长期不同施肥下灰漠土有机磷组分的变化

Changes of organic phosphor componentes in grey desert soil under long-term different fertilization

土壤有机磷是土壤磷素的重要供应源,也是植物吸收磷素的重要来源。对灰漠土16年长期不同施肥条件下,土壤有机磷的四种形态(活性有机磷、中活性有机磷、中稳性有机磷和高稳性有机磷)进行了测定。结果表明,不施磷肥处理(CK、N)土壤有机磷组分有下降趋势,施磷肥处理(NP、NPK和NPKM)可以提高有机磷各组分的含量,但是只有氮磷钾配合有机肥施用效果显著,有机磷总量和中活性有机磷提高了60%左右。不同施磷下灰漠土有机磷组分均以中活性有机磷为主,其占有机磷的比例为80%～90%;四种有机磷含量次序为中活性有机磷>中稳性有机磷>活性有机磷>高稳性有机磷。土壤有机磷组分中,活性和中活性有机磷含量与速效磷的相关性达极显著水平(相关系数分别为0.9403**,0.9894**;n=5),说明土壤活性有机磷和中活性有机磷有效性相对较高,是植物有效磷的主要形态。

Four forms of organic phosphor, active organic phosphor, medium active organic phosphor, medium stable organic phosphor and high stable organic phosphor in grey desert soil under long-term different fertilization for sixteen years were determined. The results indicated that contents of soil organic phosphor components decreased appulsively in soils with no phosphor fertilizer application （CK and N treatment） and increased in soils with phosphor fertilizer application （NP, NPK and NPKM）. Moreover, contents of soil organic phosphor and medium active organic phosphor were significantly increased by 60% in soil application of chemical fertilizers, Nitrogen, Phosphor, Potassium combining with organic fertilizer （NPKM）. comparing with no phosphor application. Medium active organic phosphor was the dominant component of the organic phosphor components in grey desert soil under different phosphor fertilization, which proportion was 80%-90% approximately. Sequence of contents of four soil organic phosphor in soils decreased in order as medium organic phosphor〉medium stable organic phosphor〉active organic phosphor〉high stable organic phosphor. A significant correlation between active organic phosphor and available phosphor, medium active organic phosphor and available phosphor were observed with correlation coefficient 0.9403^＊＊, 0.9894^＊＊（n=5） respectively, which showed that the availability of active organic phosphor and medium active organic phosphor was higher than other organic phosphor components. Active organic phosphor and medium active organic phosphor were principal forms of plant available phosphor.