[Effect of different mulching on spring corn yield and on soil environment in Loess Plateau]

Effects of different mulching on spring corn yield and on soil environment in Loess Plateau, Heyang County were studied. The results showed that different mulching could increase the corn yield significantly. Soil water contents were increased remarkably except normal plastic film mulching, and the upper soil layer kept wet for a long time. Mulching could also reduce temperature difference of day and night, keep soil surface from direct precipitation lash, and maintain better soil structure. Compared with straw mulching, normal plastic film and no mulching, water osmosis plastic film could increase the yield by 6.4%, 23.6% and 29.1%, the water use efficiency 21.5, 20.2, 17.4 and 16.7 kg.mm-1.hm-2, respectively. Straw mulching could remarkably increase soil organic matter and soil fertility. Water osmosis plastic film had the same effect of increasing temperature as normal plastic film. While air temperature was more than 35 degrees C, water osmosis plastic film had the function of reducing extreme temperature, but long term mulching would promote excessive mineralization of soil organic nitrogen and leaching of NO3(-)-N.