干热河谷不同酸豆林土壤团聚体特征分析

摘要

Experiments were conducted on the soil aggregates underTamarindus indica forest with bared land(L+G)CK), with fireweed(L+Z), with Paspalum notatum (L+B), withPhyllanthus emblica (L+Y), and withCajanus cajan (L+M) in dry-hot valley of Yunnan. R0.25(percentage of soil aggregates with diameter larger than 0.25mm), mean weight diameter (MWD), geometric mean diameter (GMD) and fractal dimension (D) were determined at 3 soil layers (0 - 10 cm, >10 - 20 cm, >20 – 40 cm). The results showed that L+B promoted the conservation of soil macro-aggregates, L+Z and L+G could improve the soil aggregate structure, L+Y and L+M forestlands reduced the proportion of macro-aggregates in the soil but increased micro-aggregates content. The experiment demonstrated that in dry-hot valley, conservation tillage was conducive to the sustainable management ofT. indica.%采用干筛法对金沙江干热河谷区酸豆林＋光板地（裸地）、酸豆林＋杂草、酸豆林＋百喜草、酸豆林＋余甘子、酸豆林＋木豆5种酸豆林地在0~10 cm、>10~20 cm、>20~40 cm的3个土层中的R0.25、MWD、GMD和分形维数D变化进行研究，结果表明：5种酸豆林模式中，酸豆林＋百喜草模式有利于土壤大团聚体的保存，酸豆林＋杂草模式和酸豆林＋光板地模式提升土壤团聚结构，但是效果并不显著，而酸豆林＋余甘子模式和酸豆林＋木豆模式则降低了土壤中大团聚体的比例，使土壤中的微团聚体含量增加；在干热河谷实施保护性耕作有利于酸豆林的可持续经营。