Farmers' Fertilizer Practice Research Articles

Conservation agriculture and nutrient management strategies for enhancing crop performance, productivity and nutrient uptake under rice-wheat cropping system

Understanding the relationship between tillage and nutrient management strategies is crucial for maintaining the long-term sustainability of the rice-wheat cropping system (RWCS). Therefore, a field experiment was conducted from 2022 to 2024 at Dr. Rajendra Prasad Central Agricultural University in Pusa, Samastipur, Bihar to study the effect of nutrient management strategies under conservation agriculture (CA) for enhancing crop growth performance, protein content and productivity of RWCS. The experiment was conducted in a split-plot design replicated thrice with 3 different tillage and crop establishment methods [zero tillage direct seeded rice (ZTDSR)-zero tillage wheat (ZTW), puddled DSR (PDSR)-ZT with rice residue retention (ZT + RR) and puddled transplanted rice (PTR)-conventional tillage wheat (CTW)] in main plots and four nutrient management strategies [Farmer’s Fertilizer Practices (FFP), Nutrient Expert recommended dose of fertilizer (NE-RDF), RDF + spray of nanourea (NU) and Customized fertilizer (CF)] in sub plots. In both years, crop growth attributes at harvest in rice were found maximum under PDSR while in wheat it was under ZT + RR. In wheat, ZT + RR recorded maximum grain yield which was 13 % and 14.5 % higher than CTW in 2022-23 and 2023-24 respectively. A decline in rice grain yield of 8.3 % and 8.9 % was recorded under FFP over NE-RDF in 2022 and 2023 respectively. Hence, PDSR followed by ZT+RR coupled with NE-RDF can increase agronomic performance and productivity under RWCS.

Reduced Fertilization and Magnesium Supplementation: Modulating Fruit Quality in Honey Pomelo (Citrus maxima (Burm.) Merr.)

The excessive use of chemical fertilizers in the Guanxi honey pomelo production area has led to severe soil acidification and magnesium (Mg) deficiency, adversely affecting pomelo fruit quality. To address this issue, an integrated nutrient optimization model crucial for ensuring the sustainable and environmentally friendly development of the Guanxi honey pomelo industry has been explored. In a three-year experiment, two fertilizer treatments were implemented: a farmer fertilizer practice (FP) and an NPK reduction plus foliar Mg fertilizer (OPT + fMg). We investigated the impact of this integrated optimized fertilization measure on pomelo fruit quality from three aspects: flavor (sugars and organic acids), nutrition (vitamin C and mineral elements), and antioxidant properties (phenolics, flavonoids, and phytic acid). The results revealed that the OPT + fMg treatment improved fruit flavor by reducing acidity (titratable acid, citric acid, and quinine), while having a minimal impact on sugar components (sucrose, fructose, and glucose). Additionally, the OPT + fMg treatment increased the total phenolics, total flavonoids, and phytic acid in the fruit peel, enhancing its potential antioxidant quality. However, the OPT + fMg treatment reduced the mineral nutrient quality (excluding calcium) in the fruit. As for the fruit developmental period, the OPT + fMg treatment significantly increased the total flavonoid concentration in the peel from the mid-expansion fruit stage, followed by notable increases in phytic acid in the peel during the mid-to-late expansion fruit stage. The total phenolic concentration in the peel significantly rose only during the late fruit development stage. The most pronounced effect was observed on phytic acid in both peel and pulp. The influence of the OPT + fMg treatment on the mineral nutrients (excluding calcium) primarily occurred during the mid-to-late expansion fruit stage. Overall, the OPT + fMg treatment significantly improved the comprehensive nutritional quality of pomelo fruit, providing valuable insights for scientifically reducing fertilizer application while enhancing fruit quality.

