Effect of tillage and mode of straw mulch application on soil erosion in the submontaneous tract of Punjab, India

Abstract

The submontaneous tract of Punjab comprising 10% of the state, is prone to soil erosion by water. Soils of the area are coarse in texture, low in organic matter and poor in fertility. High intensity rains during the monsoon season result in fertile topsoil removal. There is an urgent need to control soil erosion in this region so as to improve soil productivity. A field study was conducted to estimate the effect of tillage and different modes of mulch application on soil erosion losses. Treatments comprised two levels of tillage, viz. minimum ( T m) and conventional ( T c) in the main plots and five modes of straw mulch application, viz. mulch spread over whole plot ( M w), mulch spread on lower one-third of plot ( M 1/3), mulch applied in strips ( M s), vertical mulching ( M v) and unmulched control ( M o), in subplots in a replicated split plot design. Rate of mulch application was 6 t ha −1 in all modes. Compared with M o, M w reduced runoff by 33%. Runoff and soil loss were 5 and 40% higher under T c than under T m. Though other modes of straw mulch application ( M 1/3, M s and M v) controlled soil loss better than M o, their effectiveness was less than M w. T m was more effective in conserving soil moisture than T c. Compared with M o, M w had 3–7% higher soil moisture content in the 0–30 cm soil depth under T m. Minimum soil temperature of the surface layer was 1.4–2.4 °C lower under M w than under M o. Straw mulching reduced maximum soil temperature and helped in conserving soil moisture. Minimum tillage coupled with M w was highly effective in reducing soil erosion losses, decreasing soil temperature and increasing moisture content by providing maximum surface cover.