覆盖措施对雷竹林地土壤硝化和反硝化作用的影响

Effects of mulching on soil nitrification and denitrification in a Phyllostachys violascens stand

为探讨林地覆盖对雷竹林土壤硝化和反硝化作用的影响,以不覆盖雷竹林为对照,测定了林地覆盖期间(覆盖后30、60、90 d)雷竹林土壤基本理化性质,并用气压分离过程技术(Ba PS)测定了土壤硝化速率和反硝化速率。结果表明:覆盖措施和覆盖时间对雷竹林土壤硝化和反硝化作用均有显著影响,而且两者存在明显的交互作用;覆盖能促进雷竹林土壤反硝化作用,但长时间覆盖会抑制雷竹林土壤硝化作用;覆盖总体上会降低雷竹林土壤硝化速率、反硝化速率与土壤理化性质的相关性程度,并使土壤硝化和反硝化作用的主要环境影响因子趋于多样化和复杂化;覆盖雷竹林土壤硝化速率的主要环境影响因子是土壤含水量、p H值、铵态氮含量和总孔隙度,反硝化速率的主要环境影响因子是土壤p H值、含水量和总孔隙度。林地覆盖会显著影响雷竹林土壤的氮循环过程,可能会增加土壤氮素损失。

The rates of nitrification and denitrification in Phyllostachys violascens stand with and without mulching were measured by the barometric separation process technology（ Ba PS）,and basic soil physicochemical properties were evaluated after covering 30,60,and 90 d. The results showed that both mulching and covering duration had a significant impact on nitrification and denitrification,and these two factors interacted with each other. Mulching enhanced denitrification,but prolonged mulching inhibited nitrification. In general,mulching reduced the correlation between the rates of nitrification and denitrification and soil physicochemical properties. Meanwhile,it diversified and complicated the major environmental factors on nitrification and denitrification. Our results suggest that mulching could affect soil nitrogen cycling processes in the P. violascens stand,increasing nitrogen loss in the soil.