多熟制条件下节水抗旱农作模式的水分利用率研究

Study on water using efficiency in the model of water-saving and drought resistance in multiple cropping farming system

本研究利用前作秸秆覆盖后作和周年免耕，通过相应的技术集成，形成高效节水抗旱农作模式，将抑蒸保墒和培肥地力结合起来，达到节水抗旱、轻简高效又有利于资源循环利用、可持续发展的目的。结果表明：模式1（小麦-水稻-秋菜，周年免耕，旱季稻草全田覆盖，水稻季麦秸宽行覆盖，作物秸秆全部还田）和模式2（马铃薯／油菜-水稻，周年免耕，旱季稻草垄上覆盖，水稻季油菜秸秆宽行覆盖，作物秸秆全部还田）与CK1（小麦-水稻，翻耕，不覆盖，作物秸秆全部移除）和CK2（油菜-水稻，翻耕，不覆盖，作物秸秆全部移除）相比，可提高土壤耕作层土壤含水量、储水量和水分利用率，平均周年节水2600m^3·hm^-2以上，可充分利用秋季光热资源，增种短季秋菜创造较高的效益，同时不耽误小春作物的种植，增加经济效益15000-21000元·hm^-2，实现了节水高产高效。

High efficient water-saving and drought resistance models were formed by using the straw of foregoing crops covering following crops, zero-tillage around the year and correspond technology combination, which inhibit transpiration ,preserve soil moisture and fertilize soil while achieving the purpose of water-saving and drought resistance ,convenience and efficiency, resource recycling use and sustainable development. The results showed that model 1 （vegetable-wheat-rice,zero-tillage around the year,straw of rice mulching full field in dry season, straw of wheat mulching on wide rows in rice season,all crop straw returning back to field） and model 2 （potato/rape-rice,zero-tillage around the year,straw of rice mulching on ridge,straw of rape mulching on wide rows in rice season,all crop straw returning back to field）, compared with CK1 （ricewheat,conventional tillage with moving out crops straw ） and CK2 （ rape-rice,conventional tillage with moving out crops straw ）, increased in soil moisture, water storage capacity and water using efficiency, which saving water of more than 2600 m^3·hm^- 2 averagely in a year and increase economic benefits of 15 000 -21 000 yuan·hm^-2. So two research models showed good results in watersaving,high yield and efficiency.