Analyzing Alternatives for Managing Nitrogen in Puddled Transplanted Rice in a Semi-Arid Area of India

The Bundelkhand region of India falls under a semi-arid climate and is not typical for rice cultivation. Rice cultivation has been expanding in heavy-textured soils with limited water irrigation. The experiment was carried out with a split-plot design with main factor transplanting methods (line and random transplanting) and subfactor six nitrogenmanagement options (omissionN (ON), farmers’fertilizer practice (FFP), state fertilizer recommendation (SFR), IRRI Leaf Color Chart (LCC), Panjab Agriculture University (PAU-LCC) and Rice Crop Manager (RCM) replicated thrice on heavy-textured soil at the student’s research farm, Banda University of Agriculture & Technology, Banda during the wet season of 2020 and 2021. IRRI LCC and PAU LCC also had significantly higher growth parameters and yield attributes for augmenting better farm livelihoods. The two-year average significant increases in grain yield of puddled transplanted rice by IRRI LLC (24.8% and 9.1%), PAU LCC (26.8% and 10.8%) and RCM (20.0% and 4.9%) over FFP and SFR, respectively. The two-year mean agronomic efficiency was found to be significantly better with IRRI LCC (57.5% and 39.6%), PAU LCC (52.1% and 34.8%) and RCM (57.6% and 39.7%) compared to FFP and SFR, respectively. Similarly, Kg N uptake Kg N applied−1 was significantly better with both the LCC and RCM-guided nitrogen application than FFP and SFR. Moreover, it was discovered that N management using SSNM choices reduced total GHG generation. According to our research, the farmers were applying nearly identical amounts of nitrogen, and SSNM tools allow for the efficient management of nitrogen in semi-arid regions by adjusting the timing of application and splitting.

Localized nitrogen supply facilitates rice yield and nitrogen use efficiency by enabling root-zone nitrogen distribution and root growth

IntroductionLocalized nitrogen (N) supply affects rice N uptake by influencing N release, and few studies have examined the effects of root zone N distribution and root growth on rice yield under localized N supply (LNS).MethodsA two-year field experiment was conducted with six treatments: no N application, farmers’ fertilizer practice (FFP), and four LNS treatments, including two types of N fertilizer with urea (U) and controlled release urea (CRU) were mechanically side deep fertilized (SDF) or root zone fertilized (RZF) at 10 cm soil depth (US, UR, CRUS and CRUR treatments, respectively).ResultsCompared with FFP, the dry matter accumulation, N uptake, and yield of LNS increased by 27%, 21%, and 17%, respectively. For N fertilizer type, compared with U, the NH4+-N concentration, total root surface area, volume, average diameter, and root biomass of CRU were significantly increased by 50%, 43%, 53%, and 23%, respectively, which resulted in a significant increase in yield by 12%. Regarding the N application methods, the total surface area, volume, average diameter, and root biomass of SDF were significantly increased by 32%, 24%, 10%, and 25% compared with RZF, respectively. However, the NH4+-N under RZF was more stable and lasted longer, with a significant increase in NH4+-N concentration of 21% compared to the SDF. Moreover, CRUR increased yield, N agronomic use efficiency, and gross return by 3.15%, 5.62%, and 2.81%, respectively, compared to CRUS.ConclusionCRU should be selected as the recommended N fertilizer types, and the combination of CRU and RZF was the most effective choice for rice production.

Digital technology in maize nutrient management research in northern Nigeria amid COVID-19 pandemic

The COVID-19 pandemic has been a life threatening and spreads wildly with physical human contact. Physical distancing is recommended by health experts to prevent the spread; thus, agronomic research has to be designed in conformity to this preventive standard during the pandemic. Consequently, this study was designed to evaluate the reliability of using digital tools in nutrient management research amid the COVID-19 pandemic in northern Nigeria. Fifty extension agents (EAs) were selected across 15 LGAs of Kaduna and Kano states. The EAs were trained on how to generate fertilizer recommendation using an android mobile phone-based nutrient expert (NE), to measure farmers’ field sizes using UTM Area measure mobile phone app, and open data kit to record, submit and aggregate data during the exercise. Each EA covered 50 farms, where two nutrient management practices—one determined by the farmers: farmer fertilizer practice (FFP), and the other generated using the NE were evaluated. Results show that around 90% of the farmers have an average field size of 1.13 ha. All selected farmers used improved maize varieties for planting, among which 21% been able to use the exact recommended or lower seed rate. Use of inorganic fertilizer was 33% higher than the average recommended NE rate, while average yield of the NE fields was 48% higher than for the FFP. The results of this study indicate that yield can be improved with site-specific nutrient management (SSNM) extension approach. The SSNM using digital tools as the NE seem promising and befits to agronomic research in northern Nigeria amid the COVID-19 pandemic.

