) at flowering and pod development stage recorded significantly higher nitrogen, phosphorus and potassium content in seed and haulm over 15 kg N + foliar spray of urea (2%) at flowering stage and 15 kg N + foliar spray of urea (2%) at pod development stage. However, the phosphorus content in seed and haulm was not significantly influenced by N3 and statistically equivalent with N2 and N1 during 2020 and 2021. Potassium content in seed showed significant enhancement under N3, while K content in haulm was not affected significantly during 2020 and pooled basis. Further, irrigation management practices did not show any significant improvement on N, P, K content in seed and haulm during years of 2020 and 2021. While, N content in seed and haulm was significantly improved under I2 over I3 and I1 on pooled basis. Thus, 15 kg N as basal application + foliar spray of urea (2%) at flowering and pod development stages with two irrigations at branching + pod development stages improved the nutrient content in moth bean in arid condition.

Effect of Tillage and Precision Nitrogen Management Practices on N Uptake and Nutrient Use Efficiency (NUE) in Wheat in Western Uttar Pradesh, India

At the Crop Research Center of Sardar Vallabhbhai Patel University of Agriculture & Technology, Meerut, (U.P.), during the rabi seasons of 2021–22 and 2022–23, an investigation titled " Effect of tillage and precision nitrogen management practices on N uptake and Nutrient Use Efficiency (NUE) in wheat in western UP " was conducted. The experiment was carried out using a split plot design with three replications. The treatments included four precise nitrogen treatments (N1-Control, N2-State recommendations, N3- Leaf Colour Chart (LCC) based nitrogen Application, and N4- Soil Plant Anaylsis Development (SPAD) meter based treatments) as sub plot treatments, and three conservation tillage treatments (C1- Conventional tillage, C2- Reduced tillage, and C3- Furrow irrigated raised bed (FIRB)} as main plots. The soil of the experimental site was sandy loam having low organic matter (0.43%), low in available nitrogen, low in available phosphorus and high in available potassium. The maximum N uptake and NUE was recorded under furrow irrigated raised beds plots during both the years. The maximum total N uptake and NUE was recorded under SPAD and was at par with LCC treatments.

Integrative knowledge-based nitrogen management practices can provide positive effects on ecosystem nitrogen retention.

Knowledge-based nitrogen (N) management provides better synchronization of crop N demand with N supply to enhance crop production while reducing N losses. Yet, how these N management practices contribute to reducing N losses globally is unclear. Here we compiled 5,448 paired observations from 336 publications representing 286 sites to assess the impacts of four common knowledge-based N management practices, including balanced fertilization, organic fertilization, co-application of synthetic and organic fertilizers, and nitrification inhibitors, on global ecosystem N cycling. We found that organic and balanced fertilization rather than N-only fertilization stimulated soil nitrate retention by enhancing microbial biomass, but also stimulated soil N leaching and emissions relative to no fertilizer addition. Nitrification inhibitors, however, stimulated soil ammonium retention and plant N uptake while reducing N leaching and emissions. Therefore, integrative application of knowledge-based N management practices is imperative to stimulate ecosystem N retention and minimize the risk of N loss globally.

Optimizing Water Use Efficiency and Yield of Wheat Crops through Integrated Irrigation and Nitrogen Management: A Comprehensive Review

Achieving sustainable agricultural productivity is critical due to the rising worldwide demand for food and the growing scarcity of water. This comprehensive review investigates the complex interrelations where integrated irrigation and nitrogen management are used as a strategic method to improve wheat crop yields and water use efficiency (WUE). The study synthesizes current research findings, methodologies, and technological advancements related to optimizing water and nitrogen inputs in wheat cultivation. A number of factors can affect WUE in wheat, including climate, soil, crop management practices, and genetic factors. There are a number of irrigation and nitrogen management practices that can be used to improve WUE in wheat, including deficit irrigation, mulching, and split applications of nitrogen fertilizer. The review underscores the significance of tailored irrigation and nitrogen management strategies in mitigating water stress, reducing nutrient runoff, and promoting sustainable agricultural practices. Insights from this comprehensive analysis aim to guide policymakers, agronomists, and farmers in making informed decisions for optimizing wheat production while conserving water resources and minimizing environmental impact. Future research on WUE can help to ensure that wheat production remains sustainable in the face of future challenges such as climate change and water scarcity.

