低丘红壤茶园的磷素营养及转化(英文)

试验结果表明,在低丘红壤茶园土壤中的磷主要以无机矿物磷为主,其中又以闭蓄态磷占多数,铁磷和铝磷与茶园生产能力有密切关系。茶园土壤对磷的吸附符合Langmuir吸附曲线(r>0.9)。土壤pH及质地对磷吸附有明显影响。磷肥施入茶园以后转化和被固定很快,开始以铝磷为主,以后逐步向铁磷和闭蓄态磷转化。土壤有机酸对防止磷固定有明显的影响,其影响程度是:草酸>混合酸>柠檬酸>酒石酸>苹果酸>乳酸>琥珀酸。被固定的磷及土壤原生矿物磷,在土壤游离酸,有机酸等作用下,又逐渐释放,越是高产茶园释放量越多。所以茶园土壤中的磷

Phosphorus Nutrition and Transformation in the Red Tea Soil in Low-hilly Regions

The results show that the major form of phosphate in the red tea soil in low-hilly regions is inorganic phosphate, among which O-P occupies the largest proportion; Fe-P and Al-P are closely associated with the productivity of tea garden. Phosphate adsorption by tea soil is accorded with Langmuir adsorption isotherm (r>0.9). Soil pH and texture play a marked influence on phosphate adsorption.Soluble phosphate applied to tea soil is rapidly retained and converted to Al-P at first,then gradually converted into the form of Fe-P and O-P. Soil organic acids show a marked influence on decreasing the fixation of phosphate by tea soil, effects of organic acids on decreasing phosphate fixation are described as follows: oxalic>mixed acid>citric>tartaric>malic >lactic>succinic. The phosphate is gradually released from the primary phosphate minerals and the fixed states by free acids and organic acids etc. The higher the tea yield is, the more the amounts of phosphate released from the soil are. So, the phosphorus in tea soil is situated in the condition of dynamic changes which include the form of fixation and release.