Assessments of an Innovative Fertilizer Management Tool (Nutrient Expert®) for Improved Nutrient Management of Spring Maize at Rani Jamara Kulariya Irrigation Command Area of Tikapur, Kailali

A multi-locational field trials were assessed to know the innovative fertilizer management tool (Nutrient Expert®) for improved nutrient management of Spring Maize in Rani Jamara Kulariya Irrigation Project Command Area (RJKIPCA) of Tikapur, Kailali during spring season of 2021. The layout and planting of Spring Maize for NE® - Hybrid Maize model for 42 farmers’ fields (Tikapur-18, Janaki-18 and Lamkichuha-6)], and Nutrient Omission Plot Technique (NOPT) maize trials for 21 farmers’ fields (Tikapur-9, Janaki-9 and Lamkichuha-3) were grown using baby trail/ diamond trials in Randomized Complete Block Design (RCBD) considering farmers as replications. Data recording, tabulation, and analysis and interpretation of the data was performed by using ANOVA through the use of R Stat-software. Data analysis was also done for the yield gap analysis using percentage change in yield of Spring Maize over the location due to changes in crop cultivars and NOPT. The experimental results highlighted that most of the soils in the project site were deficit in N followed by K, with the minimum yield loss due to omission of P. The treatment; farmers' fertilizer practices (FFP) with their own cultivar has shown more decreasing trend in Spring Maize yields and it was more prominently seen within the farmers growing hybrid maize than the open pollinated variety (OPV). With huge percentage of yield gaps in Spring Maize denoted that the soil of Janaki and Tikapur were found to be more prone to N and K nutrients deficient than the soils of Lamkichuha. NE®- Hybrid Maize model has fairly predicted the Spring Maize yields and predicted the sound results on profitability with assured actual attainable yield over the FFP. Therefore, NE-model for Spring Maize is suggested to adopt as a recommended decision support system (DSS) tool in the project command areas of RJKIPCA, Tikapur, Kailali.

Effects of local nitrogen supply and nitrogen fertilizer variety coupling on rice nitrogen transport and soil nitrogen balance in paddy fields

IntroductionThis study aimed to provide the theoretical basis for formulating scientific and reasonable on-farm nitrogen (N) management measures and efficient strategic fertilization to understand the effects of localized N supply (LNS) and N fertilizer variety coupling on N transport and soil N balance in rice fields.MethodsA 2-year field experiment (2020 and 2021) was conducted in Jingzhou, Hubei Province, which included the following six treatments: no N application (CK), farmers' fertilizer practice (FFP), and four LNS treatments, including two N application methods including mechanical side-deep fertilization (M) and root-zone fertilization (R), two N fertilizer types with urea (U), and controlled-release urea (CRU).ResultsCompared with FFP, LNS increased the N apparent translocation level from stems, sheathes, and leaves (TNT) and N uptake by 10.70–50.59% and 11.28–29.71%, respectively. In LNS, the levels of nitrite reductase (NR), glutamine synthetase (GS), and glutamate synthase (GOGAT) under R increased by 13.81, 9.56, and 15.59%, respectively, compared with those under M, resulting in a significant increase in TNT by 8.58% and N uptake by 1.87%. Regarding the N fertilizer type, CRU significantly increased chlorophyll content by 7.27%, superoxide dismutase (SOD) and catalase (CAT) by 14.78 and 29.95% (p < 0.05), and NR, GS, and GOGAT by 44.41, 16.12, and 28.41% (p < 0.05), respectively, compared with that in U, which contributed to N absorption and transport. Moreover, CRUR significantly decreased N apparent loss by 50.04% compared with CRUM (p < 0.05).DiscussionConsidering the risk of soil N leaching and environmental protection, R should be selected as the recommended fertilization method. The combination of CRU and R is the most effective fertilization approach.

