长期施肥条件下设施栽培土壤无机磷组分及其剖面分布特点

采用张守敬和Jackson(1957年)提出的土壤无机磷分组测定方法,对施肥17年的蔬菜保护地土壤无机磷的形态及其剖面分布规律进行了研究。结果表明,土壤无机磷组分及其剖面分布受施入的有机肥影响较大。施有机肥组(A组),土壤中O-P含量占无机磷总量百分数最高,平均为35%～47%;不施有机肥组(B组),土壤中Ca-P含量占无机磷总量百分数最高,平均为29%～39%。长期施用有机肥能够增加20cm以下土层中无机磷含量;施有机肥组(A)和不施有机肥组(B)各处理土壤不同形态无机磷含量均随土层加深而逐渐降低,但在0～60cm土层内,有机肥组不同形态无机磷含量均高于不施有机肥组。长期施用磷肥会增加土壤中无机磷的积累量,而且有效性较高的Ca-P、Al-P积累程度高于较稳定的O-P、Fe-P积累程度。

Fraction and Distribution of Soil Inorganic P in Protected Cultivation under Long-term Fertilization

This study deals with the fraction and distribution of soil inorganic P in a 17-year fertilization experiment under the protected cultivation using the method of Zhang and Jackson. Results indicated that long-term fertilization of organic manure had significant effect on soil inorganic P fraction and its distribution in the profile. In organic manure group (Group A), the percentage of soil O-P content was the highest in the soil inorganic P (35%-47%), whereas in non-organic manure group (Group B), soil Ca-P content was the highest in the soil inorganic P 29%-39%. Long-term fertilization of organic manure could increase the inorganic P below 20 cm soil layer. The content of various forms of inorganic P decreased with the increasing soil layer in the groups A and B. However, the contents of various forms of inorganic P in the group A were higher than those of the group B throughout 0-60 cm layer. Long-term P fertilization could increase the accumulation of inorganic P in the soil, and it could increase more accumulation of Ca-P and Al-P than O-P and Fe-P.