Tillage effects on soil physical properties and performance of rice–wheat-cropping system under shallow water table conditions of Tarai, Northern India

This study was conducted for 3 years in silty clay loam (Aquic hapludoll) associated with water tables fluctuating between 0.05 and 0.96 m depths from the surface. Tillage treatments for rice (Oryza sativa L.) were puddling by four passes of rotary puddler (PR), reduced puddling (ReP) for two passes of rotary puddler, conventional puddling (CP) and direct seeding without puddling (DSWP) in four replications. Tillage treatments for wheat (Triticum aestivum L.) were zero tillage (ZT) and conventional tillage (CT) superimposed over the plots of rice tillage treatments. Puddling caused a significant reduction in saturated hydraulic conductivity (Ks), infiltration rate (IR), and specific volume (Rv). The reduction in Ks in the PR plot at 30 days after transplanting was 27 and 46% (3-year average) higher than in the ReP and DSWP plots, respectively, but was statistically at par with that in the CP plot in the surface tilled layer. This indicates that puddling by four passes of rotary puddler and that by conventional method adopted by farmers in those conditions gives the same level of control on percolation rate. Highest rice yield (5607 kg ha⁻¹) was obtained in the PR plot, which was statistically equal to that in the ReP plot. Wheat yield was highest (4020 kg ha⁻¹) in the DSWP plot of rice under CT condition. Total average grain production (rice + wheat) was highest under ReP–CT treatment combination. Results thus show that quality of soil puddle obtained by half the efforts in conventional puddling was sufficient for a significantly high yield of rice with minimum deterioration of soil properties. Similarly, wheat sowing by conventional tillage in such a reduced puddling plots of rice was sufficient for a significantly high yield of wheat.