Failure to scale in digital agronomy: An analysis of site-specific nutrient management decision-support tools in developing countries

While many have extolled the potential impacts of digital advisory services for smallholder agriculture, the evidence for sustained uptake of such tools remains limited. This paper utilizes a survey of tool developers and researchers, as well as a systematic meta-analysis of prior studies, to assess the extent and challenges of scaling decision support tools for site-specific soil nutrient management (SSNM-DST) across smallholder farming systems, where “scaling” is defined as a significant increase in tool usage beyond pilot levels. Our evaluation draws on relevant literature, expert opinion and apps available in different repositories. Despite their acclaimed yield benefits, we find that SSNM-DST have struggled to reach scale over the last few decades and, with strong heterogeneity in adoption among intended stakeholders and tools. For example, the log odds of a SSNM-DST reaching 5–10 % of the target farmers compared with reaching none, decreases by ∼200% when a technical problem is stated as a reason for the tools’ failure to be used at scale. We find a similar decrease in odds ratios when technical, socioeconomic, policy, and R&D constraints were identified as barriers to scaling by national extension and private systems. Meta-regression analysis indicates that the response ratio of using SSNM-DST over Farmer Fertilizer Practice (FFP) varies by non-tool related covariates, such as initial crop yield potential under FFP, current and past crop types, acidity class of the soil, temperature and rainfall regimes, and the amount of input under FFP. In general, the SSNM-DST have moved one step forward compared with the traditional ‘blanket’ fertilizer recommendation by accounting for in-field heterogeneities in soil and crop characteristics, while remaining undifferentiated in terms of demographic and socioeconomic heterogeneities among users, which potentially constrains adoption at scale. The SSNM-DSTs possess reasonable applicability and can be labeled ‘ready’ from purely scientific viewpoints, although their readiness for system-level uptake at scale remains limited, especially where socio-technical and institutional constraints are prevalent.

Site-Specific Fertilizer Management through Nutrient Expert: Productivity, Profitability and Efficiency of Wheat

A field experiment was conducted at Tikapur, Kailali located in Sudur-Pashim Province of Nepal from November 2021 to April 2022 to determine the effects of site-specific nutrient management practice son the yield, economics and resource use efficiency of wheat (cv: Vijay). Six fertilizer treatments were laid-out in a Randomized Complete Block Design. The treatment includes nitrogen omitted plot (N0), blanket recommendation (BR), Nutrient Expert based-NPK (NE), Nutrient Expert based nitrogen recommendation and farmers fertilizer practice for other fertilizers (NE-N), leaf color chart-based nitrogen recommendation (LCC-N) and farmers fertilizer practice (FFP). NE produced the highest yield compared to BR and FFP. Grain yield between NE and LCC was similar (p>0.05). LCC-N produced the highest harvest index (0.46) and nitrogen use efficiency while they were the lowest in farmer-based practice. As with yield, NE produced higher gross revenue and benefit-cost ratio compared to farmers’ practice. Similarly, the maximum nitrogen uptake by grain and straw and soil residual N was observed in NE treated plot. These results suggested that NE based NPK management could increase yields, NUE and farm profit. However, similar benefits could also be achieved using either LCC based N management with 25 to 40% less N compared to NE. So, the fertilizer recommendation using NE-Wheat model in combination with LCC (if available to farmers) for N management could be suggested to the farmers for successful wheat cultivation.

Optimal phosphorus management strategies to enhance crop productivity and soil phosphorus fertility in rapeseed–rice rotation