Crop yield, water use efficiency and economic assessment of purple broccoli (Brassica oleracea) across varied water and nitrogen management practices

Inefficient management of irrigation and fertilizers emerges as the primary hurdle constraining the crop performance, profitability of broccoli (Brassica oleracea L. var. italica) production, resource wastage and environmental harm. To address this issue, a field experiment was conducted during winter (rabi) seasons of 2020–21 and 2021–22 at the research farm of ICAR-Indian Agricultural Research Institute, New Delhi. The research focused on investigating the effect of irrigation techniques and nitrogen management on broccoli yield, water use efficiency (WUE) and economic feasibility. The two main irrigation methods of drip irrigation and furrow irrigation as main factor, 2 irrigation regimes of full irrigation (100% ETC) and limited irrigation (75% ETC) as sub-factor, 3 nitrogen doses (N) of 125, 100 and 75% recommended dose of N as sub-sub factor were given and replicated thrice. The study aimed to analyse the yield, water use efficiency and assessment of economics under diverse irrigation water and N-management approaches. Under drip irrigation the mean yield and water-use efficiency shown substantial increase by 12 and 52% in comparison with furrow irrigated purple broccoli grown under the same condition. The highest benefit to cost (B:C) ratio of 3.81 and 4.79 was obtained in the treatment DRI1N1 during 2020–21 and 2021–22, respectively. Undoubtedly, the significance of adequate irrigation regime (100% ETC) and optimal N dose (125% RDN) became apparent, as they played significant roles in enhancing crop performance and ensuring the attainment of maximum broccoli yield, WUE and economics in Trans-Gangetic Plains region.

Yield and quality of dry direct-seeded rice (Oryza sativa) as influenced by nitrogen and weed management practices in Eastern India

Combined use of FYM and LCC based N management gave the highest grain yield, hulling, milling, head rice recovery, crude protein, protein yield (kg/ha) as well as highest nitrogen, phosphorus and potassium in grain and straw. In case of weed management practices, the sequential application of pendimethalin (1.5 kg/ha) as pre-emergence fb brown manuring with Sesbania aculeata (knocking down Sesbania by bispyribac-Na 25 g/ha at 25 DAS) resulted in better control of diverse weeds. It also proved to be the best treatment in terms of yield, physical and chemical grain quality parameters.

Ground Cover Rice Production System Affects Soil Water, Nitrogen Dynamics and Crop Growth Differentially with or without Climate Stress.

The ground cover rice production system (GCRPS) has been proposed as a potential solution to alleviate seasonal drought and early low-temperature stress in hilly mountainous areas; clarifying its impact on crop growth is crucial to enhance rice productivity in these areas. A two-year (2021-2022) field experiment was conducted in the hilly mountains of southwest China to compare the effects of the traditional flooding paddy (Paddy) and GCRPS under three different nitrogen (N) management practices (N1, zero-N fertilizer; N2, 135 kg N ha-1 as a urea-based fertilizer; and N3, 135 kg N ha-1 with a 3:2 base-topdressing ratio as urea fertilizer for the Paddy or a 1:1 basal application ratio as urea and manure for GCRPS) on soil water storage, soil mineral N content and crop growth parameters, including plant height, tiller numbers, the leaf area index (LAI), aboveground dry matter (DM) dynamics and crop yield. The results showed that there was a significant difference in rainfall between the two growth periods, with 906 mm and 291 mm in 2021 and 2022, respectively. While GCRPS did not significantly affect soil water storage, soil mineral N content, and plant height, it led to a reduction in partial tiller numbers (1.1% to 31.6%), LAI (0.6% to 20.4%), DM (4.4% to 18.8%), and crop yield (7.4% to 22.0%) in 2021 (wet year) compared to the Paddy. However, in 2022 (dry year), GCRPS led to an increase in tiller numbers (13.7% to 115.4%), LAI (17.3% to 81.0%), DM (9.0% to 62.6%), and crop yield (2.9% to 9.2%) compared to the Paddy. Structural equation modeling indicated that GCRPS significantly affected tiller numbers, plant height, LAI, DM, and productive tiller numbers, which indirectly influenced crop yield by significantly affecting tiller numbers and productive tiller numbers in 2022. Overall, the effects of GCRPS on soil water and N dynamics were not significant. In 2021, with high rainfall, no drought, and no early, low-temperature stress, the GCRPS suppressed crop growth and reduced yield, while in 2022, with drought and early low-temperature stress and low rainfall, the GCRPS promoted crop growth and increased yield, with tiller numbers and productive tiller numbers being the key factors affecting crop yield.

