【摘要】 为了探讨黑河流域保护性耕作对土壤生产力的影响,设计20cm留茬(NS20),20cm留茬压倒(NPS20),40cm留茬(NS40),40cm留茬压倒(NPS40)和传统耕作(CT)5个处理,研究了黑河流域保护性耕作对农田土壤有机质、土壤微生物量C、土壤微生物量N以及作物产量和水分利用效率的影响。结果表明,保护性耕作农田0—20cm土层土壤有机质、土壤微生物量C和N的含量均高于传统耕作,且其在剖面中的变化趋势基本一致,即随土层深度增加下降;土壤微生物量N有明显的"表聚现象";相关分析表明土壤有机质和土壤微生物量C之间显著正相关(r=0.85,p<0.05),与土壤微生物量N之间无明显的相关关系(r=0.47,p>0.05);保护性耕作提高了春小麦的产量,NPS20和NPS40增产效果最好,较CT分别增产53.08%和46.59%,与CT之间差异达到极显著水平;保护性耕作提高了春小麦的水分利用效率(WUE),NPS20,NS40,NPS40,NS20分别较CT的WUE提高了58.02%,43.40%,47.27%,23.78%。更多还原

【Abstract】 To explore the effects of conservation tillage on soil productivity,a field experiment with the five treatments of no-tillage with 20cm(NS20)and 40cm(NS40)standing stubble,no-tillage with 20cm(NPS20) and 40cm(NPS40)pressed stubble and conventional tillage,and conventional tillage(CT)were carried out to study the changes of soil organic matter(SOM),soil microbial biomass carbon(MBC),soil microbial biomass nitrogen(MBN),crop yield and water use efficiency(WUE)in the Heihe River Basin.Results showed that SOM,MBC and MBN in 0—20cm soil layer under conservation tillage,which decreased with increasing soil depth under conservation tillage,were higher than that under CT.MBN significantly accumulated in surface soil under conservation tillage.Correlation analysis showed that MBC was remarkably correlated to SOM(r =0.85and p<0.05),while there were no significant correlation between MBN and SOM(r=0.47and p> 0.05).Conservation tillage improved grain yield and WUE compared to CT.NPS20 and NPS40 had the best yield effects,increasing grain yield by 53.08%and 46.59%compared to CT,respectively.WUEs in NPS20, NS40,NPS40 and NS20 were increased by 58.02%,43.40%,47.27%and 23.78%,respectively.更多还原