土壤磷解吸特性对菜稻轮作田间渗漏水总磷浓度的影响  

SOIL P DESORPTION CHARACTERISTICS AND THEIR EFFECTS ON TOTAL P CONCENTRATION IN PERCOLATING WATER IN FIELDS UNDER VEGETABLE-RICE ROTATION SYSTEM

作　　者：章明清[1] 李娟[1] 孔庆波[1] 

机构地区：[1]福建省农业科学院士壤肥料研究所,福州350013

出　　处：《土壤学报》2015年第1期120-127,共8页Acta Pedologica Sinica

基　　金：国际植物营养研究所合作项目(IPNI,Fujian-10)资助

摘　　要：通过四季豆-瓢瓜-早稻轮作制不同磷肥用量的3年定位田间试验,探讨土壤磷解吸特性及其解吸特征值对菜稻轮作田间渗漏水总磷浓度的影响和评价指标。结果表明,提出的解吸模型可较好地拟合土壤磷素随水土质量比变化的解吸过程,通过该模型能同时得到土壤磷可解吸量Q、土壤溶液磷浓度Cli及其缓冲系数b等解吸特征值。菜菜稻轮作的总磷浓度平均只有菜菜连作的42.6%。土壤磷可解吸量与田间渗漏水总磷浓度之间满足双速率转折点的动态特征。无论是菜菜连作还是菜菜稻轮作,Q值表征的土壤磷素淋失转折点的差异很小,平均为24.4 mg kg-1。因此,菜菜稻轮作有利于削减田间渗漏水总磷浓度,土壤磷可解吸量的双速率转折点X0可用于表征菜田磷素淋失潜力的指标之一。A 3-year stationary field experimentwas carried out to explore soil phosphorus desorption characteristics and their effects on phosphorus concentration in percolating water from fields under the garden bean （Phaseolus vulgaris） - zucchini （Lagenaria siceraria）-paddy rice rotation system, as affected by P application rate, and a model and indices for their evaluation as well. Results show that the model the authors designed fit quite wellsoil P desorption process varying with water/soil ratio. With the aid of the model it was feasible to acquire simultaneously P desorption characteristics, like amount of desorbable soil P（Q） and soil solution P concentration （C,） and its buffer coefficient （b）. The concentration of total phosphorus in the percolating water in the field under the vegetable-vegetable-rice rotation was on average only 42.6% of that in the field under vegetable-vegetable rotation. The relationship between Q and concentrationof total P in percolating water in the field fit the dynamic characteristics of ＂dual rate turning point＂. The turning point X0of soil P loss characterized by Q varied very slightly and averaged to be 24.4 mg kg-~, no matter the field was under the vegetable-vege- table-rice rotation or vegetable-vegetable rotation. It could, therefore, be concluded that the vegetabe-vegetable-paddy rice rotation system is conducive to reducing the concentration of total P in percolating water, and the dual-rate turning point X0of the amount of soil desorbable P may be used as one of the indices to characterize the potential of soil phosphorus leac- hing loss in vegetable fields.

关 键 词：土壤 解吸 菜田 轮作 渗漏水 总磷 

分 类 号：S153[农业科学—土壤学]