Soil enzymes-intricate molecular catalysts secreted by microorganisms, plant roots, and soil fauna play a central role in driving key biogeochemical processes that underpin soil health and fertility. As indispensable bioindicators, they are critical for the advancement of sustainable agriculture. This review examines the multifaceted roles of soil enzymes in nutrient cycling, organic matter decomposition, and the maintenance of soil structure, all of which enhance agroecosystem resilience and productivity. Key enzymes such as dehydrogenases, phosphatases, and beta-glucosidases facilitate the transformation of complex organic compounds into bioavailable nutrients, thereby improving nutrient-use efficiency and reducing dependence on synthetic fertilizers. Enzyme activity is highly sensitive to soil physicochemical conditions and management practices, offering valuable insights into the effects of conservation tillage, organic amendments, and crop rotation on soil health and biodiversity. Moreover, soil enzymes act as early indicators of environmental change, reflecting the influence of climatic variables, such as temperature and moisture, on soil functionality. Emerging technologies, including enzyme engineering and artificial intelligence-driven analytics, hold significant promise for optimizing nutrient availability, accelerating pollutant degradation, and enhancing crop resilience to biotic and abiotic stressors. Nonetheless, challenges remain, particularly in standardizing enzyme assays and in understanding the ecological implications of biotechnological interventions. Integrating molecular tools, such as metagenomics and transcriptomics, with practical soil management strategies is essential for harnessing enzymatic potential in building resilient and sustainable agroecosystems. Future research should focus on refining assay methodologies, validating predictive models under field conditions, and investigating enzyme responses to extreme weather events to fully unlock their potential for sustainable agriculture and environmental stewardship.

One of the major challenges in potato farming across the globe is potato cyst nematodes (PCN). Aeroponic root leachate (ARL),collected from aeroponically grown potato plants, was evaluated for its potential to stimulate Globodera rostochiensis hatching in the absence of a host plant. In vitro assays showed that ARL collected from 30-day-old potato plants induced the highest number of juveniles (J2s) hatching (369 J2s; 48%), far exceeding that induced by root exudate (RE) (105 J2s; 12.6%). Among the tested dilutions, ARL diluted to 50% was most effective (940 J2s; 74.5%), while controls showed no hatching. Pot assays revealed that ARL diluted to 50% and 75% reduced viable eggs by 28.9% and 27.8%, respectively, compared with minimal reductions in controls (tap water; 4.7% and nutrient solution; 6.2%). Field assays (2018-2021) confirmed strong declines in cyst counts across all treatments, with the greatest reduction observed in T3 (ARL diluted to 50%). Initial viable egg populations (235-287 per cyst) declined markedly by 2021, with T3 (ARL diluted to 50%) and T2 (ARL diluted to 75%) showing 46.5% and 44.1% reductions, compared with controls (13.1% in tap water and 11.2% in nutrient solution). In dose-response assays, ARL triggered higher hatching (284 J2s) than α-chaconine (228 J2s at 100 µg/ml) and α-solanine (186 J2s at 1 µg/ml). Further, ARL-assisted potato farming (ARL-APF) showed lower cultivation costs (643.4 USD/ha), energy inputs (34.5 GJ/ha), carbon inputs (1023.2 kg CE/ha), and GHG emissions (3745.9 CO2-e kg/ha) over the conventional potato farming (CPF).

Increasing environmental concerns associated with conventional irrigation and fertilization practices necessitate the development of sustainable crop management strategies in intensive systems such as the cotton–wheat rotation system (CWRS). This study evaluated the effects of sub-surface drip irrigation (SSDI), nitrogen fertigation levels, and foliar nutrition on productivity, resource-use efficiency, and environmental footprints. Results indicated that SSDI at 80% evapotranspiration (ETc) (I80) significantly improved system productivity (∼8.1%), benefit–cost ratio (∼5.1%) and energy productivity (∼4.3%) compared with 60% ETc (I60), while remaining statistically comparable to 100% ETc (I100). Optimized nitrogen fertigation (80% of recommended dose) sustained system productivity (8.51–8.64 t ha–1) while achieving ∼20% savings in nitrogen use and improving energy and carbon efficiency. Foliar nutrition (Mfoliar) further enhanced productivity and reduced carbon (∼4%) and water footprints (∼5.3%) compared to soil application. SSDI significantly reduced carbon footprints (upto ∼31%) compared to flood and surface drip systems, while irrigation at 80% ETc achieved net returns of ∼2718 $ ha–1, comparable to full irrigation, with ∼20% water savings. Overall, integrating SSDI at 80% ETc with optimized fertigation and foliar nutrition improved productivity and resource-use efficiency while reducing environmental footprints under the experimental conditions. These findings provide a sustainable strategy for improving cotton–wheat systems in similar agro-ecological regions.

