滴灌下秸秆覆盖与灌水量对华北冬小麦土壤水分的影响

摘要

This study explored the effects of straw mulching and irrigation amount on soil moisture of winter wheat in the North China Plain in 2014 and 2015.Evaporation (E),soil moisture content of different soil layers (θ),soil surface temperature (Tc),leaf area index and yield were investigated under six treatments,including low irrigation with straw mulching (D1),low irrigation without straw mulching (D2),medium irrigation with straw mulching (D3),medium irrigation without straw mulching (D4),high irrigation with straw mulching (D5),and high irrigation without straw mulching (D 6).The result showed that E of wet zone was generally larger by an average of 16.45mm than that of dry zone,the changes of the dry zone E exhibited more greatly after heavy raining.The average E of each growth period was reduced by straw mulching treatments when compared to non-mulching treatments,with the reduction of 20.45％,24.77％ and 19.14％ under low,middle and high irrigation amounts,respectively,while the changes of E under mulching treatments presented more vigorous intense after heavy raining.The irrigation amounts had no significant effects on E.Straw mulching exhibited a significant interception effect on the irrigation water under low irrigation amount,and preserved soil moisture as irrigation amount rose.Throughout the observation period,E/ET decreased first and increased later,and was significantly affected by irrigation amount,with the average E/ET values being 29.71％,25.64％ and 21.38 ％ for D1,D3 and D5,respectively.Compared to non-mulching treatments,the average E/ET of straw mulching treatments were decreased by 8.93％,3.01％ and 0.44％ under D1,D2 and D3,respectively.Water use efficiency was generally higher under straw mulching treatments relative to non-mulching treatments,and a negative correlation was observed between WUE and irrigation amounts.In summary,the D3 treatment (middle irrigation,straw mulching) was most suitable for drip irrigation of winter wheat in local area due to the better performance of yield and WUE.%试验于2014-2015年在北京市大兴区进行,以冬小麦为研究对象,以秸秆覆盖和灌水量为处理,对各小区棵间蒸发量(E)、土壤各层含水率(θ)、土壤表层温度(Tc)、叶面积指数及产量等指标进行实测与分析.结果表明:滴灌条件下湿润带E普遍高于干燥带,全观测期平均高出16.45 mm,较强降雨后干燥带E的波动更剧烈;秸秆覆盖可以有效减少各生育期E,低、中、高灌水量处理下秸秆覆盖比未覆盖处理分别减少20.45％、24.77％、19.14％,但在较强降雨后秸秆覆盖处理E波动更剧烈,不同灌水量对E影响不显著;低灌水量时,秸秆覆盖对灌溉水有明显的截留作用,中、高灌水量时则起到明显的保墒作用;整个观测期,E/ET 先变小再变大,灌水量差异对E/ET 影响显著,低、中、高灌水量下均值分别为29.71％、25.64％、21.38％;秸秆覆盖和未覆盖相比三种灌水处理E/ET分别减少8.93％、3.01％、0.44％.水分利用效率秸秆覆盖处理要普遍高于未覆盖处理,并与灌溉定额之间呈负相关.整体来看,中灌水量秸秆覆盖处理的产量和水分利用效率均较优,适合当地冬小麦滴灌种植.