不同施肥方式对土土壤磷素各组分含量的影响

摘要

To clarify the effects of different fertilization approaches on each phosphorus fraction ,this paper studied the contents of soil inorganic phosphors ,organic phosphors and total phosphors with different fertilizations in Loess soil in Chenxiaozhai ,Yangling ,Shaanxi province .The determination of soil inorganic P fractions was analyzed using the method developed by Gu Yichu and Jiang Bofan .The results showed that the Ca-P fraction made up the largest proportion of to-tal soil inorganic P ,regardless of the fertilizer treatment .In particular ,Ca10 -P accounted played a predominant role (28 .77% ~63 .96% ) .With both chemical and organic fertilizer applications ,the inorganic P and organic P concentra-tions were increased ( P<0 .05 ) .The impact of P fertilizer on inorganic phosphorus was greater than organic phospho-rus .The proportions of Ca10 -P and O -P that were invalided to plants became decreased ,while the proportions of available Ca2 -P ,Ca8 -P ,Al-P and Fe-P went increased .The effects of organic fertilizer were better than those of inorganic fertilizer on increasing valid phosphorus in soils .Specifically ,organic fertilizer application increased Ca2 -P and Ca8 -P concentrations mostly among the inorganic P fractions ,and inorganic phosphorus was increased more than or-ganic phosphorus .Low levels of organic fertilizer application (75 t·hm-2 ·a-1 ) or the combined application of inorganic and organic fertilizers was a good practice to set fertilization .%为阐明不同施肥方式对土壤磷素各组分的影响，采用蒋柏藩－顾益初无机磷分级体系，观测分析了陕西省杨陵区陈小寨村土不同施肥方式及用量对土壤中无机磷、有机磷、全磷含量变化的影响。结果表明，该土壤中无机磷占全磷的77％～90％。施用磷肥，对土壤中的无机磷和有机磷都有增加的作用（ P＜0．05），对无机磷的影响大于有机磷。各不同处理土壤无机磷组分均以 Ca －P为主，其中又以 Ca10－P占绝对优势（28．77％～63．96％）；不同施肥处理中，对作物无效态的无机磷Ca10－P、O－P比例减少，有效态的Ca2－P、Ca8－P、Al－P、Fe－P比例增加；且施用有机肥对土壤中有效态磷素的增加效果好（ P＜0．05）；在有机肥的作用下，土壤中的磷素会向无机磷的方向发生反应，尤其是活性的Ca2－P、Ca8－P的增加幅度较大。施用低量有机肥（75 t·hm－2·a－1）或无机有机肥配合施用是一个比较好的施肥方式。