少耕秸秆覆盖对小麦间作玉米棵间蒸发的影响研究

在河西绿洲灌区,通过大田试验,研究了前茬小麦25cm高茬收割免耕(T0S1)、25cm高等量秸秆覆盖免耕(T0S2)、25cm高等量秸秆翻压(TS3)和低茬收割翻耕(TS0)对后茬小麦、玉米的单作和间作群体耗水量和棵间蒸发的影响,以期为通过优化小麦间作玉米的秸秆管理、提高水分利用率提供理论依据。结果表明,秸秆覆盖可降低作物群体的总棵间蒸发量,与未覆盖处理相比,秸秆覆盖小麦间作玉米的棵间总蒸发量降低了4.7%~8.9%,单作小麦棵间总蒸发量降低了4.8%~11.2%。间作群体的棵间蒸发主要发生在小麦收获前,约占总蒸发量的70%,秸秆覆盖处理在小麦收获前使棵间蒸发降低了5.2%~10.8%。间作中,小麦带棵间蒸发量较玉米带高16.6%~19.8%；秸秆覆盖处理与未覆盖处理相比较小麦带棵间蒸发量降低了5.4%~10.0%,玉米带棵间蒸发量降低了3.9%~6.1%。秸秆覆盖处理的E/ET相比于无覆盖处理小麦间作玉米群体降低了2.9%~5.2%,单作小麦群体降低了2.1%~9.0%,小麦秸秆覆盖可减少水分的无效损失,提高水分利用率。

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.