稻田垄作免耕对土壤真菌多样性分布的影响

在水田长期垄作免耕处理下,研究了土壤真菌多样性及其在不同大小团聚体中的分布.结果表明,垄作免耕处理下,耕层土壤中,真菌主要分布于粒级为1.0～0.25 mm的土壤团聚体中,同时在＞0.053 mm的各级土壤团聚体中垄作免耕处理下真菌数量多于常规轮作处理;垄作免耕处理的各级土壤团聚体中都有毛霉和根霉存在,且1.0～0.25mm土壤团聚体中属类最丰富,其simpson多样性指数为0.93,Shannon多样性指数为1.24,常规轮作下属类丰度没有明显变化.稻田垄作免耕提高了不同团聚体中真菌的数量、多样性,改变了真菌在不同大小团聚体中的分布状况.

Effect of Ridge-No-Tillage on Distribution of Soil Fungi in Different Sizes of Soil Aggregates

Fungi plays an important role in some of soil biochemical processes such as ammoniation, nitrification, nitrogen transformation, cellulose and humus decomposition. Studies on fungi diversity and its distribution in different-size aggregates can help to understand these processes. Effect of ridge-no-tillage on the distribution of soil fungi in different-size soil aggregates were studied. The results indicated that the amount of fungi was the most within the soil aggregates of 1.0 ~ 0.25 mm under ridge-no-tillage, and the diversity of fungi showed similar trends. The amount of fungi were the most within the soil aggregate less than 0.053 mm under rice/rape rotation system. The results indicated that ridge-no-tillage may provide a more favorite micro-environment for microorganisms.