Browsing by Author "J.V.N.S. Prasad"

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Improving Water Storage through Effective Soil Organic Matter Management Strategies under Dryland Farming in India
(CRC Press, 2024) C. Srinivasarao; S. Rakesh; G.Ranjith Kumar; M. Jagadesh; K.C. Nataraj; R. Manasa; S. Kundu; S. Malleswari; K.V. Rao; J.V.N.S. Prasad; R.S. Meena; G. Venkatesh; P.C. Abhilash; J. Somasundaram; R. Lal
With the rise in global population, food demand is increasing particularly in densely populated South Asia. In India, rainfed area covers about 55% of the net sown area (139.42 million ha) and about 61% of the farmers are cultivating crops under the rainfed region. Almost 80% of small and marginal farmers of the country depend on the rainfed farming for their livelihoods. Rainfall is the main source of water in drylands. Coping with the extreme variability in rainfall, high-intensity storms, and high frequency of dry spells are the key challenges in rainfed agriculture as it is complex, highly diverse, and risk prone. Soil organic carbon (SOC) has a critical role in soil plant water relationships and contributes to drought mitigation. Increasing SOC by 1% may increase the available water holding capacity (AWHC) by 2 to >5%. Soil organic matter content (SOM) is also vital to soil processes like nutrient dynamics, water interactions, and for maintaining the biological and physical health of soil. The low level of SOC content in rainfed drylands is due to rapid decomposition of added organic matter, loss of carbon through soil erosion and use of inappropriate crop management practices. Thus, improving SOC in drylands contributes to productivity enhancement and stability due to higher available water retention during mid-season droughts while improving other soil productivity factors. Therefore, intensive implementation of site-specific available C enrichment technologies in different agro-ecosystems can maintain the overall productivity functions of soil even under adverse conditions. Thus, the present chapter aims to cover the SOC status of rainfed drylands, drought management with improving SOC technologies along with various national programs which address to improve SOC content and stocks in agroecosystems of India. © 2024 selection and editorial matter, Rattan Lal; individual chapters, the contributors.
Integrated nutrient management improves soil organic matter and agronomic sustainability of semiarid rainfed Inceptisols of the Indo-Gangetic Plains
(John Wiley and Sons Inc, 2021) Ch. Srinivasarao; S.P. Singh; Sumanta Kundu; Vikas Abrol; Rattan Lal; P.C. Abhilash; G.R. Chary; Pravin B. Thakur; J.V.N.S. Prasad; B. Venkateswarlu
Background: Climate and management practices impact the soil organic carbon (SOC) stocks of agricultural soils. Especially under the semiarid climate of India, organic matter is rapidly decomposed, and imbalanced nutrient input further exacerbates its depletion, thus facilitating the decline in soil quality and crop yields. Improving SOC contents through integrated nutrient management (INM), that is, conjunctive use of organic and chemical sources of nutrients, could ameliorate soil health and sustain crop yields. Aim: To assess the potential of the INM approach to enhance the SOC status, soil quality, crop production, and drought adaptation of pearl millet under rainfed conditions. Methods: Nutrient inputs were supplied through mineral fertilizers, organic manures, and a combination of both. SOC sequestration, sustainable yield index, plant-available N, P, K, and water, bulk density, and KMnO4-oxidizable C were estimated. Results: Higher SOC sequestration rate (0.50 and 0.48 Mg ha−1 y−1 in 50% N (fertilizer) + 50% N (farmyard manure), and 50% N (fertilizer) + 50% N (crop residue), respectively) and significant increase in soil fertility were recorded in organically amended treatments. Improvement of 1 Mg ha−1 of SOC stock in the root zone (0.4 m depth) reduced the severity of drought and increased the yield by 38 kg ha−1. Plots under organic amendments suffered less yield losses under short-duration droughts, but this positive effect could only be exploited when the rainfall deficit was up to 25%. Conclusion: Managements that add up to 1.2 Mg ha−1 y−1 SOC are adaptive and climate-resilient strategies in dry semiarid degraded Inceptisols of the Indo-Gangetic Plains. © 2021 Wiley-VCH GmbH