Context: The maize-wheat (M-W) production system dominates semi-arid agroecosystem; however, maize productivity and nutrient-use efficiency (NUE) remain constrained under conventional tillage (CT) and suboptimal phosphorus (P) management. The combined influence of conservation agriculture (CA) and microbial-mediated P fertilization on crop performance and soil nutrient dynamics is not fully understood. Objective: This study evaluated the effect of tillage practices integrated with optimized P fertilization on maize productivity, resource-use efficiencies, soil P and carbon (C) fractions, and the carbon management index (CMI) within the M-W production system. Methods: A two-year field experiment (2016-2017) was conducted under semi-arid conditions using a split-plot design. Main plots included three tillage options: Conventional Tillage without residue (CT-R), Zero Tillage without residue (ZT-R), and Zero Tillage with residue (ZT+R). Sub-plots comprised five P-management practices (0-34.4 kg P ha(-)& sup1;), including a treatment combining reduced P input with phosphate-solubilizing bacteria (PSB). Results: ZT+R combined with the highest P rate (34.4 kg P ha(-)& sup1;) increased maize grain yield by similar to 57% and irrigation water productivity by similar to 49% compared with CT-R without P. Under ZT+R, grain protein yield increased by similar to 29% and nitrogen-phosphorus-potassium (NPK) uptake increased by similar to 31%, similar to 28%, and similar to 30%, respectively. The highest P rate enhanced protein yield by similar to 77% and nutrient uptake by similar to 72-76% relative to the no-P control. The combined application of reduced P (17.2 kg P ha(-)& sup1;) with PSB was associated with improvements in P recovery efficiency (similar to 65%) and agronomic efficiency (similar to 41%) compared to sole P application. ZT+R also increased labile and organic P fractions and improved soil C pools and CMI (similar to 3-10%) relative to CT-R and lower P inputs. Conclusions: Integrating CA practices, particularly ZT with residue retention, with optimized P fertilization improves maize productivity, resources-use efficiency, and soil P and C dynamics in semi-arid M-W systems. The inclusion of microbial-mediated P management showed beneficial associations with P-use efficiency; however, direct measurements of microbial activity and P transformation were not performed, and thus the underlying mechanisms should be interpreted with caution. Implications: These findings suggest that combining ZT+R with efficient P management strategies, including microbial inputs, can contribute to improved productivity and soil health. Further research incorporating biochemical and microbiological assessments is needed to validate the mechanistic role of microbial processes in enhancing phosphorus availability and system sustainability.

Global agriculture faces mounting pressure to sustain crop productivity while reducing dependence on synthetic inputs and minimising environmental harm. Brown manuring (BM) is a zero-tillage variant of green manuring in which a cover crop, grown alongside the main crop, is chemically desiccated at the flowering stage using a selective herbicide, typically 2,4-dichlorophenoxyacetic acid (2,4-D). Unlike conventional green manuring, BM does not require mechanical incorporation of plant material into the soil, thereby preserving soil structure and reducing labour costs. Upon desiccation, the standing biomass decomposes in situ, releasing N (up to 35–40 kg N ha−1 from leguminous species such as Sesbania spp. and Crotalaria juncea), P and K, while improving soil organic carbon content, microbial biomass, and water-holding capacity. BM has been shown to suppress weed populations by 40–94

Despite the proven advantages of Integrated nutrient management (INM) in enhancing soil fertility and crop yield, there remains a dearth of conspicuous focused research investigating its synergistic impact on comprehensive soil health in the acidic soils of Northeast India. This investigation elucidates the synergistic efficacy of INM protocols in leveraging cowpea (Vigna unguiculata) productivity, physiological performance, and soil health within the acidic Inceptisols of Northeast India to holistically address overall soil quality within challenging agroecosystems. Employing a randomized block design, six treatments were evaluated, with the most comprehensive protocol (treatment) (T6: 75

