林草间作系统土壤微生物及其活性研究

试验对6年龄桉树人工林间作禾本科及豆科牧草后的土壤微生物进行研究，结果表明：间作牧草可显著提高林地土壤微生物的生物量、呼吸强度、硝化作用强度及纤维素分解作用强度，且均随着土层深度的加深而降低；其中以间作热研6号珊状臂形草、热研2号柱花草、GC1581柱花草和Mineirao柱花草的土壤微生物生物量最高；热研15号刚果臂形草、热研6号珊状臂形草、杂交臂形草、热研10号柱花草、Mineirao和GC1581的呼吸强度高于CK；热研11号黑籽雀稗、热研10号柱花草、GC1581和热研2号柱花草的硝化作用强度强于CK；热研9号坚尼草、杂交臂形草和热研6号珊状臂形草、热研10号柱花草和热研2号柱花草的土壤纤维素分解作用强度较强。

Microorganism and Its Activity of the Soil of Silvopastoral Systems

he study was carried out to study the soil microbial under eucalyptus plantations（planted more than 6 years）intercropped with gramineous grass and leguminous grass. The results showed that the intercropping with pasture could significantly promote the biomass, respiration intensity, soil nitrification and cellulase-decomposition intensity of the soil microbial, which also decreased as the soil depth increased. The soil microbial biomass of eucalyptus intercropped with Brachiaria brizantha Stapf. cv. Reyan 6, S. guianensis cv. Reyan No.2, Stylosanthes guianensis GC1581 and Stylosanthes guianensis Mineirao ranked first; the respiration intensity of B. ruziziensis cv. Reyan 15, B. brizantha cv. Reyan 6, B. hybrid FM9201/1873, S. guianensis cv. Reyan 10, S. guianensis GC1581 and S. guianensis Mineirao was stronger than CK; the Soil nitrification of Paspalum atratum cv. Reyan 11, S. guianensis cv. Reyan 10, S. guianensis GC1581 and S. guianensis cv. Reyan No.2 was also better than CK. While P. maximum cv. Reyan 9, B. hybrid FM9201/1873, B. brizantha cv. Reyan 6, S. guianensis cv. Reyan 10, S. guianensis cv. Reyan No.2 had a strong cellulase-decomposition intensity.