长期施肥对灰漠土无机磷组分的影响

以国家灰漠土土壤肥力与肥料效益长期监测站为平台,采用蒋柏藩-顾益初土壤无机磷分组方法,对23年长期定位施肥条件下、不同施肥处理土壤无机磷总量(IOP)及组分(Ca_2-P、Ca_8-P、Al-P、Fe-P、O-P、Ca_(10)-P)进行测定,以掌握长期施肥对干旱区灰漠土无机磷组分的影响规律并指导合理施肥。结果表明,长期不施肥(CK)处理土壤无机磷总量无显著变化,组分间主要发生Ca_2-P、Ca_8-P向Ca_(10)-P的转化;长期施肥(NPK、NPKM、NPKS)处理IOP极显著增加,其增加量主要为Ca_2-P、Ca_8-P、Al-P和Fe-P,其中前三者增加作用极为显著;长期施肥条件下,土壤无机磷组分中Ca_8-P转化率最高、占土壤无机磷转化总量的39%~50%,其次是Al-P、占16%~30%,再次是Ca_2-P、占10%~29%,三者合计占78%~88%,其余三种组分Fe-P、O-P、Ca_(10)-P占12%~22%。

Effect of Long-term Fertilization on Fractions of Inorganic Phosphorus in Grey Desert Soil

The contents of total inorganic phosphorus (IOP) and its fractions (Ca2-P,Ca8-P,Al-P,Fe-P,O-P,Ca10-P) were analyzed under different long-term fertilizer treatments using the method of Jiang-Gu IOP fraction based on National Grey Desert Soil Fertility and Fertilizer Efficiency Long-term Monitoring Station.The purpose of this research was to grasp the effect law of the long-term fertilization on IOP fractions in grey desert soil of arid areas and to guide the rational fertilization.The results showed that the IOP content was not significantly changed and Ca2-P and Ca8-P can be transformed to Ca10-P in CK treatment.The content of IOP fractions,especially Ca2-P,Ca8-P,Al-P and Fe-P,significantly increased in fertilizer treatments (NPK,NPKM,NPKS).Ca8-P had the highest transformation rate,accounting for 39％-50％ of total IOP fractions,followed by Al-P,accounting for 16％-30％,Ca2-P,accounting for 10％-29％.The total percentage of Ca2-P,Ca8-P and Al-P was 78％-88％,and that of Fe-P,O-P and Ca10-P accounted for 12％-22％ under the long-term fertilization condition.