Climate Change Mitigation and Adaptation Potential of Conservation Agriculture: Effects on Rainwater Use Efficiency, Runoff, Soil Moisture, Soil Organic Carbon and Energy Use

As climate change will likely have adverse effects on agricultural productivity and food security in much of the semi-arid tropics ((SAT, IPCC, 2007), there is need to develop and disseminate production technologies that provide a layer of resilience against such climate change effects on food security. A long-term experiment was initiated at the International Crops Research Institute for the Semi-Arid Tropics (ICRISAT) farm in Patancheru, India in 2009 rainy season to assess the potential of conservation agriculture (CA) as an alternative and resilient production technology for sustainable crop intensification under rainfed situations in the SAT of southern India. Two tillage treatments -- , normal tillage (NT) minimum tillage (MT), and residue management practices -- residue removal (RR) and residue retention (RT) were tested in maize-chickpea sequence and maize/pigeonpea intercropping systems with four replications. The soil of experimental field was Vertic Inceptisol, which according to USDA is classified as a member of the fine, montmorillonite, isohyperthermic family of paralithic Vertic Ustopepts (Vertic cambisol as per FAO classification); slightly alkaline (pH 7.91) with EC 0.22, medium in organic C (0.42 %) and available P (10.61 kgha-1). Here we present effects of tillage and residue management practices on rainwater use efficiency (RWUE), runoff, soil moisture content and soil organic carbon (SOC) during 2010-11 and 2011-12 seasons. Data from integrated digital runoff and soil loss monitoring unit (IDRSMU, Pathak et al., 2011) were analyzed to estimate runoff in different treatment plots in maize-chickpea system. Soil moisture content was measured using the neutron probe (Troxler model 4302) calibrated under same soil