河西灌区免耕秸秆覆盖对春小麦播种及出苗的影响

Effects of no tillage with stubble mulch on sowing and seedling of spring wheat in the Hexi Irrigation Area

在河西灌区储水灌溉条件下进行了秸秆覆盖免耕（NTS）、秸秆还田（CTS）和常规耕作（CTB）对春小麦播种出苗影响的试验研究．结果表明，在春小麦的播种期，3种耕作方式的平均日均地温变化趋势一致，均随着土壤深度的增加而减小，且在同一时间NTS的地温小于相同土层CTS和CTB,NTS在5cm处14：00的地温比CTS和CTB分别低0．7～4．6℃和1．2～6．1℃．NTS的地温日变化趋势相对缓和．苗期全天5cm处的地温NTS比CTS和CTB分别低-1．40～2．90℃和-0．60～3．70℃。NTS造成的“低温效应”对种子发芽不利，所以尽管NTS的播种时间比CTB和CTS推迟了一周，但出苗率仍远低于CTS和CTB．

Effects of no tillage with stubble mulch （NTS）,conventional tillage with straw incorporated （CTS） and conventional tillage with bare ground （CTB）on seedling of spring wheat under storage irrigation condition in Hexi Irrigation Area were studied. It showed that during the sowing time of spring wheat, the variations of soil temperature in three tillages pattern were consistent. The soil temperature that 5 cm under ground of NTS was 0.7～4.6 ℃ and 1.2～6.1℃ lower than CTS and CTB,respectively. Daily variation of soil temperature of NTS was gentle comparing to CTS and CTB. During seedling time, the temperature of soil that 5 cm under ground of NTS was —1.40～2.90 ℃ and —0. 60～3.70℃ lower than that of CTS and CTB. Caused by this obvious effect of low soil temperature of NTS which was harm to the germination of seeds,although the sowing time was a week later than CTS and CTB,the seedling rate of spring wheat was still very low.