摘要
通过2010—2012年的秸秆还田定位试验,利用干、湿筛法研究了不同用量小麦以及玉米秸秆还田后对植烟土壤有机质和团聚体特征的影响。结果表明,随着秸秆还田量的增加,土壤有机质含量、团聚体平均重量直径(MWD)及几何平均直径(GMD)有所增加,但不同秸秆还田对土壤有机质及团聚体特征的效果不同。干筛法测得土壤团聚体的分形维数随两种秸秆还田量增加而减少,湿筛法测得高量玉米秸秆还田(7500 kg/hm2)较低量秸秆还田(1500 kg/hm2)处理的团聚体分形维数显著降低,同时分形维数随着小麦秸秆还田量的增加而降低。等量玉米秸秆较小麦秸秆在提高土壤有机质含量及团聚体特征方面效果较好。土壤有机质与干筛测得MWD及GMD呈极显著正相关,与干筛测得分形维数呈极显著负相关,与湿筛测得GMD及>0.25 mm团聚体含量呈显著性的正相关。总之,通过秸秆还田可增加土壤有机质含量,影响团聚体分布并提高团聚体稳定性。
A field experiment from 2009 to 2012 were conducted to study the effects of different amount of wheat and maize straw returning on soil organic matter and characteristic of soil aggregates in tobacco planting field by dry and wet sieving. The result showed that the soil organic matter, mean weight diameter（MWD） and geometric mean diameter（GMD） all increased with the increasing straw rate. But the effect of different straw returning on soil organic matter and characteristic of soil aggregates were different. The dry sieving results indicated that the fractal dimension decreased with the increasing straw rate. The wet sieving results indicated that the fractal dimension of soil aggregates was significantly lower in the high amount of maize straw returning treatment （7500 kg/ha） than that in the low amount of maize straw returning treatment （1500 kg/ha）. The fractal dimension decreased with the increasing amount of wheat straw returning. Maize straw returning had a better effect on improving the soil organic matter and characteristic of soil aggregate than the wheat straw returning under the condition of the same straw rate. Significantly positive correlations were obtained between soils organic matter and MWD and GMD by dry sieving, and soil organic matter was positively correlated with GMD and the〉0.25 mm aggregates by wet sieving. In conclusion, straw returning could influence the distribution of aggregation and improve the stability of soil aggregates by increasing the soil organic matter.
出处
《中国烟草科学》
CSCD
2014年第3期12-16,共5页
Chinese Tobacco Science
基金
中国烟草总公司山东省公司科技项目(201002)
国家自然科学基金(41201291)