Micronutrient deficiencies are a major global-health challenge driven by inadequate dietary intake. Nutrient application to the soil for cereals like maize (Zea mays L.) offer a promising solution. Five combinations of Znembedded sulphur (Zn-ES) and multi-micronutrient embedded sulphur (MM-ES) with varied level of Recommended Doses of Fertilizers (RDF), two treatments of organic materials with 75 % RDF were evaluated relative to RDF and control. Multi-location trials were conducted in 2023 and 2024 at semi-arid ecologies of New Delhi and Karnal and temperate-highlands of Shimla. The mean maize grain yield was 5.65, 5.80 and 5.25 t ha-1 in New Delhi, Karnal and Shimla, respectively. The GGE biplot analysis revealed that application of Sulphur (S), Zn-ES and MM-ES with 100 % RDF (T6) resulted in highest yield at Karnal surpassing New Delhi (+4.9 %) and Shimla (+8.9 %) with greater stability at New Delhi in 2024 and Karnal in 2024. Furthermore, concentration of sulphur and micronutrients (Fe, Mn, Zn and Cu) were increased in T6 by 13-54.3 %. The remobilization efficiency of S (+22.6 %) and micronutrients (9.7-71.2 %) remained highest under T6 and T4, respectively. Harvest indices of S and micronutrients were improved by 10.4-89.3 % and 1.9-41 % relative to RDF. GGE biplot analysis in terms of micronutrient remobilization further exhibited consistency of T6. Highest soil microbial-biomass C (+6.92 %), acid phosphatase (+16.78 %), alkaline phosphatase (+6.77 %) and dehydrogenase (+35.2 %), were noted at Karnal under T6. The T6 enhanced RWC, SPAD and NDVI value by 6, 29.2 and 27.3 % and reduced proline content significantly. This study demonstrates that co-application of RDF with micronutrients optimizes maize productivity and biofortification, offering a sustainable strategy to address micronutrient malnutrition in line with 'One Health' framework.

Degradation of natural resources impairs environmental quality and sustainability of agricultural production systems. Conservation agriculture (CA) is a promising approach to ensure food security and agricultural sustainability. Likewise, plant nutrition especially phosphorus (P) optimization is highly essential for improved root architecture, cost-effectiveness and eco-friendliness under CA-management. Hence, current study assessed the influence of double zero-tilled bed-planting and optimized P-fertilization strategy on root architecture, carbon-phosphorus dynamics, and carbon management index in maize-wheat rotation (MWR) in south-Asian semi-arid agro-ecology. Results explained that CA based double zero-tilled permanent bed-planting (PRBZT) system harnessed higher root attributes over conventionally-tilled flat bed-planting (FBCT) system in MWR. Macro-aggregates, total water-stable aggregates, mean weight diameter and soil organic carbon under PRBZT system were 48.6, 11.5, 25 and 11.6 % higher over FBCT, respectively. PRBZT had ∼13.2-15.6 % enhanced soil phosphorus solubilizing bacteria, dehydrogenase enzyme activity, alkaline phosphatase activity, acid phosphatase activity and soil microbial biomass carbon over FBCT. In contrast, lability of soil organic carbon, pH, soil bulk density and micro-aggregates were found higher under FBCT. PRBZT plots had significantly higher soil carbon pools, carbon pool index, carbon management index, water-use efficiency over FBCT, partially addressing SDG-6 with enhanced water-use efficiency. The P-fertilization with P50+PSB + AMF+2FSP had 12.3, 57.2, 4.3 and 70.2 % higher available-NPK and phosphorus solubilizing bacteria over P0, respectively. The actual positive P-budgeting was revealed under CA, hence, addressing SDG-12. This study highlights that crop residue-retention @ 6 t ha-1year-1 under double zero-tilled permanent bed-planting (PRBZT) system combined with optimized phosphate fertilizer management is an effective agro-technology with fertilizer-P savings of ∼34.7 % and a positive phosphorus budget in MWR. This may ensure optimal nutrient P-availability, minimal P-loss, and stabilized soil P-fractions vis-à-vis significant positive influence on soil carbon fractions and carbon management index in MWR in resource-constrained semi-arid south-Asia. Overall, PRBZT system combined with optimized phosphate fertilizer management may be recommended for enhancing productivity, root architecture, resource-use efficiency, and soil carbon pools in south-Asian Indo-Gangetic Plain Region, which directly support several SDGs; SDG-2 (Zero-hunger), SDG-13 (Climate action) and SDG-15 (Life on land) thereby advancing ecosystem-resilience and productivity in the ensuing South-Asian climate crisis.

