Soil physical properties and wheat performance under various preparatory tillage practices in a subtropical dry land of Pakistan

摘要

Conventional methods of seed bed preparation involve intensive tillage which not only deteriorate the soil physical health but also increase input cost for resource poor farmers of developing countries. A field experiment was conducted to evaluate different less intensive tillage systems on soil physical properties and wheat yield. The tillage treatments applied at the time of wheat planting were minimum tillage (MT), rotavator (RT), disc plough (DP) and cultivator (CT) arranged in RCBD layout. Soil bulk density was lowest under DP at 0-15 cm and under MT at 15-30 cm soil depth. Consequently the highest total soil porosity was observed under DP at 0-15 cm depth and under MT and DP at 15-30 cm depth. Soil water content measured twelve times during crop period did not show significant difference among tillage treatments. Mean values of soil water content were 8.20% at 0-15 cm depth and 9.29 at 15-30 cm depth. Wheat biomass yield was higher under DP and MT than RT and CT. Grain yield was highest under DP followed by MT that was signifcnalty higher than CT. Regression analysis showed that variation in biomass and grain yield of wheat was mainly explained by the differences in bulk density with r2 values of 0.566 and 0.623, respectively. The study indicates that minimum tillage and disc plough can be used as an alternative to conventional intensive tillage systems for better soil physical health and wheat crop in subtropical dry land conditions.