K.A. Gopinath

Optimization of Farmyard Manure to Substitute Mineral Fertilizer for Sustainable Productivity and Higher Carbon Sequestration Potential and Profitability under Gardenpea-French Bean Cropping System in the Indian Himalayas

Carbon sequestration potential (CSP) and sustainability of gardenpea-french bean cropping system was assessed with farmyard manure (FYM) application vis-à-vis mineral fertilization as recommended NPK (NPK) and integrated nutrient management practices (INM) after six years’ cropping in Indian Himalayas. Application of 20 tons FYM ha−1 provided highest CSP (0.527 Mg C ha−1 year−1) in soil and sustainability index. With the help of quadratic equations, it was estimated that maximum profit (optimum yield) and turn over of invested money could be achieved with application of 20.0 and 15.6 t FYM ha−1, respectively. Application of 5.9 and 8.9 tons FYM ha−1 would substitute NPK and INM, respectively. Pod number plant−1 was the most important yield-contributing attribute as found from principal component analysis. Pod yield could be modelled through multiple linear equation with help of yield attributes.

Application of Microbiology in Dryland Agriculture

Microorganisms are key players in nutrient cycling and hence form important components of a soil ecosystem. Besides, improving nutrient availability, certain microorganisms also provide growth and health benefits to plants through direct and indirect mechanisms. Dryland soils are are poorly developed with low organic matter content and hence have poor water retention capacity. Besides, dryland soils face various abiotic stresses like nutrient imbalance, drought, heat etc. Application of organic based fertilizers improves the microbial populations and soil organic carbon. Cropping systems and residue management practices also influence microbial parameters in dryland soils. Increased abundance of microorganisms in dryland soil can help in improving soil aggregation and soil organic matter carbon content, thus increasing the water retention capacity of the soil. Besides, microbial inoculants with specific function such as nutrient solubilization and mobilization, plant growth promotion, disease control and abiotic stress management can be applied alone or in combination. Thus, the promotion of microbial-based technologies and/or the management practices that improve soil microbial parameters is important for the sustainability of dryland ecosystems.

Dryland Agriculture in South Asia: Experiences, Challenges and Opportunities

South Asia, comprising Afghanistan, Bangladesh, Bhutan, India, the Maldives, Nepal, Pakistan and Sri Lanka, is the most densely populated geographical region in the world and is home to more than one-fifth of the world’s population. Most of the land (about three-fifths of the cropped area) in these countries is rainfed, which means that the economy of South Asia hinges on the annual success of their monsoons. The biggest challenges for dryland agriculture in the region are the declining natural resource base, climate change, and food and nutritional insecurity. The management of natural resources in dryland areas is critical not only because the livelihoods of millions of rural poor are directly connected to these regions but also because these areas will continue to play a crucial role in determining food security for the growing population and in reducing poverty in the coming decades. New opportunities lie in the knowledge-based management of natural resources, agricultural intensification, and adaptations to climate change, technology sharing, institutional innovations and improved intra-regional trade.

Irrigation Requirement of Crops under Changing Climatic Scenarios in a Semi-arid Region of Northern Karnataka

The groundwater status of Vijayapura district is under semi-critical to over-exploited category and optimal application of irrigation water is needed for the sustainable water management in this region. In the present study, the rainfall, temperature, evapotranspiration variability and irrigation requirement of major crops was analyzed for three future scenarios, namely, 2020’s (2010 to 2039), 2050’s (2040 to 2069) and 2080’s (2070 to 2099) with respect to the baseline period (1976-2005). The ENSEMBLE data corresponding to four different emission scenarios was used. Rainfall and temperature are important factors governing the irrigation requirement and the rainfall is predicted to increase from 590 mm during baseline period to 611, 646 and 677 mm under RCP 4.5 (medium emission scenario) and 617, 674 and 742 mm under high emission scenario (RCP 8.5). The maximum temperature is predicted to increase by 0.8, 1.6, 2.00C under RCP 4.5 and 0.9, 2.0, 3.60C under RCP 8.5. The minimum temperature is predicted to increase by 1.0, 1.8, 2.30C under RCP 4.5 and 1.1, 2.5, 4.20C under RCP 8.5 respectively. Correspondingly, the evapotranspiration values (ET0) are estimated to increase from 1851 to 1877, 1900 and 1916 mm under RCP 4.5 and 1876, 1912 and 1958 mm under RCP 8.5. The irrigation requirement of rabi sorghum is predicted to increase from 434 to 440, 447 and 449 mm under RCP 4.5 and 438, 445 and 453 mm under RCP 8.5. Similarly, the irrigation requirement of rabi maize is predicted to increase from 667 to 678, 688 and 694 mm under RCP 4.5 and 679, 694 and 712 mm under RCP 8.5, respectively. No considerable increase in the irrigation requirement for kharif crops was predicted in Vijayapura. In order to ensure long-term and sustainable groundwater utilization in the region, proper estimation of crop water requirement and its application are needed.

Climate Resilient Intercropping Systems for Rainfed Red Soils of Karnataka

In rainfed and dry regions of southern Karnataka, sole cropping is not much remunerative in the present scenario of climate change in agriculture to fulfill the diverse demands of consumers and burgeoning population. Hence, studies on intercropping systems were conducted in Alanatha cluster of villages in Ramanagara district and Chikkamaranahalli cluster in Bengaluru Rural district from 2010 to 2014 as a part of Operational Research Project (ORP) and National Innovations in Climate Resilient Agriculture (NICRA). In both the locations, finger millet (Eleusine coracana L.) + pigeonpea (Cajanus cajan L.) (8:2) with moisture conservation furrow between paired rows of pigeonpea intercropping recorded higher yield and economics as compared to the farmers’ practices of growing finger millet with akkadi crops. In groundnut (Arachis hypogaea L.) based cropping, groundnut+ pigeonpea (8:2) intercropping with moisture conservation furrow between paired rows of pigeonpea proved to be the better climate resilient intercropping system with higher yields in red soils of southern Karnataka. Under pulse based cropping systems, pigeonpea + cowpea (Vigna unguiculata L.) and pigeonpea + field bean (Phaseolus vulgaris L.) were remunerative when grown in additive series compared to sole crop of pigeonpea.