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从1982～1994年，对稻作制，有机肥和地下水位三因素多水平的定位试验土壤，进行磷的恒温吸附试验，研究不同稻作制和地下水位以及施用有机肥对红壤性水稻土对磷的吸持作用的影响。结果表明，各处理土壤磷的恒温吸附曲线形状都很相似，均属于高亲和力的“L”型曲线，所有吸附资料与三个已知吸附模型的拟合程度均达极显著水平，其中以一元Langmuir模型优于Freundlich和Temkin两个模型。三种稻作制比较，稻稻冬泡土壤对磷的吸持容量明显大于稻稻冬绿和稻稻冬油土壤对磷的吸持容量;施用有机肥和提高地下水位均显著增大土壤对磷的吸持容量。除去土壤游离氧化铁和无定形氧化铁后，土壤对磷的吸持容量显著下降。土壤无定形氧化铁含量与除去无定形氧化铁后土壤对磷的吸持量的降低值和一元Langmuir方程中的Qm值分别呈显著和极显著正相关。稻作制、有机肥和地下水位对供试土壤对磷的吸持作用的影响主要是通过影响其氧化铁的活性实现的。一元Langmuir方程中的Qm值与Olsen──有效磷含量呈极显著负相关。
From 1982 to 1994, experiments were conducted on paddy soil, organic fertilizer and groundwater table with three factors and multi-level positioning test soils to study the effects of paddy and groundwater table and organic manure on red paddy soil Effect of Phosphorus Absorption. The results showed that the shape of isothermal adsorption curves of soil phosphorus were similar and belonged to high affinity “L” curve. The fitting degree of all adsorption data and three known adsorption models reached extremely significant level, The Langmuir model is better than the Freundlich and Temkin models. Compared with the three rice systems, the phosphorus uptake capacity of winter soils in rice paddy was significantly greater than that of winter and green paddy rice in paddy soils. The application of organic manure and elevation of groundwater significantly increased soil Phosphorus adsorption capacity. Removal of soil free iron oxide and amorphous iron oxide, soil phosphorus adsorption capacity decreased significantly. The content of soil amorphous iron oxide has a significant and highly significant positive correlation with the decrease of phosphorus holding capacity and the Qm value of the univariate Langmuir equation after the removal of amorphous iron oxide. The effects of paddy crop, organic manure and groundwater table on the adsorption and desorption of phosphorus by soil tested were mainly influenced by the activity of iron oxide. The Qm value in the univariate Langmuir equation is significantly negatively correlated with the Olsen-P content.