林地开垦后对不同质地红壤碳氮和磷库的影响  

Effects of the Reclamation of Forest Land on Organic Carbon,Nitrogen and Phosphorus Pools in Red Soils of Different Texturel

作　　者：夏建强[1] 章明奎[1] 徐建民[1] 

机构地区：[1]浙江大学环境与资源学院资源科学系,浙江杭州310029

出　　处：《土壤通报》2005年第2期185-189,共5页Chinese Journal of Soil Science

基　　金：国家自然科学基金资助项目(49601013)

摘　　要：林地开垦农用后,土壤有机C和总N、P的浓度及在各团聚体粒级中的分布可发生较大的变化。对亚热带山地两类不同质地的红壤研究表明,林地开垦为旱地和茶园后,有机质和全N明显下降,全P呈轻微下降。下降量壤质土壤(黄泥土)大于粘质土壤(黄粘泥)。表土(0～15cm)的有机C和总N、P下降大于亚表土(15～30cm)。在三个团聚体粒级中,砂粒中有机C和总N、P的下降幅度最大,并随粒径变细下降幅度逐渐变小,表明与砂粒和粉砂结合的有机C和N、P易受利用方式的改变而变化。从林地到茶园、旱地,各团聚体粒级中有机P及有机P占总P的比例趋向下降。砂粒和粉砂中Olsen-P也呈下降的趋势。Physical fractionation and chemical analysis were used to a ssess the impacts of land use changes on the amount and compositions of organic carbon, nitrogen and phosphorus in bulk soils and size fractions in two red soil s with different textures in Zhejiang Province. Soil samples of both surface (0- 15 cm) and subsurface (15-30 cm)were collected from natural forest, 24-yr cultiv ation tea plantation and upland on two different parent materials (basalt and tu ff). Forest clearing and continuous cultivation for upland led to significant de pletion of total soil organic C (SOC) (39% and 67%) and N (30%and 61%) in surfac e soils respectively. Compared with the cultivated upland, lower proportions of SOC (28% and 44%) and N (20% and 42%) were lost from the tea plantation respect ively. The largest depletion occurred in the labile SOM associated with the sand fractions. The results suggested that the SOM in the sand and silt was quite su sceptible to land use change.

关 键 词：林地开垦 有机碳 养分库 质地 团聚体粒级 

分 类 号：S153.6[农业科学—土壤学]