不同种植模式下丘岗红壤的酸性和交换性能研究

Soil acid and exchange properties of red soil in hilly regions under different cropping patterns

通过野外采样和室内测定,研究湖南永州市和浏阳市柑橘、油茶、西瓜单作和柑橘间套作、油茶间套作以及荒地模式下的丘岗红壤的酸性和交换性状况。结果表明：不同种植模式下土壤的酸化情况严重（pH值约为4.0）;土壤保肥能力均为中等偏下（CEC为8.7~10.96 cmol/kg）,相比较而言,以油茶间套作土壤的保肥能力较强;柑橘间套作土壤的交换性酸和交换性Al3＋最低,其潜性酸最低,土壤的交换性盐基总量和盐基饱和度最高,其肥力、保肥和缓冲能力最强;供试土壤的交换性酸均以交换性Al3＋为主,占比为92.5%~95.1%,交换性盐基主要为交换性Ca2＋、Mg2＋,占比为82.7%~91.8%;不同种植模式土壤的CEC含量差异显著,土壤pH,交换性酸,交换性Al3＋和交换性K＋、Na＋、Ca2＋、Mg2＋含量差异均不显著。

Soil acid and exchange properties of red soil in hilly regions under continuous cropping of citrus,camellia and watermelon,under intercropping of citrus with camellia,grass,peanut or sweet potato,under intercropping of camellia with watermelon and under wasteland pattern in Yongzhou and Liuyang,Hunan Province were studied through field sampling and laboratory analysis.The results showed that soils under different cropping patterns were acidified seriously with pH value around 4.0 and showed low to middle fertility-preserving capacity with CEC being 8.7？10.96 cmol/kg,and soil with camellia intercropping showed comparatively stronger fertility-preserving capacity.Exchangeable acid and exchangeable Al3＋ were both the lowest in citrus intercropping soil,thus the potential acid was the lowest;exchangeable base content and base saturation were both the highest in citrus intercropping soil,thus the fertility,fertility-preserving capacity and buffering capacity was the strongest.Exchangeable acid in the tested soils mainly existed in the form of exchangeable Al3＋,accounting for 92.5%？95.1%,and the exchangeable base mainly existed in the form of exchangeable Ca2＋ and Mg2＋,accounting for 82.7%？91.8%.The difference of CEC content among soils under various cropping patterns was very significant,while there was no significant difference in soil pH,exchangeable acid,exchangeable Al3＋,exchangeable K＋,Na＋,Ca2＋ and Mg2＋ contents under various cropping patterns.