长期施肥下黄壤无机磷组分空间分布特征

利用土壤无机磷分级方法,研究长期施肥对黄壤中不同组分磷累积、迁移的影响。结果表明,施肥土壤全磷、有效磷、无机磷的含量均较不施肥处理有明显增加,随土层深度的加深而显著减少,施肥主要增加了Ca_2-P、Ca_8-P、Fe-P、Al-P含量,而对Ca_(10)-P、O-P含量影响较小。Ca_2-P、Ca_8-P、Fe-P、Al-P、Ca_(10)-P、O-P以表聚为主,同一土层上表现为O-PFe-PAl-P、Ca_(10)-PCa_2-PCa_8-P。不同形态的无机磷含量随土层深度呈现垂直分布规律,在0~100 cm土层中无机磷形态以O-P、Fe-P为主,且该比例随土层深度的增加而增加。因此,从长远来看,有机无机配施促使无机磷组分在土壤剖面的移动得以放缓,还不足以影响到地下水质量,更有利于黄壤区农业的可持续发展。

The Characteristic of Spatial Distribution on Inorganic Phosphorus Fractions Accumulation and Migration in Yellow Soil under Long-term Fertilization

The objective of this study was to explore the accumulation and migration of soil available phosphor-us,total phosphorus and inorganic phosphorus using different fertilizer.The data were collected in twenty years long-term fertilization experiment in upland yellow soil of Guizhou Province.Analytical methods was based on soil inor-ganic phosphorus fractions.Results indicated that compared with the control treatments (unfertilized),soil available phosphorus,total phosphorus and inorganic phosphorus fractions in M (organic fertilization),NPK (nitrogen phos-phorus and potassium fertilization)and NPKM (organic and inorganic fertilizers mixed)treatment were all in-creased significantly.The highest concentration of available phosphorus,total phosphorus and inorganic phosphorus were obtained in the topsoil,and decreased gradually with the increase of soil depth.Fertilization mainly increased the concentration of Ca2 -P,Ca8 -P,Fe-P and Al-P,while the changes of Ca 10-P,O-P were slightly.The order of con-centrations was O-P >Fe-P >Al-P、Ca 10-P >Ca2 -P >Ca8 -P.The concentrations of Ca2 -P was the lowest but with the highest nutrient availability while the concentrations of O-P was highest with the lowest nutrient availability.The regularities of distribution in inorganic phosphorus were vertical distribution and surface gathering.The main con-centrations of inorganic phosphorus were O-P,Fe-P in 0 -100 cm soil,and the proportion increased with depth of soil.Therefore,organic and inorganic fertilizers combine for application decrease the transportation of norganic phos-phorus contents in vertical direction,and not affect the groundwater quality,which could benefit to the sustainable agricultural development of yellow soil areas in the long term.