不同秸秆还田模式对冬小麦土壤活性有机碳库的影响

Effects of different straw-returning modes on active organic carbon pools in wheat soils

为探寻最适宜小麦种植的秸秆还田模式,优化土壤结构、提升土壤质量,采用根箱培养,以不施肥(CK)为对照,设置不同秸秆还田方式配施化肥共6个处理,即秸秆还田(SF)、秸秆生物炭还田(BF)、秸秆配施腐熟剂还田(SDF)、秸秆配施纳米载体腐熟剂还田(SNDF)以及单施化肥(F).结果表明:所有处理在不同时期的土壤活性有机碳库组分质量分数基本表现为随土层的加深而降低,SNDF处理在小麦成熟期的表层土壤总有机碳(SOC)、土壤可溶性有机碳(DOC)、土壤微生物量碳(MBC)质量分数分别为36.40 g/kg、491.56 mg/kg、273.10 mg/kg,土壤碳库管理指数为225.7%,SDF在小麦成熟期的土壤活性有机碳(LOC)质量分数为7.79 g/kg,SOC、土壤DOC、土壤MBC、土壤LOC和碳库管理指数之间均存在极显著的正相关性(P<0.01).研究发现SNDF处理对冬小麦土壤有机碳组分及土壤碳库管理指数的改善效果最好,该结果为秸秆还田与化肥配施在农业生产上的应用提供了理论依据和研究基础.

This experiment was conducted to find out the most suitable straw return mode for wheat cultivation,to optimize soil structure and to improve soil quality.In this study,we used root box culture,no fertilizer(CK)as the control,and set up six treatments,namely:straw-farming(SF),straw-biochar-farming(BF),straw-decomposing(SDF),straw-nanocarrier-decomposing(SNDF),and fertilizer-application alone(F),for the different methods of strawfarming and fertilizer application.The results showed that the contents of soil active organic carbon pool components in all treatments at different times generally decreased with the deepening of the soil layer,and the contents of total soil organic carbon(SOC),soil soluble organic carbon(DOC),and soil microbial biomass carbon(MBC)in the surface soil of SNDF treatment at the maturity stage of wheat were 36.40 g/kg,491.56 mg/kg,273.10 mg/kg.And the soil carbon pool management index was 225.7%;the soil LOC content of SDF was 7.79 g/kg at the maturity stage of wheat;and there was a significant positive correlation between SOC,soil DOC,soil MBC,soil LOC,and the carbon pool management index(P<0.01).In conclusion,the SNDF treatment had the best effect on the improvement of soil organic carbon fractions and soil carbon pool management index in winter wheat,and the results provide a theoretical basis and research foundation for the application of straw return and fertilizer blending in agricultural production.