Effect of Stubble Mulching and Reduced Tillage on Soil Evaporation in Wheat-maize Intercropping

In order to provide theoretical basis for improving water application efficiency by optimizing the straw management in wheat-maize intercropping, a field experiment was conducted to investigate the effects of 4different straw covering farming patterns on water consumption and soil evaporation of the following wheat and maize under sole cropping and intercropping in the oasis region of Hexi Corridor, Gansu Province. The 4patterns included no-till with 25cm stubble standing (T0S1), no-till with 25cm stubble covering (T0S2), tillage with 25cm stubble incorporated (TS3) and conventional tillage (TS0), meanwhile the pre-wheat stubble was applied for corresponding mulching pattern. The results showed that, the total soil evaporation of different straw mulching intercropping was reduced, furthermore, wheat-maize intercropping and sole wheat cropping were differently decreased by 4.7%~8.9% and 4.8%~11.2% compared with no mulching treatments. Intercropping evaporation mainly occurred at the wheat per-harvest stage which accounted for about 70percent of that, and different straw mulching treatments in this period was reduced by 5.2%~10.8%. The evaporation of wheat strip in wheat-maize intercropping was 16.6%~19.8% higher than the maize strip, that was decreased by 5.4%~10.0% in wheat strip while 3.9%~6.1% in corn strip under straw mulching compared with no mulching treatments. The E/ET of wheat-maize intercropping and sole wheat with straw mulching was decreased by 2.9%~5.2% and 2.1%~9.0% in comparison to no mulching treatments, respectively. It indicated that stubble mulching pattern could reduce invalid use of water and improve efficiency of water application.