EFFECTS OF CONSERVATION AGRICULTURE PRODUCTION SYSTEM (CAPS) ON SOILORGANIC CARBON, BASE EXCHANGE CHARACTERISTICS AND NUTRIENT DISTRIBUTION IN A TROPICAL RAINFED AGRO-ECOSYSTEM.

Abstract

Conservation agriculture production system (CAPS) with the components of minimum tillage, legume based intercrops and follow up cover crop has been established in a Fluventic Haplustepts at Regional Research and Technology Transfer Station, OUAT, in Kendujhar district ,Odisha during 2011 in triplicated split plot design and the impacts of Conservation Agriculture Production System (CAPS) on soil organic matter, base exchange characteristics and available nutrients were assessed at the end of the 2nd cropping cycle. The treatment combinations are conventional tillage (CT) and minimum tillage (MT) with sole maize (M) and inter crop maize+ cowpea (M+C) in main-plots during wet season and horsegram (H), mustard (T) and no cover crop (NCC) in sub-plots during dry season. The accumulation and preservation of organic matter in MT increased the SOC (+19.9 %), CEC (+11.2 %), Ca++ (+19.9 %), Mg++(+18.3%), K+(+14.9%), base saturation (+6.7%) over t h e s o i l s under CT system. Higher build up of and physical protection of SOM due to less soil disturbances in MT resulted in higher available N (+13.4%), P (+3.9%) and K (+10.1%). The pronounced effect of cover crops due to litter inputs in the cropping system was reflected on enhanced SOC (+6.8%), Ca++ (+6.5%), Mg++ (+5.8%), K+ (+4.7%), available N (+5.1%) and P (+6.3%), over the soils with NCC. Considerable build up of SOC due to residue incorporation and its protection under the CAPS of MT with M+C intercrop and a follow up cover crop contributed significantly in improving the status of CEC (r =0.57**), base saturation (r = 0.54**),available N(r =0.77**), P (r =0.47*) and K(r =0.63**).