安徽省土壤无机磷组分状况及施肥对土壤磷素的影响

Contents of Soil Inorganic Phosphorus Fractions in Anhui Province and Effects of Fertilization on Soil Phosphorus

采用石灰性土壤无机磷分级方法，研究了安徽省不同类型土壤无机磷组分含量状况、土壤无机磷组分在土壤剖面中的含量分布以及施用磷肥对土壤无机磷组分含量的影响，结果表明：安徽省土壤无机磷含量高低排序为菜园土〉潮土〉水稻土砂姜黑土〉黄褐土〉黄棕壤〉红壤〉紫色土；土壤无机磷含量的地域分布特征明显，皖北地区土壤无机磷含量明显高于皖南地区。石灰性土壤无机磷组分以Ca—P为主，占土壤无机磷总量的60％左右，其次为O-P，而Fe—P和Al～P含量较少；酸性土壤无机磷组分以O-P为主，占土壤无机磷总量的50％左右，其次为Fe—P和Al—P，Ca—P相对含量小于10％。菜园土无机磷积累特别明显，特别是积累了较多的Ca2—P和Ca8-P。水稻土无机磷组成变化较大，其含量主要取决于水稻土的成土母质。在菜园土的土壤剖面中，上部土层磷素积累明显，菜园土0～20cm土层中无机磷含量与60～80cm土层的比值为4．12，其他类型土壤表土层也有无机磷积累现象。施用磷肥可以明显提高土壤无机磷含量，在作物生长前期，施用的磷主要转化为生物有效性较高的Ca2-,Ca8-P,Al-P和Fe—P，在作物生长后期，O—P和Ca10—P才出现积累。

This paper reported the contents of soil inorganic phosphorus （Pi） fractions, Pi distribution in soil profile in major types of soils in Anhui province and the impacts of fertilization on Pi fractions. The results showed that the order of soil Pi contents in Anhui province was vegetable soil〉fluvo-aquic soil〉paddy soil〉shajiang black soil 〉yellow brown earth〉yellow cinnamon soil〉red earth〉purplish soil. The soil Pi contents was higher in the northern area than the southern area of the province. In the calcareous soils, most Pi was in the form of Ca-P, about 60% of total Pi. The second fraction of Pi was in the form of O-P. The Pi contents in the forms of Fe- P and Al-P were relatively low. In the acid soils, the major Pi fraction was in the form of O-P, about 50% of total Pi. The fractions of Fe-P and Al-P were also high. In contrast, the content of Ca-P fraction was less than 10%. In vegetable soil, soil Pi accumulated obviously, mainly in the forms of Ca2-P and Ca8-P. In paddy soils, the Pi contents varied noticeably among the different fractions, and depended upon their parent materials. The upper layer contained much higher Pi than the lower layers in the all types of soils, particularly in the vegetable soils where the Pi content in 0-20 cm was 4.1 times of that in 60-80 cm. Phosphate fertilization resulted in significant increase of total Pi content in the soils, mainly in the forms of Ca2-P, CA8-P, Fe-P and Al-P in the early period of crop growth. The forms of O-P and Ca10-P were also increased in the later period of crop growth.