Optimal phosphorus (P) managements can improve the crop yield without reducing soil P supply capacity over the long term. In this study, the rapeseed–rice rotation experiments were conducted to evaluate the effect of five optimal P fertilizer managements, including the addition of RA (rooting agents), PSB (phosphate solubilizing bacteria), CMP (calcium and magnesium phosphate fertilizer), DP1 (starter P) and DP2 (foliar fertilizer) with the reduction of 40% (in the 1st rapeseed season) and 75% (in the 2nd rapeseed season) P fertilizers of farmers’ fertilizer practice (FFP) on crop productivity and soil P fertility in low and high P fertility soils. Seed yield, P partial factor productivity, and P recovery efficiency of both cultivars, Shengguang168 (SG168) and Zhongshuang 11 (ZS11), were significantly improved under optimal P managements, and the increase of them in low P fertility soil was more than that in high P fertility soil. Total P surplus was lower under optimal P managements than under FFP in both P fertility soils. The increasing amount of crop yields under optimal P managements for both cultivars was equivalent to that of 16.0–38.3 kg P2O5 hm−2 of P fertilizer application, and the order of the optimal P managements was as follows: RA > PSB > CMP > DP1 > DP2. In addition, the grain yield of rotated rice cultivar Longliangyou1212 (LLY1212) without P supply was not reduced in both fertility soils. Compared with low P fertility soil, yields of SG168, ZS11 and LLY1212 in high P fertility soil increased by 28.1%–71.7%, 28.3%–78.9% and 26.2%–47.2% at the same treatment, respectively. In summary, optimal P managements in the rapeseed season could stabilize the crop yield, promote P use efficiency and the capacity of soil P supply in the rapeseed–rice rotation, especially in low P fertility soil.

Maize response to phosphorus and sulfur application on calcareous chernozem in Serbia

Field studies were conducted on carbonate chernozem in Vojvodina Province of Serbia during two seasons of maize growing to adjust nutrient management practices when fertilizers are broadcasted and incorporated into the soil before sowing. The experimental scheme included six fertilization treatments: T1 (zero fertilizer control), T2 (N156P64K64, farmer fertilizer practice), T3 (N100P60K60), T4 (N100P60K60S36), T5 (N100P80K60), and T6 (N100P80K60S48). Nitrogen application practice was found to be excessive, while phosphorus application practice was found to be insufficient. Phosphorus application rate of 80 kg P2O5 ha-1 was found to be rational when the soil test for phosphorus was very low or low. Sulfur (S) application improved grain yield in higher yield conditions, whereas soil containing 3.9–4.0% of organic matter (OM) could meet crop S requirements in lower yield conditions of 5 t ha-1 and below. It is assumed that S application to maize in the southern Pannonian Plain in Serbia may be limited to 36 kg S ha-1.

Site-specific Nutrient Management in Maize Tract of Khammam-based on STCR and Targeted Yield Approach

Soil variability is major factor behind the less yield, higher cost of cultivation and minimum profit. Geostatistics, principal component analysis and Fuzz C mean cluster algorithms are used to check soil spatial variability and help in reduction of spatial variability by diving field in to different management zone. Spatial variability of soil of Telangana was measured and also developed eight management zones for four ha using geostatistical analysis, Principal component analysis and Fuzz C mean cluster algorithm. Using above information, Field experiments were conducted at Khammam, Telanagana during rabi-2021 to demonstrate SSNM technique on farmer field using soil test crop response and targeted yield concept in maize crop. In this study, there are three treatments used: Treatment -1: - Fertilizer application based on eight soil sample testing, Treatment- 2: - Fertilizer application based on one soil sample testing, and Treatment -3: - Farmer fertilizer practices. The study concluded that grain yield over farmer fertilizer practices was highest in treatment -1 followed by treatment -2. Maximum gross return and gross return per ha over farmer fertilizer practice were observed in treatment -1 (Rs. 170170 and Rs. 26180.00 respectively) followed by treatment -2 (Rs. 157080 and Rs. 13090.00 respectively).

Effect of Integrated Nutrient Management on Performance of Chickpea in Bundelkhand Region of North India

A field experiment was carried out on chickpea crop during Rabi season 2020-21. The experiments were conducted on heavy clay soil at Agriculture Research Farm, College of Agriculture, Banda University of Agriculture & Technology, Banda. The experimental design was randomized block design with eight integrated nutrient management treatments viz. farmer fertilizer practice (T1), 100 % RDF (T2), 100% RDF + FYM (T3), 100 % RDF + FYM + Zn (10 kg ha-1) (T4), 125 % RDF + FYM+ microbial inoculants (MI) (T5), 100 % RDF + FYM+MI (T6), 75% RDF + FYM+MI (T7) and 50 % RDF +FYM+MI (T8), all treatments were replicated thrice. The FYM was applied @ 2 t acre-1. The experimental results revealed that application of 125% and 100 % RDF along with FYM and microbial inoculants increased significantly nodule number, nodule weight per plant and number of pods per plant, thereby increased grain yield of chickpea significantly in comparison to farmers fertilizer practice (T1), sole application of 100 % RDF (T2) and 50 % reduction of RDF along with FYM and microbial inoculants (T8).