Evaluating Nitrogen Management Practices for Greenhouse Gas Emission Reduction in a Maize Farmland in the North China Plain: Adapting to Climate Change.

Quantification of the trade-offs among greenhouse gas (GHG) emissions, yield, and farmers' incomes is essential for proposing economic and environmental nitrogen (N) management strategies for optimizing agricultural production. A four-year (2017-2020) field experiment (including four treatments: basic N fertilizer treatment (BF), suitable utilization of fertilization (SU), emission reduction treatment (ER), and high fertilization (HF)) was conducted on maize (Zea mays L.) in the North China Plain. The Life Cycle Assessment (LCA) method was used in this study to quantify the GHG emissions and farmers' incomes during the whole maize production process. The total GHG emissions of BF, SU, ER, and HF treatments in the process of maize production are 10,755.2, 12,908.7, 11,950.1, and 14,274.5 kg CO2-eq ha-1, respectively, of which the direct emissions account for 84.8%, 76.8%, 74.9%, and 71.0%, respectively. Adding inhibitors significantly reduced direct GHG emissions, and the N2O and CO2 emissions from the maize fields in the ER treatment decreased by 30.0% and 7.9% compared to those in the SU treatment. Insignificant differences in yield were found between the SU and ER treatments, indicating that adding fertilizer inhibitors did not affect farmers' incomes while reducing GHG emissions. The yield for SU, ER, and HF treatments all significantly increased by 12.9-24.0%, 10.0-20.7%, and 2.1-17.4% compared to BF, respectively. In comparison with BF, both SU and ER significantly promoted agricultural net profit (ANP) by 16.6% and 12.2%, with mean ANP values of 3101.0 USD ha-1 and 2980.0 USD ha-1, respectively. Due to the high agricultural inputs, the ANP values in the HF treatment were 11.2%, 16.6%, and 12.4% lower than those in the SU treatment in 2018-2020. In conclusion, the combination of N fertilizer and inhibitors proved to be an environmentally friendly, high-profit, and low-emissions production technology while sustaining or even increasing maize yields in the North China Plain, which was conducive to achieving agricultural sustainability.

Better Inversion of Wheat Canopy SPAD Values before Heading Stage Using Spectral and Texture Indices Based on UAV Multispectral Imagery

In China’s second-largest wheat-producing region, the mid-lower Yangtze River area, cold stress impacts winter wheat production during the pre-heading growth stage. Previous research focused on specific growth stages, lacking a comprehensive approach. This study utilizes Unmanned Aerial Vehicle (UAV) multispectral imagery to monitor Soil-Plant Analysis Development (SPAD) values throughout the pre-heading stage, assessing crop stress resilience. Vegetation Indices (VIs) and Texture Indices (TIs) are extracted from UAV imagery. Recursive Feature Elimination (RFE) is applied to VIs, TIs, and fused variables (VIs + TIs), and six machine learning algorithms are employed for SPAD value estimation. The fused VIs and TIs model, based on Long Short-Term Memory (LSTM), achieves the highest accuracy (R2 = 0.8576, RMSE = 2.9352, RRMSE = 0.0644, RPD = 2.6677), demonstrating robust generalization across wheat varieties and nitrogen management practices. This research aids in mitigating winter wheat frost risks and increasing yields.