Soil potassium fertility and management strategies in South Asian agriculture
(Academic Press Inc., 2023) Ch. Srinivasarao; Sumanta Kundu; K.V. Rao; A.K. Shukla; A. Subba Rao; Patricia Imas; Nanthi S. Bolan; Rattan Lal; J.V.N.S. Prasad; P.C. Abhilash; G. Ranjith Kumar; R.S. Meena; G. Pratibha; G. Narayanaswami; S.K. Bansal; K.C. Nataraj; M. Jagadesh; K. Mrunalini; S. Jayaraman; M.L. Jat; S.N. Malleswari; Anthony Whitbread; B. Venkateswarlu
Almost one-fourth of the global population live in South Asia (SA) countries with 14% of cultivable land. Most of the countries in the South Asian region are facing multiple challenges like high population growth, declining farm land area, and low productivity in primary and secondary sectors leading to limited employment opportunities. Consequently, both availability and access to food are adversely affected. Regions exposed to natural disasters, tribal and the hilly regions of SA are amongst the most vulnerable in terms of food security. Accelerated efforts are required to ensure that conflicts do not exacerbate the already fragile food situation in SA. Despite recent strong gains in economic growth and agricultural productivity, food and nutritional security remains a major concern in SA. The region has the largest concentration of poverty and hunger in the world, with nearly 40% of the world's impoverished and 45% of the world's undernourished people. The enormity of malnutrition in SA can be gauged from the fact that it is the home to nearly two-thirds of the world's undernourished children. More than 56% of the world's low-birth-weight babies are born in SA. Furthermore, food and nutrition security remain major challenges with a large proportion of the world's poor living here and global hunger index (GHI) at 30.9. Overcoming these twin challenges require actions both at the national and regional level. Among production constraints and yield gaps, imbalanced nutrient use is a critical issue in many of the SA countries, with nutrient application focused mainly on nitrogen (N), leaving the possibility for other plant nutrient deficiencies including phosphorus (P) and potassium (K). In some cases, the use efficiency of N may be low due to losses in the form of N2O emissions, a potent greenhouse gas (GHG), or via leaching with the undesirable offsite effects. Among the primary nutrients, K is an essential nutrient for productivity, food quality and numerous functions in the plant system. It plays a major role in activating ∼60 enzymes, regulating stomatal functions, controlling water relations especially under rainfed crop production, influencing the water balance of plant systems, and underpinning agronomic productivity and sustainability. Negative K balance in soil under intensive cropping is reported because of low external input and large crop removal, leading to large scale K mining in soils. Declining yield trends were observed in several fertilizer experiments 30–40 years long with continuous application of either N alone or NP without K under both irrigated and rainfed crop production systems in the region. Recent K fertility analysis indicates widespread K deficiency in light-textured alluvial soils, red and lateritic soils beside acid soil types in India, Bangladesh, Sri Lanka, and Pakistan. The countries in SA depend largely on imported K fertilizers. Such imported fertilizer should be utilized most efficiently in the light of limited global K mineral reserves and 93% of world total K exports are from five countries viz. Canada (37.12%) followed by the Russian Federation, Belarus, Germany and Israel. Therefore, the current review addresses issues related to the K supplying capacity of soils in various crop production systems in SA, crop K responses, soil test methods followed, emerging issues in soil K fertility, K balance in major cropping systems and rationalizing K recommendations among crops, soil types and agro-ecological regions. The role of K in balanced nutrition, farm productivity, food and nutritional security in these countries is examined. The review also covers the critical role of K in climate change adaptation, mitigation of nitrous oxide (N2O) emissions and improving overall nitrogen use efficiency (NUE) in the SA region. © 2023 Elsevier Inc.