不同土地利用方式下土壤团聚体的组成及稳定性研究

采用野外调查与室内分析相结合的方法.就不同土地利用方式下土壤团聚体的组成及稳定性进行了研究.试验结果表明:(1)干筛处理下土壤团聚体均以>5 mm粒径为主,总体随粒径的减小呈先降低后增加再降低的趋势;湿筛处理下土壤团聚体以<0.25 mm粒径为主,总体随粒径的减小呈先降低后增加的趋势.(2)干筛处理下,平均重量直径和几何平均直径均表现为桉树人工林最大,杉木人工林最小;湿筛处理下平均重量直径和几何平均直径均以杉木人工林最大,枇杷园最小.(3)风干性团聚体的分形维数表现为杉木人工林>茶园>枇杷园>桉树人工林>撂荒地,水稳性团聚体的分形维数表现为枇杷园>撂荒地>茶园>桉树人工林>杉木人工林.

Study on the Composition and Stability of Soil Aggregates under Different Land Use

By the method of field investigation and laboratory analysis, the soil aggregate composition and stability under different land use were studied. The results showed that:(l) Under the conditionof dry sieve, soil aggregates were dominated by > 5 mm particle size and the changes of soil aggregates were from decreasing to increasing and decreasing again with the decreasing of particle size for all the land use types. Under the conditionof wet sieve,soil aggregates were dominated by <0. 25 mm particle size and the changes of soil aggregates were from decreasing to increasing with the decreasing of particle size for all the land use types. (2)under the condition of dry sieve, the average weighted diameter and the geometric mean diameters of soil aggregates were the highest to the Eucalyptus plantation and were the lowest to the Chinese fir plantation. Under the condition of wet sieve, the average weighted diameter and the geometric mean diameters of soil aggregates were the highest to the Chinese fir plantation and were the lowest to the Loquat orchard. (3) The fractal dimension characteristics of dry-aggregates were the following order as Chinese fir plantation, Tea plantation, Loquat garden, Eucalyptus plantation and Abandoned land. The fractal dimension characteristics of water-stable aggregates were the following order as Loquat Garden, Abandoned land, Tea plantation, Eucalyptus plantation and Chinese fir plantation.