System of wheat intensification (SWI): Effects on lodging resistance, photosynthetic efficiency, soil biomes, and water productivity.

Intense cultivation with narrow row spacing in wheat, a common practice in the Indo-Gangetic plains of South Asia, renders the crop more susceptible to lodging during physiological maturity. This susceptibility, compounded by the use of traditional crop cultivars, has led to a substantial decline in overall crop productivity. In response to these challenges, a two-year field study on the system of wheat intensification (SWI) was conducted. The study involved three different cultivation methods in horizontal plots and four wheat genotypes in vertical plots, organized in a strip plot design. Our results exhibited that adoption of SWI at 20 cm × 20 cm resulted in significantly higher intercellular CO2 concentration (5.9-6.3%), transpiration rate (13.2-15.8%), stomatal conductance (55-59%), net photosynthetic rate (126-160%), and photosynthetically active radiation (PAR) interception (1.6-25.2%) over the existing conventional method (plant geometry 22.5 cm × continuous plant to plant spacing) of wheat cultivation. The lodging resistance capacity of both the lower and upper 3rd nodes was significantly higher in the SWI compared to other cultivation methods. Among different genotypes, HD 2967 demonstrated the highest recorded value for lodging resistance capacity, followed by HD 2851, HD 3086, and HD 2894. In addition, adoption of the SWI at 20 cm × 20 cm enhanced crop grain yield by 36.9-41.6%, and biological yield by 27.5-29.8%. Significantly higher soil dehydrogenase activity (12.06 µg TPF g-1 soil hr-1), arylsulfatase activity (82.8 µg p-nitro phenol g-1 soil hr-1), alkaline phosphatase activity (3.11 n moles ethylene g-1 soil hr-1), total polysaccharides, soil microbial biomass carbon, and soil chlorophyll content were also noted under SWI over conventional method of the production. Further, increased root volumes, surface root density and higher NPK uptake were recorded under SWI at 20×20 cm in comparison to rest of the treatments. Among the tested wheat genotypes, HD-2967 and HD-3086 had demonstrated notable increases in grain and biological yields, as well as improvements in the photosynthetically active radiation (PAR) and chlorophyll content. Therefore, adoption of SWI at 20 cm ×20 cm (square planting) with cultivars HD 2967 might be the best strategy for enhancing crop productivity and resource-use efficiency under the similar wheat growing conditions of India and similar agro-ecotypes of the globe.

Microbes-mediated integrated nutrient management for improved rhizo-modulation, pigeonpea productivity, and soil bio-fertility in a semi-arid agro-ecology.

Excessive dependence on chemical fertilizers and ignorance to organic and microbial inputs under intensive cropping systems are the basic components of contemporary agriculture, which evolves several sustainability issues, such as degraded soil health and sub-optimal crop productivity. This scenario urges for integrated nutrient management approaches, such as microbes-mediated integrated plant nutrition for curtailing the high doses as chemical fertilizers. Rationally, experiment has been conducted in pigeonpea at ICAR-IARI, New Delhi, with the aim of identifying the appropriate nutrient management technique involving microbial and organic nutrient sources for improved rhizo-modulation, crop productivity, and soil bio-fertility. The randomized block-designed experiment consisted nine treatments viz. Control, Recommended dose of fertilizers (RDF), RDF+ Microbial inoculants (MI), Vermicompost (VC), Farm Yard Manure (FYM), Leaf Compost (LC), VC + MI, FYM + MI, and LC + MI. Rhizobium spp., Pseudomonas spp., Bacillus spp., and Frateuria aurantia were used as seed-inoculating microbes. The results indicated the significant response of integration following the trend VC + MI > FYM + MI > LC + MI > RDF + MI for various plant shoot-root growth attributes and soil microbial and enzymatic properties. FYM + MI significantly improved the water-stable aggregates (22%), mean weight diameter (1.13 mm), and geometric mean diameter (0.93 mm), soil organic carbon (SOC), SOC stock, and SOC sequestration. The chemical properties viz. available N, P, and K were significantly improved with VC + MI. The study summarizes that FYM + MI could result in better soil physico-chemical and biological properties and shoot-root development; however; VC + MI could improve available nutrients in the soil and may enhance the growth of pigeonpea more effectively. The outcomes of the study are postulated as a viable and alternative solution for excessive chemical fertilizer-based nutrient management and would also promote the microbial consortia and organic manures-based agro-industries. This would add to the goal of sustainable agricultural development by producing quality crop produce, maintaining agro-biodiversity and making the soils fertile and healthy that would be a "gift to the society."

Crop and water productivity, energy auditing, carbon footprints and soil health indicators of Bt-cotton transplanting led system intensification.

Direct-seeded-cotton (DSC) leads to low crop and water productivity and energy-output with higher carbon-footprints besides impairing system-intensification under conventional cotton-wheat cropping system (CWCS). Hence, we evaluated two methods of Bt-cotton establishment [transplanted cotton (TPC) & DSC)] at three planting geometries/densities in four Bt-cotton based cropping-systems [DSC-wheat (DSC-W), TPC-wheat-mungbean (TPC-W-M), DSC-onion (DSC-O), TPC-onion-fodder cowpea + fodder maize (TPC-O-FC + FM)] in semi-arid region of south Asia. Poly-glass nursery-raised TPC exhibited significantly higher germination (96.5%), seedling-survival (96.1%) and 14.1% higher plant-stand owing to lower seedling-mortality (3.2%). TPC used ∼60% less irrigation-water but exhibited significantly higher seed-cotton, seed and lint yield, net-returns, radiation-use-efficiency and water-productivity by 11.4, 9.9, 14.3, 17.3, 10.7 and 260.6%, respectively over DSC. Planting geometry/density of 60 × 45 cm (37,037 plants ha-1) exhibited significantly higher crop and water productivity and economic-returns. Bt-cotton transplanting led system-intensification enhanced the system-productivity (26.1%), profitability (30.5%), water-productivity (19.3%) and land-use-efficiency (8.5%) over the DSC-based systems with significantly higher values under TPC-O-FC + FM. Energy-use pattern reveled that farm inputs viz. Fertilizers (54-60%), water (15-25%) and diesel (6-10%) consumed bulk of the input-energy in different cropping systems with greatest values under TPC-O-FC + FM. TPC-W-M exhibited highest system energy-output (604.6 × 103 MJ ha-1) and energy-returns (566.2 × 103 MJ ha-1). TPC-O-FC + FM exhibited significantly higher carbon-consumption (668.9 kg CE ha-1) and carbon-output (21431.3 kg CE ha-1) while maintaining significantly higher carbon-efficiency (32.0) and carbon sustainability index (31.0). TPC-O-FC + FM had least carbon-footprints (0.07 kg CE kg-1 SCEY) while conventional-CWCS exhibited 2-folds higher carbon-footprints. Legume-imbedded TPC-based cropping systems markedly increased the soil physical (bulk-density, water-stable-aggregates), chemical (SOC, available-NPK) and biological properties (soil-microbial-biomass-carbon, dehydrogenase and ergosterol activity) over the conventional CWCS and DCS-O systems. Overall, Bt-cotton transplanting led system-intensification upholds great importance in enhancing the system crop and water-productivity, profitability, energy-productivity, resource-use-efficiency and soil-health with minimal carbon-footprints in semi-arid agro-ecosystems of south Asia.