Long-Term Conservation Tillage and Precision Nutrient Management in Maize–Wheat Cropping System: Effect on Soil Properties, Crop Production, and Economics

Intensive tillage coupled with imbalanced nutrient management in maize–wheat systems in low-carbon calcareous soils often results in poor productivity vis-à-vis degradation in soil health. Conservation tillage viz. permanent bed planting (PB) and zero tillage (ZT)/direct seeding with residue retention coupled with precision nutrient management might improve soil properties and yield of crops. Concerning this, a long-term experiment was conducted from 2014–2015 to 2020–2021 with a maize–wheat cropping system at TCA, Dholi farm of RPCAU, Pusa. Treatments consisted of three main plots of different tillage practices, viz. PB, ZT, and conventional tillage (CT) and three sub-plots of nutrient management options, viz. farmers’ fertilization practice (FFP), site-specific nutrient management with Nutrient Expert® (NE) software, and GreenSeeker (GS) based nitrogen-management. From this study, it was observed that both the PB and ZT resulted in about 31–33% and 43–45% improvement in SOC and water-soluble aggregates (WSA), respectively, comparing them under CT. These two conservation tillage practices also improved the other soil bio-chemical properties. Better soil properties under PB and ZT helped in the improvement of system yield by about 13–18% comparing yield under CT. Moreover, both these tillage practices showed an additional net return of USD 330–USD 400 over CT. PB was found a bit better over ZT concerning soil properties, yield, and economics. Comparing nutrient management options, precision nutrition using NE and GS showed significant improvement in the soil bio-chemical parameters, yield, and economics of the cropping system over FFP. SSNM using NE showed slightly better results than GS. Thus, from this long-term study, it can be concluded that the permanent bed system with residue retention and precision nutrition using Nutrient Expert® software are the best options concerning tillage and nutrient management, respectively, for improvement of the soil properties of problematic calcareous soils, thereby, enhancing the yield and economics of the maize–wheat cropping system.

Nitrogen optimization coupled with alternate wetting and drying practice enhances rhizospheric nitrifier and denitrifier abundance and rice productivity.

Optimizing nitrogen (N) fertilization without sacrificing grain yield is a major concern of rice production system because most of the applied N has been depleted from the soil and creating environmental consequences. Hence, limited information is available about nutrient management (NM) performance at a specific site under alternate wetting and drying (AWD) irrigation compared to conventional permanent flooding (PF). We aimed to inquire about the performance of NM practices compared to the farmer’s fertilizer practice (FFP) under PF and AWD on rhizospheric nitrifier and denitrifier abundance, rice yield, plant growth, and photosynthetic parameters. Two improved NM practices; nutrient management by pig manure (NMPM); 40% chemical N replaced by pig manure (organic N), and nutrient management by organic slow-release fertilizer (NMSR); 40% chemical N replaced by organic slow-release N were compared. The results showed an increased total grain yield (16.06%) during AWD compared to PF. Compared to conventional FFP, NMPM, and NMSR significantly increased the yields by 53.84 and 29.67%, respectively, during AWD. Meanwhile, PF prompted a yield increase of 45.07 and 28.75% for NMPM and NMSR, respectively, (p < 0.05) compared to FFP. Besides, a significant correlation was observed between grain yield and nitrogen content during AWD (R2 = 0.58, p < 0.01), but no significant correlation was observed during PF. The NMPM contributed to photosynthetic attributes and the relative chlorophyll content under both watering events. Moreover, relatively higher abundances of ammonia-oxidizing bacteria (AOB) and ammonia-oxidizing archaea (AOA) were observed during AWD, and the highest value was found after the late panicle stage. Our results suggest that the AWD–NMPM model is the best option to stimulate nitrifier and denitrifier gene abundance and promote rice production.

