不同开垦年限农田黑土磷素形态及数量变化

试验研究了黑龙江省不同经纬度不同开垦年限的4个地区农田黑土磷素形态分布及数量变化。结果表明:随开垦年限增加的农田黑土,全磷逐渐升高;有机磷含量呈先升高再降低的趋势;速效磷、Al-P、Fe-P、Ca-P呈先降低再升高的趋势;O-P变化不显著;无机磷各组分的绝对变化量排序为Fe-PCa-PAl-PO-P;变化强度为Fe-PCa-PO-PAl-P。对于开垦年限均为100~150年的侵蚀程度不同的双城和宾县农田黑土,宾县侵蚀区黑土全磷、Al-P、Fe-P、O-P、有机磷含量高于双城非侵蚀区黑土;速效磷、Ca-P非侵蚀区高于侵蚀区;黑土由非侵蚀到侵蚀无机磷各组分的绝对变化量排序为Fe-PCa-PAl-PO-P;变化强度为Fe-PCa-PAl-PO-P。黑土的速效磷、有机磷与全磷之间存在极显著的相关性;无机磷中的Ca-P、Al-P、O-P是有效的磷源。

Changes of Phosphorus Contents and Forms in Black Soils from Different Cultivation Years

Phosphorus forms of black soils from different cultivation years in four regions of Heilongjiang Province were investigated in this paper. Results showed that with the increase in cultivation years the total-P content increased, and the content of organic phosphorus increased initially and decreased afterwards. However, the content of available-P, Al-P, Fe-P, Ca-P decreased first and then increased, while O-P content changed slightly. The order of various inorganic-P fractions was Fe-P>Ca-P>Al-P>O-P; and their change intensity was in the order of Fe-P>Ca-P>O-P>Al-P. For black soils under same cultivation year differing in erosion severity in Shuangcheng and Binxian counties, the contents of total-P, Al-P, Fe-P, O-P in eroded Binxian area were higher than those of non-eroded Shuangcheng area, and the contents of available-P and Ca-P in non-eroded area were greater than those of eroded area. From non-eroded area to eroded area, the change of various inorganic-P fractions was in the order of Fe-P>Ca-P>Al-P>O-P while the change intensity was in the order of Fe-P>Ca-P>Al-P>O-P. A significant correlation among organic-P, available-P and total-P was found. Ca-P, Al-P and O-P were effective sources of available phosphorus in these black soils.