Amidst the current environmental challenges that exert immense pressure on the arable lands, adopting highly productive, eco-friendly conservation agriculture is crucial to feed the growing population. Low-cost approaches like residue-retention on permanent-beds with AM-fungi (AMF), can boost productivity, carbon-sequestration, and reduce energy and carbon footprints in water-scarce semi-arid areas. Current study quantified the crop and water productivity, energy and monetary budgeting, carbon-footprints, and carbon-sequestration of three planting-methods (PMs) and five Zn-fertilization practices (ZFPs) in pearl millet-wheat cropping system (PWCS). Results showed that BP + R + AMF (Bed-planting + residue-retention + AMF) registered 19.6, 15.4, 15.2, 20.6 and 16.3 % higher system-productivity, energy-output, carbon-output, SOC-stock, and net-returns in PWCS over FB-R (Flat-bed with no-residues), respectively. BP + R + AMF also registered significantly lower water-footprints by 21.2, 18.3 and 19.5 % in pearl millet, wheat, and PWCS over FB-R, respectively. Total CO2-e-emissions were higher (p < 0.05) under PMs, BP + R + AMF (4268.7 kg CO2-e ha-1) over FB-R (2905.5 kg CO2-e ha-1). Among ZFPs, Z4 (Soil + foliar applied Zn) had considerably higher system-productivity (17.7 %), bio-energy output (15.3 %), carbon-output (15.1 %) and net-returns (24.4 %) over no-Zn in PWCS. Overall, planting on permanent- beds with dual crop-basis residue-retention at 2.5 t ha-1 crop-1 coupled with AMF (BP + R + AMF) as well as combined Zn-fertilization may significantly enhance the system-productivity, net-returns, water-productivity, bioenergy-output, carbon-output, and carbon-stock in PWCS compared to FB-R and no-Zn. However, the farmers need to strike a balance while mulching crop-residues besides necessitating planting on raised-beds with AM-fungi and Zn-fertilization for clean, ecologically-friendly, and energy-efficient PWCS to ensure food security and mitigate climate-change in Zn-deficit semi-arid agro-ecologies.

Under climate-change, micro-irrigation practices like sub-surface drip-irrigation (SSDI) coupled with optimized-fertigation and foliar-nutrition, may improve crop-productivity and quality. Hence, current study in cotton (Gossypium hirsutum L.) comprised of three SSDI-regimes [60, 80, 100% ETc], two N-fertigation levels [80, 100% RDN] and two nutrient-application methods [foliar-spray of KNO3 & MgSO4 (Mfoliar) versus fertigation (Mfert)] in factorial randomized-complete-block-design besides three additional controls (surface-drip + N100 + Mfoliar; surface-drip + N100 + Mfert; flood-irrigation + soil RDN + Mfoliar). The results indicated that SSDI at 80%ETc enhanced seed-cotton-yield by ∼5.3 and 9.9%, ginning out-turn (GOT) by ∼2.1 and 4.8%, fiber-length by ∼5.7 and 7.6%, lint-index by ∼5.8 and 11% and protein-yield by ∼7.8 and 11.6%, over 60%ETc in 2019 and 2020. Oil-content, oil-yield, cake-content, and cake-yield varied significantly with increased irrigation from 60 to 100%ETc, underscoring the importance of adequate water for oil-synthesis in cottonseeds. Fatty-acid composition was sensitive to irrigation-levels, with significant reduction in saturated-fatty-acid (SFA) and unsaturated-fatty-acid (UFA) by ∼5.4 and 5.5%, and monounsaturated-fatty-acid (MUFA) and polyunsaturated-fatty-acid (PUFA) by ∼2.9 and 5.9% at 60%ETc over 80%ETc during 2019 and 2020, respectively. Polyunsaturated:saturated (P/S) index, vital for human cardio-vascular health, increased by ∼5.2 and 7.1% under 60%ETc. To harness higher yield with better quality fiber, protein, oil-yield and cottonseed-cake, SSDI at 80%ETc proved optimal, with no-additional benefits beyond this level. Enhancing fertigation from 80 to 100%RDN slightly enhanced UFAs and reduced SFAs. Higher UFAs is desirable for reducing low-density lipoprotein (LDL) cholesterol-levels. Foliar-spray of KNO3 & MgSO4 enhanced GOT, lint-index, UFAs, MUFA:PUFA and P/S index over fertigation. SSDI improved both fiber and seed-composition over flooding. Overall, SSDI at 80%ETc, combined with fertigation at 80%RDN and foliar-fertilization offers substantial benefits for cotton-productivity and quality in water-scarce agro-ecologies. These practices improve water-use-efficiency and sustainability, hence, enhancing resilience and economic-viability of cotton-industry amidst environmental-challenges.

