离子交换树脂膜吸附控释肥钾素养分的动力学特征

Dynamic Characteristics of Potassium Release from Controlled Release Fertilizer by Using Ion Exchange Resin Membrane

在土柱淋溶-培养条件下,以离子交换树脂膜模拟作物根系吸收,研究了几种速度复合型控释肥钾素释放动力学特性。结果表明,树脂膜对各控释肥处理累积吸附K2O净量的大小顺序为:FT1>FT4>FT2=FT7>FT5>FT6=FT3。在试验前期,树脂膜每周吸附钾的净量与其相应的淋溶量间呈显著正相关;而在试验后期,每两周吸附量与其相应的淋溶量之间相关性不显著,树脂膜在第3周和第7周吸附养分净量较大。各处理的Richards函数M值均很接近,且大于实测值;k值范围为0.1130～0.2722,可以准确地反映出不同控释肥养分释放速率的差异;而各处理Logistic函数中M值差异较大,且均小于实测值;k值范围为0.5066～0.6006,差异不大,难以准确地反映控释肥养分释放速率。因此,Richards函数比Logistic函数能更准确地描述和预测树脂膜对不同控释肥养分释放动力学特性。

The characteristics of potassium release dynamics of multi-longevity controlled release fertilizers （CRFs） were investigated by using ion exchange resin membrane （IERM） adsorption method in a soil-column leaching experiment. The results showed that the accumulated net K20 adsorbed by IERM was in the order of FT1〉FT4〉FT2=FT7〉FT5〉FT6=FT3 among the treatments There wasa significant correlation between the net amounts of K20 adsorbed and the amount of K20 in leaching solution every week during early stages of the experiment. However, there was no significant correlation between the net amount of K20 adsorbed and K20 in leaching solution of every fortnight in late stage of the experiment. The accumulated net amount of K20 adsorbed by IERM was greater at the third and the seventh times of extraction. Results also indicated that the value of M in Richards equation was no significant difference among treatments and bigger than that measured. The value of k was in a larger range of 0.1130 to 0.2722 which was able to reflect the difference of K20 release from the CRFs accurately. Nevertheless, the value of M in Logistic equation varied among treatments and smaller than that measured. The value of k was in a narrow range of 0.5066 to 0.6006 which could hardly to reflect the difference of K20 release from the CRFs accurately. It is concluded that Richards equation is better than Logistic one to describe and forecast nutrient release dvnamic properties of the multi-longevity CRFs by using ion exchange resin membrane.