秸秆深还田两年对东北半干旱区土壤有机质、pH值及微团聚体的影响

采用田间小区定位试验，探讨秸秆深还田2 a对东北半干旱区旱田土壤有机质、pH值、微团聚体的影响。结果表明:秸秆深还田后降低了土壤的pH值，且随土层深度的增加pH值逐渐增大；土壤有机质含量和微团聚体的团聚度在秸秆深还田各处理中分别高于CK和DT处理3.4%～32.7%和16.4%～53.7%，土壤分散系数较CK和DT处理显著降低，均以秸秆深还田用量12 000 kg/hm²效果最好。秸秆深还田2 a后能够显著提高东北半干旱区土壤有机质含量，降低土壤pH值，改善颗粒组成状况，降低土壤分散系数，提高微团聚体的团聚度。

Effects of Two Years of Stalk Deeply Returned to the Field on Soil Microaggregates and Soil Organic Matter and pH Value after in Semiarid Region of the Northeastern China

A field experiment was conducted. Soil microaggregate and mechanical property was separated by pipette and sieve analysis, and soil organic matter, pH and soil micro-aggregate were measured. The effects of stalk deeply returned to the field after two years on oil organic matter, pH and soil microaggregate in semiarid region of the northeastern China. The Results indicate that stalk deeply returned to the field decreased the soil of pH. As the depth of soil layers increased, pH value increased gradually. The amount of soil organic matter and soil microaggregate degree were higher than the CK and DT treatments of stalk deeply returned to the field 3.4%～32.7% and 16.4%～53.7%, respectively. Dispersion coefficient of soil was lower than the CK and DT treatments, 12 000 kg/ha treatment of stalk deeply returned to the field was the most significant. In summary, after two years of stalk deeply returned to the field could improve the amount of soil organic matter, decrease the soil of pH, improve the characteristics of particle composition of soil, positive effects on soil microaggregation degree.