中文摘要：

采用Hedley修正体系分级法对轮作30年的长期定位土壤进行测定,结果表明,不同施肥条件下各形态磷的基本表现为：有机肥区〉化肥区〉CK,而有机肥和化肥配施能明显增加土壤中各形态磷的含量,从而有效的扩大了土壤磷库。从30年轮作的动态变化来看,CK和单施氮肥处理的NaHCO3-P和NaOH-P含量的变化幅度不大;施磷化肥区NaHCO3-P和NaOH-P的含量随着种植年限的增加而缓慢的上升;有机肥区的NaHCO3-Pi和NaOH-Pi含量不断增加,而NaHCO3-Po和NaOH-Po的含量呈先升高再降低再显著升高的动态变化趋势。棕壤中无机磷主要以NaOH-Pi和HCl-Pi的形态存在,有机磷主要以NaOH-Po的形态存在;不同施肥对NaHCO3-Pi和Res-P所占总浸提磷比例影响较大,施入磷肥和有机肥能提高土壤中NaH-CO3-P的比例;有机肥能促进Res-P的转化并减少Res-P的固定,从而降低了Res-P在土壤中的比例。

英文摘要：

Phosphorus fractions of brown earth selected from 30 years＇ long-term rotation field were measured by classification method revised by Hedley.The results showed that the contents of varied forms of phosphorus under the different fertilizer conditions were in the order of organic manure plot fertilizer plot CK.And the combined application of organic manure and chemical fertilizer could significantly increase different forms of soil phosphorus contents and significantly enlarged soil P pool.Over 30 years＇ rotation,NaHCO3-P and NaOH-P of CK and N fertilizer treatment had not changed greatly NaHCO3-P and NaOH-P increased slowly year by year in phosphorus fertilization plot;NaHCO3-Pi and NaOH-Pi increased continuously with the trend of increasing first and then decreasing and finally significantly increasing again.In this tested brown earth,NaOH-Pi and HCl-Pi were two mainly fractions of inorganic phosphorus,and organic phosphorus mainly existed in the form of NaOH-Po.Different fertilizations influenced the proportions of NaHCO3-Pi and Res-P in the total extracted P.Phosphate fertilizer and organic manure applications could increase the proportion of NaHCO3-P.Organic fertilizer could promote the transformation of Res-P reduce the Res-P fixation and proportion in the soil.