| Black soil is known as the most fertile soil of theworld, which has a high research value in agriculture, environmental protection, etc. The black soil area of China is located in the northeast of the Songliao basin, mainly in Heilongjiang, Jilin, Liaoning and Inner Mongolia, four provinces (regions), but the Northeast Black Soil erosion area has problems of black soil degradation in current, soil erosion is the main cause of black land ecological degradation. Black Soil degradation restricts the sustainable development of agriculture in Northeast as a major factor. Black Soil degradation has become as a major factor restricting the sustainable development of agriculture in Northeast. Phosphorus is one of the three nutrients essential for growth and development of plant, but phosphorus is generally considered not easy to move in the soil, excessive fertilizer inputs and unreasonable irrigation manner, greatly increases the risk of leaching of phosphorus. Therefore, how to improve the effective of phosphorus has very important significance in phosphorus study.The black farmland soil which reclamation years from40to150in four areas of Heilongjiang Province as research subjects in this study,reserch the effect of reclamation years on phosphorus fertility characteristics, and to explore the dynamic changes of phosphorus in the black soil, in order to optimize the management of phosphorus in black soil provide a scientific basis.The results of this study showed that:(1) With the reclamation years increasing total-P content increased,and the content of total-P is not significantly reduced in the black soil of non-eroded Shuangcheng area; For the black soil of same reclamation years but different degree of erosion in Shuangcheng and Binxian, the content of total-P, of eroded Binxian area were more than that of non-eroded Shuangcheng area.(2) With the reclamation years increasing the content of Olsen-P, decreased first and then increased; For the black soil of100-150reclamation years but different degree of erosion in Shuangcheng and Binxian, the content of Olsen-P in non-eroded area were higher than that of eroded area.(3) With the reclamation years increasing the content of Al-P, Fe-P, Ca2-P, Ca8-P, Ca10-P decreased first and then increased; the change trend of O-P content was stable; the sequence of the amount of various inorganic-P fractions in total inorganic-P was Fe-P>Ca10-P>Ca8-P>Al-P>Ca2-P>O-P; and their change intensity was as Fe-P> Ca8-P>Ca10-P>O-P>Ca2-P>A1-P. For the black soil of same reclamation years but different degree of erosion in Shuangcheng and Binxian, the content of Ca2-P,Ca8-P, Ca10-P of eroded Binxian area were more than that of non-eroded Shuangcheng area, and the others was non-eroded Shuangcheng area more than eroded Binxian area. the sequence of the amount of various inorganic-P fractions in total inorganic-P was Fe-P> Ca8-P>Al-P> Ca10-P> Ca2-P>O-P; and their change intensity was as Fe-P> Ca8-P> Ca10-P Ca2-P>A1-P>O-P.(4) With the reclamation years increasing the content of organic-P,Labile organic P, moderately labile organic P, moderately resistant organic P, highly resistant organic P increased first and then decreased. the sequence of the amount of various organic-P fractions in total organic-P was moderately labile organic P> moderately resistant organic P> Labile organic P> highly resistant organic P; and their change intensity was moderately labile organic P> Labile organic P> moderately resistant organic P>highly resistant organic P. For the black soil of same reclamation years but different degree of erosion in Shuangcheng and Binxian, the content of organic-P,Labile organic P, moderately labile organic P, moderately resistant organic P, highly resistant organic P of eroded Binxian area were more than that of non-eroded Shuangcheng area; the sequence of the amount of various organic-P fractions in total organic-P was moderately labile organic P> highly resistant organic P> Labile organic P> moderately resistant organic P; and their change intensity was as highly resistant organic P> moderately labile organic P> Labile organic P> moderately resistant organic P.(5) The change of Phosphatase in the black soil of different reclamation years, alkaline phosphatase was mainly in Shuangcheng,the other area were mainly contain acid phosphatase. The active of Acid phosphatase, neutral phosphate, alkaline phosphatase were the most highly in eroded Binxian area. For the black soil of same reclamation years but different degree of erosion in Shuangcheng and Binxian, The active of Acid phosphatase, neutral phosphate of eroded Binxian area were highly than that of non-eroded Shuangcheng area. The change of Phosphatase of other area were stable.(6) In the black soil of different reclamation years,there was the positive significant linear correlation between the total-P and Olsen-P, and there was extremely significant. linear correlation between organic-P and total-P positive linear correlationThere was a correlation between phosphatase and various organic-P fractions. Therefore, to improve the content of phosphatase in black soil, thus affecting the mineralization of organic-P in soil, it can increase the effective phosphorus source in soil to a certain extent.Ca2-P, Ca8-P, Ca10-P,Al-P, O-P, Labile organic P, moderately labile organic P, moderately resistant organic P were effective phosphorus source in the black soil of different reclamation years.They were directly affects the content of Olsen-P in soil. With the reclamation years increasing,there was a change between inorganic-P and organic-P. With the reclamation years increasing and black soil degradation will cause a certain amount of accumulation of organic phosphorus... |
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