Effect of tillage on physical properties of soil underlowland conditions and crop performance in rice-toria system

A field experiment was conducted during 2001–2003 in the lowland rice soils of Kakodonga watershed of Jorhat, Assam, to assess the effect of different tillage treatments on the physical properties of soils and yields of rice and toria in rotation. The puddling index values of lowland soils increased significantly over farmers’ practice (MT1) when puddling was done by power tiller operated cage wheel and rotovator (MT3) and by helical blade puddler (MT2), puddling index was 1.04 and 1.05 times higher in MT3 and MT2 plots respectively, than in MT1 plots. Treatment MT3 resulted in more amounts of water stable aggregates in lower size fraction (0.25 mm). Effect of tillage on mean weight diameter and structural index was not significant. Bulk density of surface (0–0.10m) soils measured at harvesting of rice cut was highest in MT2 plots. Saturated hydraulic conductivity was found to be 3.76 times lower in MT2 plots and 2.45 times lower in MT3 plots than in MT1 plots due to puddling. Rice yield was maximum in MT3 plots. Pestormed for rice crop tillage did not affect the succeeding rabi crop yield. But, rabi tillage affected the yield of rabi crop. Rabi tillage of twice mould board (MB) ploughing and twice rototilling increased the yield of rabi crop toria significantly over farmer's practice.