Adopting sustainable agricultural practices that enhance productivity while preserving ecosystem services is essential to ensure food security for a growing global population and address environmental challenges. This review examines the impact of legume intercropping on nitrogen (N) fixation, soil physio-chemical properties, water retention, pest and disease control, and crop yield across diverse agro-climatic zones and cropping systems. The findings consistently demonstrate that integrating legumes into the cropping system improves soil health by reducing bulk density, breaking up hardpan layers, reducing erosion, increasing soil organic matter, and fixing atmospheric nitrogen (~125 kg N/ha/season) reducing the need for inorganic N fertilizers. It boosts crop yields by 30–35% (in terms of main crop equivalent yield) and land productivity per unit area and time, mitigates total crop loss, and promotes biodiversity. It also improves water use efficiency by 20–25% and enhances nutrient use efficiency by 25–30%. Additionally, legume intercropping reduces yield losses from pests and diseases by 20–25% compared to sole cropping systems. The practice bolsters crop resilience through ecological processes like bio-littering, bio-ploughing, bio-irrigation, and bio-pumping (the “4Bs”), which are valuable for adapting to climate variability. However, research gaps remain, particularly in the optimal selection of legume species for specific regions, suitable agronomic practice for each system, and addressing socio-economic barriers to widespread adoption.

ContextConventional tillage (CT), excessive irrigation, and indiscriminate nitrogen (N) use in wheat farming degrade soil and water resources in the Indo-Gangetic Plains (IGP), threatening the sustainability of the rice-wheat cropping system.ObjectivesA two-year study (2019–21) in north-west IGP was conducted to assess the integration of zero-tillage (ZT) with precision water and N management for sustainability, nutrient efficiency, and environmental performance.MethodsThe study tested two crop establishment methods (ZT-wheat and double ZT-wheat) and three irrigation regimes–25%, 50%, and 75% depletion of available soil moisture (DASM), with silicon applied at 75% DASM–alongside three N strategies: 100% recommended N dose (RDN), NutrientExpert® (NE®) + Leaf Color Chart (LCC), and NE® + SPAD-based N management, using a split-plot design.Results and ConclusionDouble ZT-wheat performed better over conventional ZT, showed superior growth (higher dry matter accumulation, leaf area index, and photosynthetic rate), 3.5% greater interception of photosynthetically active radiation (PAR), and 6.7–9.9% increases in grain/straw yields, and resource-use efficiency. Irrigation at 25% DASM increased photosynthetic activity, intercepted 18.3% more PAR, and yielded 9.23% higher grain over 50% DASM, though delaying irrigation to 50% DASM conserved water without significant yield loss. NE® + SPAD-based N management saved 40 kg N ha–1 while enhancing productivity and efficiency, and combining ZT with 75% DASM + silicon and NE® + LCC significantly reduced N2O emissions, thus suggested for implementation in the wheat growing regions.SignificanceThe current study findings promote precision N-water strategies, and double ZT to enhance productivity, resource conservation, and environmental sustainability in the IGP’s wheat systems addressing important sustainable development goals concerning agriculture.