Hole fertilization in the root zone facilitates maize yield and nitrogen utilization by mitigating potential N loss and improving mineral N accumulation

Reducing environmental impacts and improving N utilization are critical to ensuring food security in China. Although root-zone fertilization has been considered an effective strategy to improve nitrogen use efficiency (NUE), the effect of controlled-release urea (CRU) applied in conjunction with normal urea in this mode is unclear. Therefore, a 3-year field experiment was conducted using a no-N-added as a control and two fertilization modes (FF, furrow fertilization by manual trenching, i.e., farmer fertilizer practice; HF: root-zone hole fertilization by point broadcast manually) at 210 kg N ha–1 (controlled-release:normal fertilizer=5:5), along with a 1-year in-situ microplot experiment. Maize yield, NUE and N loss were investigated under different fertilization modes. The results showed that compared with FF, HF improved the average yield and N recovery efficiency by 8.5 and 22.3% over three years, respectively. HF had a greater potential for application than FF treatment, which led to increases in dry matter accumulation, total N uptake, SPAD value and LAI. In addition, HF remarkably enhanced the accumulation of 15N derived from fertilizer by 17.2% compared with FF, which in turn reduced the potential loss of 15N by 43.8%. HF increased the accumulation of N in the tillage layer of soils at harvest for potential use in the subsequent season relative to FF. Hence, HF could match the N requirement of summer maize, sustain yield, improve NUE and reduce environmental N loss simultaneously. Overall, root-zone hole fertilization with blended CRU and normal urea can represent an effective and promising practice to achieve environmental integrity and food security on the North China Plain, which deserves further application and investigation.

Effect of GreenSeeker based nitrogen management and its interaction with water on growth and productivity of maize (Zea mays L.) under conservation agriculture

A field experiment was conducted during kharif season of 2019 at research farm of ICAR–Indian Agricultural Research Institute, New Delhi, India, to study the effect of GreenSeeker(GS) based nitrogen management and its interaction with water on growth and productivity of maize (Zea mays L.) var. PMH-1 under conservation agriculture. The experiment was laid out in split-split plot design withtwo crop establishment techniques (CET) viz. conservation agriculture (CA) and conventional tillage (CT) in main plots three irrigation regime (IR) in sub-plotsirrigation at critical growth stages, irrigation at 25% depletion of available soil moisture (DASM) and irrigation at 50% DASM, and four levels of nitrogen (N) in sub-sub plots; no-N applied, 33% N as basal, 33% N at knee high stage and 34% N at silking stage, 50% basal + rest N as guided by Green Seeker (GS) and 75% as basal + rest N as guided by GS. The results showed that GS based N application outperformed over farmers fertilizer practices in terms of growth and productivity, and its interactionalso significantly differed with irrigation scheduling. The maximum value of grain yield (6.9 tha-1 ), plant height at tasseling (173 cm) and harvest (235 cm), leaf area index at knee high stage (2.11) and silking (4.10), crop growth rate (8.4 and 9.2 gm-2 day-1 ) at 0-30 and 30-60 days after sowing, respectively and NDVI (0.748), were recorded under75% as basal + rest N as guided by GS, over other practices and interaction effect with irrigation at 25% depletion of available soil moisture.

Effect of GreenSeeker based nitrogen management and its interaction with water on growth and productivity of maize (Zea mays L.) under conservation agriculture

