The Affects Of Different Land Use Patterns On Soil Fertility Quality In Red Soil Hilly Region

The soil acid and exchangeable properties, and primary, secondary and micro-nutrient status of the soils under different intercropping pattern of citrus, camellia and other short crops in red soil hilly regions of Yongzhou and Liuyang in Hunan Province were researched through the field investigation and laboratory analysis, In addition, the comprehensive evaluation method of fuzzy mathematics was also used to make a comprehensive evaluation on soil fertility quality status of the tested soils. The results showed as follows:(1) soil acidification under4intercropping patterns is all terrible. All soils’pH is below4.5and about4.0, while their exchangeable acid is very high and amounts to about5.0cmol/kg. The citrus intercropping mode(A) soil’s exchangeable acid and exchangeable Al3+is the lowest and shows the highest exchangeable base content and base saturation. it is indicated that The citrus intercropping mode(A) soils has better fertility and the strongest nutrient-preserving capacity and buffering capacity. All soils’exchangeable acidity mainly exists in the form of exchangeable Al3+, and exchangeable base mainly exists in the form of exchangeable Ca and exchangeable Mg, exchangeable Ca especially. The difference in CEC among different intercropping patterns’soils was very significant, while the difference in soil pH, exchangeable acid, exchangeable Al3+, exchangeable K, Na, Ca and Mg content among different intercropping patterns’was not significant. the CEC、ECEC and base saturation of adult camellia forest is higher than that of young camellia forest.(2) soil organic matter and total N contents are very low under all intercropping patterns. their total P and K contents are middle, readily available K and hydrolysable N content are middle low, but their available P content is abundant. available Ca, Mg, S, Fe, Mn, Cu, Zn and B contents are all abundant while different intercropping patterns’soil available Si and Mn contents are lower than that of wasteland(D), and it shows that the soils’Si and Mn has not been effectively incorporated due to local soil parent material. So we should add Si and Mn fertilizers to the soils appropriately. The differences in soil organic matter, macro-nutrients, available Mg, S, Fe, Si, Mn, Cu and Zn contents among different intercropping patterns were all not significant, while the difference in available Ca content among them was significant. The difference in soil’s available B content among camellia intercropping mode(B) and other modes were all significant; Large-, medium-and micro-nutrient status of the soils in adult camellia forest is higher than young camellia forest.(3) The comprehensive evaluation method of fuzzy mathematics was used to make a comprehensive evaluation on soil fertility quality status under4intercropping patterns of agriculture and forest. The soil fertility quality of citrus intercropping mode(A), camellia intercropping mode(B) and single-mode(C) belongs to the high level, i. e. grade Ⅱ; wasteland(D) belongs to the lowesr level, i. e. grade III. The evaluation result shows this region should perform deepen plowing, application of organic fertilizer, and balanced fertilization to improve and enhance soil fertility level; wasteland due to lower fertility levels, mostly located on steep slopes and difficult to develop, we may sow grass or wild leguminous crops. Thus we can make full use of advantage of the subtropical monsoon climate zone biological resources cycle speed advantage and create good conditions for development of wasteland resources.