Influence of maize-based conservation agriculture production system (CAPS) on some basic soil indices in the hilly terrains of Odisha

The soils in the hilly terrains of North Central Plateau agro-climatic zones of Odisha are subjected to various kinds of soil degradation due loss of forest cover, accelerated soil erosion, shifting cultivation and intense mining activities, thus rendering them unproductive. The farmers of this zone are traditionally growing maize as the only rainfed crop under high tillage without any scientific agro-techniques. Conservation agriculture production system (CAPS) involving minimum tillage, legume based intercropping and a follow up cover crop has been thought of as the best possible long term solution for this region that not only maintains the quality of environment but also conserves the natural resources keeping it buffered against risks. To study the impact of maize based cropping system with cover crops under conventional and minimum tillage practices, a field experiment has been initiated on the sandy clay loam soils of Regional Research and Technology Transfer Station, OUAT at Kendujhar district during 2011-12. Conventional (CT) and minimum (MT) tillage with maize (M) and maize + cowpea (M+C) were taken in main plots during wet season and horse gram (H), mustard (M) and no cover crop (NCC) in sub-plots during dry season. Soil samples were collected before and at the end of the cropping cycle to study the impact of treatments on soil BD, pH, OC and available N, P and K. The practice of MT reduced the BD in the tune of 1.4% over the initial status of 1.22 Mgm-3 and increased the OC, available N and P by 4.9%, 2.7% and 2.0%, respectively (initial contents: 6.9 g kg-1, 271 kg ha-1 and 15.6 kg ha-1) stabilizing the pH and available K of the soils. Growing maize with cowpea as intercrop (M+C) enhanced the OC and available N contents of the soils by 2.6% and 1.4%, respectively over the initial values of 6.6 g kg-1 and 267 kg ha-1 and favourably maintained the other soil properties. Inclusion of cover crops either maintained or marginally enhanced these basic soil indices. Practice of minimum tillage with maize cowpea intercrop and follow up horse gram as cover crop (MT-M+C-H) seems to have a positive influence on soil properties as indicated by the initial trends viz. decrease in BD (-2.5%), build up of OC (+8%), available N (+5%) and P (+3.6%), stabilizing effect on pH and available K, at the end of first cropping cycle. The positive impact of the same CAPS practiced by twenty participating farmers in the tribal village Tentuli during 2011-12, was also observed on the soil attributes viz. BD (-2.7%), OC (+10.8%), available N (+6.5%), P (+7.8%) and K (+3.1%).