Herbicide use may pose a risk of environmental pollution or evolution of resistant weeds. As a result, an experiment was carried out to assess the influence of different non-chemical weed management tactics (one hoeing (HH) at 12 DAS followed by (fb) one hand weeding at 30 DAS, one HH at 12 DAS fb Sesbania co-culture and its mulching, one HH at 12 DAS fb rice straw mulching @ 4t ha−1, one HH at 12 DAS fb rice straw mulching @ 6 t ha−1) on weed control, crop growth and yield, and economic returns in direct-seeded rice (DSR). Experiment was conducted during kharif season in a split-plot design and replicated thrice. Zero-till seed drill-sown crop (PN) had the lowest weed density at 25 days after sowing (DAS), while square planting geometry (PS) had the lowest weed density at 60 DAS. PS also resulted in a lower weed management index (WMI), agronomic management index (AMI), and integrated weed management index (IWMI), as well as higher growth attributes, grain yield (4.19 t ha–1), and net return (620.98 US$ ha–1). The cultivar Arize 6444 significantly reduced weed density and recorded higher growth attributes, yield, and economic return. In the case of weed management treatments, one HH at 12 DAS fb Sesbania co-culture and its mulching had the lowest weed density, Shannon-weinner index and eveness at 25 DAS. However, one hoeing at 12 DAS fb one hand weeding at 30 DAS (HH + WH) achieved the highest grain yield (4.85 t ha–1) and net returns (851.03 US$ ha–1) as well as the lowest weed density at 60 DAS. PS × HH + WH treatment combination had the lowest weed persistent index (WPI), WMI, AMI, and IWMI, and the highest growth attributes, production efficiency, and economic return.

Arbuscular mycorrhizal fungi (AMF) are symbiotic organisms that form intimate relationships with host plants by developing intracellular structures called arbuscules within root cortical cells. They are vital to natural ecosystems, offering a range of ecological benefits. They enhance the uptake and transfer of essential nutrients, influence the composition of fungal and bacterial communities in the soil, and improve soil texture and structure. They also strengthen plant resilience by mitigating the effects of salinity, drought, extreme temperatures, pathogens, pests, and weeds. They support plant defense mechanisms through the production of antimicrobial compounds, induction of defense-related biomolecules, and activation of resistance genes. This article provides a thorough review of recent research on the interactions between plant nutrients and AMF. It explores key mechanisms in nutrient uptake, and examines the morphological, biochemical, and molecular changes in plants colonized by AMF. Additionally, the article discusses AMF's crucial role in alleviating biotic stress. By shedding light on these aspects, the review identifies research gaps and suggests future directions. Harnessing AMF's potential can reduce dependence on agrochemicals and promote a more sustainable agricultural system.

A relative of cultivated rice (Oryza sativa L.), weedy or red rice (Oryza spp.) is currently recognized as the dominant weed, leading to a drastic loss of yield of cultivated rice due to its highly competitive abilities like producing more tillers, panicles, and biomass with better nutrient uptake. Due to its high nutritional value, antioxidant properties (anthocyanin and proanthocyanin), and nutrient absorption ability, weedy rice is gaining immense research attentions to understand its genetic constitution to augment future breeding strategies and to develop nutrition-rich functional foods. Consequently, this review focuses on the unique gene source of weedy rice to enhance the cultivated rice for its crucial features like water use efficiency, abiotic and biotic stress tolerance, early flowering, and the red pericarp of the seed. It explores the debating issues on the origin and evolution of weedy rice, including its high diversity, signalling aspects, quantitative trait loci (QTL) mapping under stress conditions, the intricacy of the mechanism in the expression of the gene flow, and ecological challenges of nutrient removal by weedy rice. This review may create a foundation for future researchers to understand the gene flow between cultivated crops and weedy traits and support an improved approach for the applicability of several models in predicting multiomics variables.