A field experiment was conducted during kharif season of 2019 at research farm of ICAR–Indian Agricultural Research Institute, New Delhi, India, to study the effect of GreenSeeker(GS) based nitrogen management and its interaction with water on growth and productivity of maize (Zea mays L.) var. PMH-1 under conservation agriculture. The experiment was laid out in split-split plot design withtwo crop establishment techniques (CET) viz. conservation agriculture (CA) and conventional tillage (CT) in main plots three irrigation regime (IR) in sub-plotsirrigation at critical growth stages, irrigation at 25% depletion of available soil moisture (DASM) and irrigation at 50% DASM, and four levels of nitrogen (N) in sub-sub plots; no-N applied, 33% N as basal, 33% N at knee high stage and 34% N at silking stage, 50% basal + rest N as guided by Green Seeker (GS) and 75% as basal + rest N as guided by GS. The results showed that GS based N application outperformed over farmers fertilizer practices in terms of growth and productivity, and its interactionalso significantly differed with irrigation scheduling. The maximum value of grain yield (6.9 tha-1), plant height at tasseling (173 cm) and harvest (235 cm), leaf area index at knee high stage (2.11) and silking (4.10), crop growth rate (8.4 and 9.2 gm-2day-1) at 0-30 and 30-60 days after sowing, respectively and NDVI (0.748), were recorded under75% as basal + rest N as guided by GS, over other practices and interaction effect with irrigation at 25% depletion of available soil moisture.

The source–sink balance during the grain filling period facilitates rice production under organic fertilizer substitution

Partial organic fertilizer substitution for chemical fertilizer has been proven to reduce the synthetic nitrogen (N) fertilizer requirement while maintaining or improving rice yield. However, little is known about the underlying physiological mechanisms of such an effect. Field trials were conducted to investigate the effect of organic fertilizer substitution for chemical fertilizer on rice yield and the source–sink relationship in two growing seasons. The treatments were as follows: no N fertilizer application (CK); farmers’ fertilizer practice (FFP); optimal chemical N management (OPT); and organic fertilizer substitution based on the OPT treatment (OPT-SN). Compared with treatments of chemical N fertilizer alone, rice yield was maintained in the OPT-SN treatment. The value of the sink–source difference in rice was positive during the grain filling period irrespective of the treatments, implying that the grain yield was source-limited. Although the effects on sink growth were similar among the different N addition treatments, organic fertilizer substitution improved source capacity by extending the duration of source activity when compared with treatments only containing chemical N fertilizer. The source–sink relationship was more balanced (lower sink–source difference) in the OPT-SN treatment relative to treatments of chemical N fertilizer alone, and a significant negative relationship between sink–source difference and grain yield was observed. Overall, organic fertilizer substitution could maintain grain yield by establishing a more balanced source–sink relationship during the grain filling period. Our findings clarify the positive effect of organic fertilizer substitution on source–sink balance and provide a basis for fertilization strategies to improve crop productivity.

Effect of nutrient management on yield, economics, water and energy use efficiency of maize (Zea mays) under conservation agriculture based maize-wheat (Triticum aestivum) system

A field experiment was conducted under long-term conservation agriculture (CA)-based maize (Zea mays L.)-wheat (Tricum aestivum L.)-mungbean (MWMb) system at ICAR- IARI, New Delhi (2017-18 and 2018-19) in split-plot design to compute the yields, economic, water and energy use-efficiency. There were 3-tillage treatment in main-plots and 4-nutrient management options in sub-plots with 3-replications. Results of present study showed that the grain yield of maize was 21.1% higher in CA-based permanent bed (PB) than conventional till (CT) plots. Net returns and net benefit cost ratio in PB plots was higher by 46.1 and 55.4% compared to CT, respectively (2-year mean basis). Two year mean basis water use-efficiency (WUE), net energy output and energy use-efficiency (EUE) were higher by 17.0, 26.3 and 12.5% in PB plots than CT. No significant effect of tillage was observed on N, P and K content (grains and stover). However, the total N, P and K uptake in maize grains and stover was higher by 23.6, 24.5 and 22.4% under PB than CT plots, respectively. Among nutrient management options; 2-year mean basis maize grain yield was 31.6 and 29.7% higher in Green Seeker (GS) guided-N and site specific nutrient management (SSNM) plots than farmers fertilizer practice (FFP), respectively. Net returns and BC ratio were also higher by 51.4-53.4% and 41.35-42.6% in GS guided-N and SSNM than FFP plots, respectively. WUE, net energy output and EUE were also significantly higher in GS guided-N treatment than FFP. Total N, P and K uptake were also significantly higher in GS guided-N and SSNM plots compared to FFP.