Changes in Olsen P in Relation to P Balance in Contrasting Agricultural Soils

作     者：Isabel DIAZ Jose TORRENT 

作者机构：Departamento de Ingeniería Aeroespacial y Mecánica de FluidosEscuela Tdcnica Superior de Ingeniería Agronómica(ETSIA)Universidad de SevillaCtra de Utrera km 141013 Sevilla(Spain) Departamento de AgronomiaUniversidad de CordobaEdificio C4Campus de Rabanales14071 Cordoba(Spain) 

出 版 物：《Pedosphere》 (土壤圈（英文版）)

年 卷 期：2016年第26卷第5期

页      面：636-642页

核心收录：

学科分类：09[农学] 0903[农学-农业资源与环境] 090301[农学-土壤学] 

基　　金：funded by the former Spanish Ministry of Science and Innovation(No.AGL201129893-C02-02) the European Regional Development Fund 

主　　题：calcareous soils conversion factor inorganic P noncalcareous soils organic P pseudototal P soil property soil test P 

摘      要：Maintaining soil phosphorus （P） at adequate levels for plant growth requires assessing how the long-term P balance （viz., the difference between P inputs and outputs） results in changes in soil test P. The hypothesis that routinely measured soil properties can help predict the conversion factor of P balance into Olsen P was tested at 39 sites in agricultural areas of the Mediterranean region in Spair~. A set of soil samples from each site was analyzed for Olsen P, inorganic P （P extracted using 0.5 mol L-1 H2SO4）, pseudototal P （P extracted using 0.5 mol L-1 H2SO4 following ignition at 550 ~C）, and organic P （the difference between pseudototal P and inorganic P）. Organic and Olsen P were uncorrelated in most of the 39 soil sets, which suggests that organic P content changed little with P inputs and outputs. The slopes of the regression lines of Olsen P against pseudototal and inorganic P, which were used as two different measures of the conversion factor, ranged widely （from 0.03 to 0.25 approximately）, with their average values （about 0.10） being similar to those found in long-term experiments conducted in temperate areas. Neither conversion factor was significantly correlated with any routinely measured soil property; however, the conversion factor for inorganic P was significantly lower for calcareous soils than for noncalcareous soils. Our negative results suggest the need to isolate the influence of soil properties from that of management systems and environmental factors relating to P dynamics in future studies.