Irrigation Water and Nitrogen Fertilizer Management in Potato (Solanum tuberosum L.): A Review

Intensive irrigation and nutrient management practices in agriculture have given rise to serious issues in aquifer water depletion and groundwater quality. This review discusses the effects of irrigation and nitrogen management practices on potato growth, yield, and quality, and their impacts on water and nitrogen use efficiencies. This review also highlights the economics and consequences of applying deficit irrigation strategies in potato production. Many researchers have demonstrated that excessive irrigation and nitrogen application rates negatively impact potato tuber yield and quality while also increasing nitrate leaching, energy consumption, and the overall costs of production. An application of light-to-moderate deficit irrigation (10–30% of full irrigation) together with reduced nitrogen rates (60–170 kg/ha) has a great potential to improve water and nitrogen use efficiencies while obtaining optimum yield and quality in potato production, depending on the climate, variety, soil type, and water availability. There is an opportunity to reduce N application rates in potato production through deficit irrigation practices by minimizing nitrate leaching beyond the crop root zone. The best irrigation and nitrogen management techniques for potato production, as discussed in this review, include using sprinkle and drip irrigation techniques, irrigation scheduling based on local crop coefficients, soil moisture content, and crop modeling techniques, applying slow-release nitrogenous fertilizers, split nitrogen application, and applying water and nitrogenous fertilizers in accordance with crop growth stage requirements.

Managing nitrogen in maize production for societal gain.

Highly productive agriculture is essential to feed humanity, but agricultural practices often harm human health and the environment. Using a nitrogen (N) mass-balance model to account for N inputs and losses to the environment, along with empirical based models of yield response, we estimate the potential gains to society from improvements in nitrogen management that could reduce health and environmental costs from maize grown in the US Midwest. We find that the monetized health and environmental costs to society of current maize nitrogen management practices are six times larger than the profits earned by farmers. Air emissions of ammonia from application of synthetic fertilizer and manure are the largest source of pollution costs. We show that it is possible to reduce these costs by 85% ($21.6 billion per year, 2020$) while simultaneously increasing farmer profits. These gains come from (i) managing fertilizer ammonia emissions by changing the mix of fertilizer and manure applied, (ii) improving production efficiency by reducing fertilization rates, and (iii) halting maize production on land where health and environmental costs exceed farmer profits, namely on low-productivity land and locations in which emissions are especially harmful. Reducing ammonia emissions from changing fertilizer types-in (i)-reduces health and environmental costs by 46% ($11.7 billion). Reducing fertilization rates-in (ii)-limits nitrous oxide emissions, further reducing health and environmental costs by $9.5 billion, and halting production on 16% of maize-growing land in the Midwest-in (iii)-reduces costs by an additional $0.4 billion.

Impact of Tillage and Nitrogen Management Practices on Growth and Yield of Rabi Maize (Zea mays L.)

A field experiment was conducted in sandy loam soils of Agricultural Research Station, Karimnagar during Rabi, 2022 in a split-plot design with three replications. Main plots includes three tillage practices viz., Zero tillage, Reduced tillage and Conventional tillage and sub plots includes three nitrogen levels viz., 75 %N, 100%N and 125%N. The results revealed that, maize cultivation under conventional tillage recorded significantly higher grain yield (8324 kg ha-1) which is statistically on par with reduced tillage treatment (7775 kg ha-1). In turn reduced tillage was statistically comparable to zero-tillage treatment (7353kg ha-1). Among different nitrogen levels examined, maize sown with 125% N application achieved significantly highest grain yield (8055 kg ha-1). This yield was statistically comparable to grain yield observed with 100% N application (7896 kg ha-1). While, significantly lowest grain yield (7501 kg ha-1) was recorded with 75% N application. Significantly highest grain yield in conventional tillage which is statistically on par with reduced tillage and among nitrogen levels, highest grain yield with 125%N which is on par with 100% N may attributed to increase in crop growth parameters viz., plant height, leaf area index and higher yield attributes viz., cob length and diameter, kernel rows number. The study concludes that maize cultivation with conventional tillage or reduced tillage results in higher grain yield. Concerning different nitrogen levels, higher grain and economic yield was obtained with 100% N application.