Indiscriminate use of chemicals in agriculture impacts soil properties, significantly compromising microbial diversity. Therefore, integrating eco-friendly strategies with minimal adverse impact on soil microflora and increasing crop productivity are essential for sustainable agriculture. The study was designed to understand the impact of different farming practices on the rhizospheric bacterial populations involved in nitrogen and phosphorus cycles, soil nutrient contents, and the uptake of nutrients by plants. A 3-year field experiment was set up in a randomized block pattern with pigeonpea-wheat cropping system (PWCS). Conventional and organic farming management practices were selected with two sets of organic amendments (ORG1: farmyard manure, ORG2: leaf compost + crop residue), three sets of conventional treatment [CON1: farmyard manure + 50% NPK (nitrogen, phosphorus, and potassium), CON2: leaf compost + crop residue + 50% NPK, and CON3: 100% NPK], and control (C). Plants and soil were sampled at the harvest stage of the crops for three consecutive cropping seasons to assess the soil and plant nutrient contents, and N and P cycling bacterial guilds in the rhizospheres. The total NPK uptake by plants was higher in conventional treatments than in organic treatments for both the crops, compared to the control treatment. Bacterial genes involved in the N and P cycles positively correlated with organic farming practice in both crops. Overall, agricultural management strategies had a significant impact on PWCS. The amoA gene was the most sensitive marker contributing to the variation in the abundance of the functional bacterial community in response to agri-management practices. Soil and plant NPK content showed a significant positive correlation in the case of the pigeonpea crop. The study showed the positive effect of different organic amendments on rhizospheric bacterial guilds. The combination of organic amendments with reduced chemical fertilizers intensifies the functioning of the N and P cycles. Organic amendments and reduced chemical fertilizers in PWCS offer a promising avenue for improving nutrient cycling, enhancing soil health, and ultimately bolstering crop productivity.

The current study identified two new climate-resilient groundnut-based cropping systems (GBCSs), viz., groundnut-fenugreek cropping system (GFCS) and groundnut-marigold cropping system (GMCS), with appropriate system-mode bio-compost embedded nutrient management schedules (SBINMSs) for semi-arid South Asia. This 5-year field study revealed that the GMCS along with leaf compost (LC) + 50% recommended dose of fertilizers (RDF50) in wet-season crop (groundnut) and 100% RDF (RDF100) in winter-season crop (marigold) exhibited the highest system productivity (5.13-5.99 t/ha), system profits (US$ 1,767-2,688/ha), and soil fertility (available NPK). Among SBINMSs, the application of 5 t/ha leaf and cow dung mixture compost (LCMC) with RDF50 showed the highest increase (0.41%) in soil organic carbon (SOC) followed by LC at 5 t/ha with RDF50 and RDF100. Legume-legume rotation (GFCS) had significantly higher soil microbial biomass carbon (SMBC) and soil microbial biomass nitrogen (SMBN) than legume-non-legume rotations (groundnut-wheat cropping system (GWCS) and GMCS). Among SBINMSs, the highest SMBC (201 µg/g dry soil) and SMBN (27.9 µg/g dry soil) were obtained when LCMC+RDF50 was applied to groundnut. The SMBC : SMBN ratio was the highest in the GWCS. LC+RDF50 exhibited the highest SMBC : SOC ratio (51.6). The largest increase in soil enzymatic activities was observed under LCMC+RDF50. Overall, the GMCS with LC+RDF50 in the wet season and RDF100 in the winter season proved highly productive and remunerative with better soil bio-fertility. SBINMSs saved chemical fertilizers by ~25%' in addition to enhanced system productivity and system profits across GBCSs in semi-arid regions of South Asia. Future research needs to focus on studying the potential of diversified production systems on water and environmental footprints, carbon dynamics, and energy productivity under semi-arid ecologies.

Weed control poses substantial difficulties for winter season onion (Allium cepa L.) cultivation in the north-western Indo-Gangetic Plains, primarily due to the constrained efficacy of the existing herbicides. To address this issue, a 2-year field study was conducted to assess the efficacy of pre- and post-emergence herbicides (pendimethalin, ethoxysulfuron, imazethapyr, and quizalofop-p-ethyl) individually and in combination with crop residue mulch for weed control in winter onion. The results revealed that using herbicides or mulches in isolation did not provide satisfactory weed control. However, the integration of natural mulch with pendimethalin followed by quizalofop-p-ethyl application proved to be the most effective weed control strategy, resulting in the least reduction in bulb yield (10.3%) compared to other treatments. On the contrary, combinations of pendimethalin with ethoxysulfuron or imazethapyr showed adverse effects on the onion crop and inflicted the highest yield losses among all treatments (78.6 and 83.4%, respectively). However, the combination of pendimethalin with quizalofop-p-ethyl coupled with crop mulch resulted in season-long weed control and over 80% bulb yield (36.58 t/ha) gains compared to the weed-free condition. These findings emphasize the efficacy of combining herbicides and mulches as an integrated weed management strategy for onions. By adopting such integrated approaches, farmers could improve weed control while maintaining bulb yield and quality, reducing the risks associated with herbicide resistance, and promoting sustainable onion production in the north-western Indo-Gangetic Plains.