不同秸秆施用方式下接种蚯蚓对土壤团聚体及其中碳分布的影响

Effects of Earthworm Activity on Soil Aggregates' Stability and Organic Carbon Distribution Under Different Manipulations of Corn Straw

通过宦内培养试验，研究在施用有机物条件下接种蚯蚓对土壤团聚休的分布、团聚体的水稳性以及不同粒径的水稳性团聚体中有机碳含量的影响。干筛结果表明，不同秸秆施用方式下，蚯蚓接种能最著促进各个处理中〉2mm团聚体含量的增加，且在秸秆混施的处理中表现得尤为明显，团聚体含量增加了2．95倍；湿筛结果表明，蚯蚓在不施和混施秸秆的处理中能显著降低土壤黏砂粒含量，即增加土壤中水稳性团聚体的含量，但是在表施秸秆的处理中显著降低了0．25-0．053mm粒级团聚体含量，使之分散为黏砂粒。蚯蚓和秸秆对土壤团聚体分布和水稳性的影响都达到显著水平。蚯蚓对水稳性微团聚体的影响极显著．而秸秆的作用更多地表现在水稳性大团聚体上。在秸秆表施和秸秆混施条件下，接种蚯蚓均显著促进了微团聚体碳含量的增加，分别为相应对照的2．1和1．2倍。蚯蚓作用能显著降低黏砂粒有机碳在全碳中含量。增加团聚体有机碳含量，主要是由于蚯蚓的作用能促进黏砂粒黏结为团聚体。

This short–term laboratory experiment conducted to determine the effects of earthworm activity under residues using on the distribution and water stable ability of soil aggregates and the distribution of soil organic carbon in water stable aggregates with different diameter. The results showed that earthworm inoculation significantly increased the content of large-macro aggregates in all the treatments （p〈0.05）, while decreased the content of other aggregates with no significant differences, which implied that earthworms transformed clay and micro-aggregates into macro aggregates （by dry sieving）, especially in SRME treatment. Earthworm inoculation also increased the content of soil water-stable aggregates when no residues used or the residue mixed （by wet sieving）, and the result was opposite when residue covered and in SRCE treatment, the content of water-stable aggregates （0.25 - 0.053 mm） was seriously decreased by the earthworm inoculation. The content of total organic carbon in clays was higher than that in water-stable aggregates except in SRCE treatment, and earthworm inoculation could decrease the percentage of clay carbon and increase the percentage of aggregate carbon. Earthworm inoculation and residues application could significantly affect the distribution and water stable ability of soil aggregates. Earthworm inoculation mainly affected water stable micro-aggregates, while the residues application mainly affected macro-aggregates, and there were significant correlation between the water stable aggregates and MWD, so it can be concluded that the residues application was the main factors affecting water stable aggregates. Further, earthworm inoculation significantly affected the distributions of soil organic carbon in soil aggregates with different diameters.