西双版纳地区不同胶农复合林对土壤理化性质的影响

对云南西双版纳地区橡胶-大叶千斤拔、橡胶-可可、橡胶-茶叶、橡胶-龙血树4种较典型的胶农复合林和单层橡胶林的土壤理化性状进行研究,并利用主成分分析法评价,揭示不同胶农复合林的土壤特性差异,为单层橡胶林的胶农复合林改造提供理论依据。结果表明,单层橡胶林的土壤有机质含量、土壤容重、土壤含水量、土壤总孔隙度及土壤导水率与橡胶-大叶千斤拔、橡胶-可可、橡胶-茶叶、橡胶-龙血树等4种胶农复合林土壤的相应指标均具有显著性差异(P0.05);单层橡胶林改造为胶农复合林后,土壤有机质含量和全氮含量增加幅度分别为21.3%~50.1%和26.2%~39.9%,同时土壤容重降低,土壤孔隙度增加,土壤含水量与导水率显著增加。在西双版纳地区,将单层橡胶林改造为胶农复合林可提高土壤肥力、保持水土,是较理想的生态农业模式。

Effects of Different Types of Rubber-Based Agroforestry Ecosystems on Soil Physicochemical Properties in Xishuangbanna

To study effects of different types of rubber-based agroforestry ecosystems on soil physicochemical properties, soil samples from four rubber-based (Hevea brasiliensis) agroforestry ecosystems with different interplants (Camellia sinensis, Theobroma cacao, Flemingia macrophylla and Dracaena americana) and rubber monoculture in Xishuangbanna were analyzed and their physicochemical properties were comprehensively evaluated by principal component analysis (PCA), which provided a scientific basis of conversion rubber monoculture to rubber-based agroforestry ecosystem. The results showed that the soil water content, soil organic matter(SOM), soil bulk density, total soil porosity and soil hydraulic conductive in rubber monocultures were significantly different(P<0.05). In addiction, after conversion rubber monoculture to rubber-based agroforestry ecosystem, the content of SOM and total nitrogen increased by 21.3%—50.1%and 26.2%—39.9%, respectively. Meanwhile the values of bulk density decreased and soil water content, total soil porosity, soil hydraulic conductive increased greatly. It was further showed that conversing rubber monoculture to rubber-based agroforestry ecosystem was sustainable ways which could not only improve soil fertility but also conserve soil and water in Xishuangbanna.