秸秆还田方式对关中盆地土壤微生物量碳氮和冬小麦产量的影响

Effects of Different Straw Returning Methods on Soil Microbial Biomass Carbon,Nitrogen and Winter Wheat Yield in Guanzhong Plain

为了探究秸秆还田方式对土壤碳氮过程、水热过程和作物产量的影响,对比分析了关中平原无秸秆还田(T0)、秸秆覆盖还田(T1)、秸秆翻压还田(T2)和氨化秸秆翻压还田(T3)4种还田方式对冬小麦生育期土壤微生物量碳(MBC)、微生物量氮(MBN)、有机碳(SOC)、全氮(TN)、温度、水分利用效率(WUE)和产量的影响。结果表明:MBC和MBN在整个生育期大致呈现先增加再降低的趋势,在拔节期达到最大值,不同秸秆还田处理在生育期均能有效增加土壤MBC和MBN含量;不同秸秆还田方式均能增加耕作层SOC和TN含量,且对表层(0—10cm)的影响最为明显,大于下表层(10—20cm);T1、T2和T3在前期可提升土壤温度,T2日均温最大,越冬期后降低日平均地温;T3、T1和T2分别增加地上部生物量19.41%,5.63%和11.19%,增加籽粒产量23.48%,20.17%和13.17%,其中T3增产效果达到显著水平,明显优于其他秸秆还田方式;同对照相比,T3、T2和T1可显著提高WUE 28.73%,15.36%和18.83%。T3提高冬小麦籽粒产量和地上部生物量的效果优于其他秸秆还田方式,建议氨化秸秆翻压还田最为优化,对于关中地区旱作农业秸秆还田技术的完善和实践具有一定的指导作用。

In order to explore the effects of different straw returning methods on soil carbon and nitrogen cycle,soil hydrothermal processes and winter wheat yield,field experiments were conducted to study the effects of different treatments including no straw returning（T0）,straw mulching（T1）,straw plowed into the soil（T2）,and ammoniated straw plowed into the soil（T3）,on soil microbial biomass carbon（MBC）,microbial biomass nitrogen（MBN）,soil organic carbon（SOC）,total nitrogen（TN）,soil temperature,water use efficiency（WUE）and wheat yield in Guanzhong Plain.The results showed that straw returning increased MBC and MBN in the early growth stage and reached the highest levels at jointing stage.Straw returning greatly increased SOC and TN in 0—10 cm soil layer as compared to 10—20 cm depth.Compared to control,T1,T2 and T3 treatments increased the average soil temperature in the early growth stages with the highest value in T2,while slightly decreased after overwintering stages.T3,T1 and T2 increased the grain yield by 23.48%,20.17% and 13.17%,respectively,while the aboveground biomass increased by19.41%,5.63% and 11.19%,respectively.WUE of T3,T2 and T1 increased by 28.73%,15.36% and18.83% compared with that of T0.Among them,T3 showed better performances on crop grain yield and aboveground biomass than other straw returning methods.Our findings suggest that T3 is more suitable for dry land agriculture farming,in terms of improving the soil quality and crop yield in this region.