A Review on Impact of Different Nitrogen Management Techniques on Maize (Zea mays L.) Crop Performance

Nitrogen (N), as a primary nutrient requirement of maize (Zea mays L.), plays a critical role in its development and productivity. Proper nitrogen management practices involve a delicate balance between providing an adequate amount of this nutrient and mitigating potential environmental impacts. When implemented effectively, these practices can significantly improve corn production. An adequate nitrogen supply promotes vigorous vegetative growth, contributing to strong stalks and an abundance of leaves, which are essential for maximizing the plant's photosynthetic capacity. This lush foliage, in turn, leads to increased photosynthesis and carbohydrate production, providing the energy maize needs throughout the reproductive stage to develop and fill its kernels. In addition, nitrogen is closely linked to kernel development. Well-timed and dosed nitrogen applications can result in larger, well-filled ears with plump kernels, ultimately increasing both the quantity and quality of the maize yield. Environmental considerations, such as reducing nitrogen runoff and greenhouse gas emissions, are important for maintaining ecosystems and mitigating climate change. Thus, this review article highlights the need for a holistic approach to nitrogen management, combining innovative techniques with sustainable agricultural practices, to ensure food security and environmental conservation in maize production systems.

Climate change impact on potato (Solanum tuberosum) productivity and relative adaptation strategies

WOFOST and InfoCrop crop growth simulation models were used to assess the impact of climate change on potato cultivars and to develop adaptation strategies for future climatic scenarios (2030, 2050 and 2080) under representative concentration pathways (RCP’s) 4.5 and 6.0 in Bihar. Potato cultivars belonging to late (Kufri Badshah), medium (Kufri Jyoti) and early (Kufri Pukhraj) maturity groups were selected. The simulated results revealed variations in potential productivity of potato under both RCP’s (4.5 & 6.0) with baseline yields of 43.80 t ha-1 for Kufri Badshah, 41.5 t ha-1 for Kufri Jyoti and 43.6 t ha-1 for Kufri Pukhraj. Under RCP 4.5, elevated concentration of CO2 projected to increase the productivity of Kufri Badshah, Kufri Jyoti, and Kufri Pukhraj. However, a decline in yield is expected when individual effect of temperature is considered for future climatic scenarios (2030, 2050 & 2080). However, these yield loss is negated when combined effect of CO2 and temperature is considered by 1.3, 0.7 and 0.3 % in 2030, by -0.4, -1.1 and -2.2 % in 2050 and by 3.5, 4.4 and 5.9 % in 2080, respectively. Likewise, for RCP 6.0, combined effect of CO2 and temperature offset the yield losses by 2.6, 2.4 and 2.3% in 2030, 2.1, 1.7 and 1.1 in 2050 and 1.1, -0.1 and -1.8 in 2080. In addition, selection of suitable cultivars, shifting the date of planting and proper irrigation and nitrogen management practices can counterbalance the yield losses.

The influences of graphene oxide and nitrification inhibitor on vegetable growths and soil and endophytic bacterial communities: Double-edge sword effects and nitrate risk controls

Crop yield and quality are substantial indicators of evaluating agricultural nitrogen management practices, and the nitrate (NO3−-N) is one of the predominant factors affecting crop quality. The NO3−-N accumulation in vegetable crop affects plant growth and quality and human health. Therefore, it is necessary to stimulate vegetable yield but eliminate excessive NO3−-N in soils and plants with feasible management strategies. Graphene oxide (GO) is a novel carbon nanomaterial that has attracted great attention, but rare research has been conducted to quantify the effects of GO on plant NO3−-N accumulation and microbial communities. This study explored effects of the GO and nitrification inhibitors, dicyandiamide (DCD) and 3, 4-dimethylpyrazole phosphate (DMPP), on vegetable yields and NO3−-N contents and bacterial communities in soil-cabbage (Brassica rapa subsp. Chinensis) system. The soil NO3−-N content was significantly reduced with the single GO application. The cabbage NO3−-N content was increased by 60.4 % while the cabbage yield was significantly enhanced by 101.9 % with the single GO application. Meanwhile, the Invsimpson index of soil bacterial community and the ACE and Chao1 richness estimators of endophytic bacterial community were significantly decreased by the GO application. Cabbage NO3−-N content was significantly and negatively correlated with the soil Myxococcota, endophytic bacterial community co-occurrence network edge, cabbage soluble sugar and cabbage proline. The GO application generated double-edged sword effects of positively promoting yield but causing risks of NO3−-N accumulation and quality deterioration. However, these adverse effects could be mitigated by the extra nitrification inhibitor application. The potential ecological risks of GO application to the vegetable quality and endophytic community should be considered.

