套种不同牧草的果园土壤对磷的吸附与解吸特性

采用恒温培养法研究了蜜柚果园自然生草和套种不同牧草后土壤对磷的吸附和解析特性。结果表明：果园土壤对磷的等温吸附、吸附量一解吸量曲线分别与常规的Langmuir方程、二次函数方程吻合。几种牧草果园土壤的最大吸附磷量依次为：圆叶决明〉百喜草〉自然生草CK、平托花生〉宽叶雀碑；供试的5种土壤中，人工生草的果园土壤对磷的解吸率均小于自然生草。表明人工生草能改善果园土壤对磷的缓冲能力。

Characteristics of Phosphate Adsorption and Desorption of Soils in Orchards Intercropped with Different Pastures

The characteristics of phosphate adsorption and desorption in different soils in Pomelo orchard which interplanting of different forages. The results indicated that all phosphate adsorption curves and phosphate adsorption-desorption curves could be well described by Langmuir and quadratic function. The sequence of maximum phosphate adsorption among orchard soils tested were Chamaecrista rotundifolia 〉 Paspalum natatum 〉 Borreria latifolia 〉 Paspalum wetsfeteini Hackel. The maximum desorption rate was found in the soil which interplanting of Borreria latifolia among the four soils. The annual dynamics analy- sis on Phosphorus on forage residue decomposition shows that the release of phosphorus in the month with the seasons change over jagged. The maximum amount of phosphorus released was Borreria latifolia residue. In most of the month amount of phosphorus on the other three forages residue were within maxi- mum phosphate adsorption corresponding.