S D Bairagi

Bio: S D Bairagi is an academic researcher. The author has contributed to research in topics: Climate change & Water use. The author has an hindex of 2, co-authored 2 publications receiving 20 citations.

Increased arid and semi-arid areas in India with associated shifts during 1971-2004

Abstract: Climate change is one of the major challenges in 21st century faced by Agriculture in India, more so in the Semi-Arid Tropics (SAT) of the country. In recent years, natural and anthropogenic factors have impacted climate variability and contributed to a large extent to climate change. Based on one degree gridded data of India Meteorological Department (IMD) for 34 years (1971-2004), climatic water balances are computed for 351 pixels in India and used for classifying in to six climate types following Thornthwaite’s moisture regime classification and areas falling under different climatic zones in India are delineated. Considerable changes in the country’s climate area observed between the two periods; 1971-90 and 1991-2004. Increased semi-arid area by 8.45 M ha in five states viz., Madhya Pradesh, Bihar, Uttar Pradesh, Karnataka and Punjab, and decreased semi-arid area by 5 M ha in eleven states, contributed to overall increase in SAT area of 3.45 M ha in the country.Overall, there has been a net reduction of 10.71 M ha in the dry sub-humid area in the country. Results indicated that dryness and wetness are increasing in different parts of the country in the place of moderate climates existing earlier in these regions. ICRISAT’s Hypothesis of Hope through Integrated Genetic and Natural Resources Management (IGNRM) using climate ready crops and Integrated Watershed Management could be a potential adaptation strategy by bridging the yield gaps for developing climate resilient agriculture in the country.

Assessing impacts of projected climate on pigeonpea crop at Gulbarga

Abstract: Pigeonpea [Cajanus cajan(L.) Millsp] is an important semi-arid legume crop in India. In Karnataka, pigeonpea is largely grown in the northern parts of the state especially in Gulbarga, which is called “Pulse Bowl of Karnataka”. Climate change is one of the major challenges being faced by agriculture in the Semi-Arid Tropics (SAT) of the country. Pigeonpea productivity in Gulbarga is affected by large variations in rainfall amount and distribution, increased temperatures, depleting soil productivity and disturbing water balance. Based on daily weather data of 41 years (1969-2009), productivity and water use of pigeonpea under eleven climate scenarios are assessed using the pigeonpea model in Agricultural Production Systems Simulator (APSIM). Simulations are done with automatic sowing based on rainfall and soil moisture availability during the sowing window (15 Jun to 20 Aug) and following recommended crop management practices. Simulations show that increase in temperature by 2°C could reduce pigeonpea yields by about 16%. Rainfall decrease of 10% from present coupled with 2°C increase in temperature could reduce yields further by 4%, making the total reduction to be at 20%. Crop duration was shortened by about 10 days and water use reduced by 25 mm with increase in temperature. Increased rainfall scenarios have considerably reduced the adverse effects of higher temperature. Breeding of varieties tolerant to higher temperature and adoption of better water management (both in-situ and ex-situ) practices achieved through integrated watershed approach could play a major role in sustaining pigeonpea productivity under future climate scenarios.

Enhancing Resource Use Efficiency Through Soil Management for Improving Livelihoods

Abstract: Sustainable intensification and improvement in farm-based livelihoods particularly in dryland tropics are the biggest challenges of the century Widespread soil degradation, growing water scarcity, and looming threat of climate change further compound the problem of achieving food and nutritional security along with improved livelihoods Large yield gaps in drylands provide a huge opportunity to increase the food production for future food security and mainstreaming of drylands Soil management for correcting micro and secondary nutrient deficiencies has shown to increase crop productivity by 20–66% in Karnataka, India During 2009–2013 in this state, more than 5 million farmers benefitted and net economic benefits through increased production were estimated to the tune of US$353 million (Rs 1963 crores) Balanced nutrition led to increased nitrogen uptake efficiency, utilization efficiency, and use efficiency for grain yield and harvest index Best practices like soil test-based fertilization including micronutrients and improved cultivars also contribute to increasing rainwater use efficiency in crops by channelizing unproductive evaporation loss into productive transpiration In current rainy fallow regions, the landform management like broadbed and furrow along with balanced nutrition has shown that fallow lands in black soil regions in Madhya Pradesh can be successfully cultivated to grow soybean crop Similarly soil fertility management along with other best practices provides opportunities for intensification through cultivating 114 million ha rice fallow in India by growing of early maturing chickpea Thus, efficient rainy and post-rice fallow management is a way forward to enhance land use efficiency for higher productivity and incomes Along with productivity and economic benefits, improved soil-nutrient-crop-water management is found to contribute to organic C building, enhancing microbial activity and resilience building of production systems Efficient soil management thus serves as a foundation to enhance livelihoods through resource-efficient production and providing opportunities for scaling up

Impact of Rainwater Harvesting on Hydrological Processes in a Fragile Watershed of South Asia.

Abstract: Agricultural water management (AWM) interventions play an important role in ensuring sustainable food production and mitigating climate risks. This study was carried out in a watershed located in a low rainfall (400–600 mm) region of western India. The Soil and Water Assessment Tool model was calibrated using surface runoff, soil loss, and reservoir storage levels, between the year 2000 and 2006. The investigation indicated that the various AWM interventions increased groundwater recharge from 30mm/year to 80 mm/year and reduced surface runoff from 250 mm/year to 100 mm/year. The intervention structures were refilled two to three times during the monsoon season depending on rainfall intensity and duration. The interventions have the advantage of building a resilient system by enhancing groundwater availability even in dry years, stimulating crop intensification and protecting the landscape from severe erosion. The results indicate that soil erosion has been reduced by more than 75% compared to the nonintervention situation. Moreover, the AWM interventions led to the cultivation of 100–150 ha of fallow land with high-value crops (horticulture, vegetables, and fodder). Household income increased by several folds compared to the nonintervention situation. The study showed about 50% reduction in downstream water availability, which could be a major concern. However, there are a number of ecosystem trade-offs such as improved base flow to the stream and reduction in soil loss that should be considered. The study is of great importance to stakeholders to decide on the optimal design for AWM interventions to achieve sustainable development goals.

Identifying potential zones for rainwater harvesting interventions for sustainable intensification in the semi-arid tropics

Abstract: Decentralized rainwater harvesting (RWH) is a promising approach to mitigate drought in the drylands. However, an insufficient understanding of its impact on hydrological processes has resulted in poor resource planning in this area. This study is a meta-analysis of 25 agricultural watersheds representing a range of rainfall and soil types in the semi-arid tropics. Rainfall-runoff-soil loss relationship was calculated at daily, monthly and yearly levels, and the impact of RWH interventions on surface runoff and soil loss was quantified. A linear relationship was observed between daily rainfall and surface runoff up to 120 mm of rainfall intensity, which subsequently saw an exponential increase. About 200-300 mm of cumulative rainfall is the threshold to initiate surface runoff in the Indian semi-arid tropics. Rainwater harvesting was effective in terms of enhancing groundwater availability (2.6-6.9 m), crop intensification (40-100%) and farmers' incomes (50-200%) in different benchmark watersheds. An average of 40 mm of surface runoff was harvested annually and it reduced soil loss by 70% (3 ton/ha/year compared to 1 ton/ha/year in non-intervention stage. The study further quantified runoff at 25th, 50th and 75th percentiles, and found that more than 70% of the area in the Indian semi-arid tropics has high to medium potential for implementing RWH interventions.