Effect of Varying Levels and Source of Slow-release Urea Fertilizers on Yield, Post Harvest Soil Nutrient Status and Economics of Wet Direct Seeded Rice (Oryza sativa L.)

A field experiment was conducted at the research farm of ICAR-Indian Institute of Rice Research (IIRR), Hyderabad, Rajendranagar in kharif, 2022 to study the effect of varying levels and source of slow-release urea fertilizers on yield, post harvest soil nutrient status and economics of wet direct seeded rice. The experiment was laid out in a randomized block design with ten treatments consisting of nitrogen management practices and replicated thrice. The results revealed that 100% RDN (Recommended Dose of Nitrogen) (120 kg/ha) applied through silicon coated urea resulted in the highest grain yield (6249 kg/ha) and straw yield (7114 kg/ha). Post harvest soil nutrient status revealed that 125% recommended dose nitrogen (150 kg/ha) applied through silicon coated urea resulted in the highest soil available nitrogen. Similarly, the highest soil available nitrogen gain was recorded in the plots that received 125% silicon coated urea. Silicon coated urea applied @ 120 kg/ha ulimately fetched higher gross return of ₹. 1,42,964/ha, net returns ₹. 1,03,793 and benefit-cost ratio of 2.65. It can be concluded that RDN applied through silicon coated urea @ 120 kg/ha found to be a suitable alternative to neem coated urea in increasing the grain yield, soil fertility and profitability.

Cultivation and Nitrogen Management Practices Effect on Soil Carbon Fractions, Greenhouse Gas Emissions, and Maize Production under Dry-Land Farming System

Effective nitrogen management practices by using two cultivation techniques can improve corn productivity and soil carbon components such as soil carbon storage, microbial biomass carbon (MBC), carbon management index (CMI), and water-soluble carbon (WSC). It is essential to ensure the long-term protection of dry-land agricultural systems. However, excessive application of nitrogen fertilizer reduces the efficiency of nitrogen use and also leads to increased greenhouse gas emissions from farming soil and several other ecological problems. Therefore, we conducted field trials under two planting methods during 2019–2020: P: plastic mulching ridges; F: traditional flat planting with nitrogen management practices, i.e., 0: no nitrogen fertilizer; FN: a common nitrogen fertilizer rate for farmers of 290 kg ha−1; ON: optimal nitrogen application rate of 230 kg ha−1; ON75%+DCD: 25% reduction in optimal nitrogen fertilizer rate + dicyandiamide; ON75%+NC: 25% reduction in optimal nitrogen rate + nano-carbon. The results showed that compared to other treatments, the PON75%+DCD treatment significantly increased soil water storage, water use efficiency (WUE), and nitrogen use efficiency (NUE) because total evapotranspiration (ET) and GHG were reduced. Under the PON75%+DCD or PON75%+NC, the soil carbon storage significantly (50% or 47%) increased. The PON75%+DCD treatment is more effective in improving MBC, CMI, and WSC, although it increases gaseous carbon emissions more than all other treatments. Compared with FFN, under the PON75%+DCD treatment, the overall CH4, N2O, and CO2 emissions are all reduced. Under the PON75%+DCD treatment, the area scale GWP (52.7%), yield scale GWP (90.3%), biomass yield (22.7%), WUE (42.6%), NUE (80.0%), and grain yield (32.1%) significantly increased compared with FFN, which might offset the negative ecological impacts connected with climate change. The PON75%+DCD treatment can have obvious benefits in terms of increasing yield and reducing emissions. It can be recommended to ensure future food security and optimal planting and nitrogen management practices in response to climate change.