包膜控／缓释肥养分释放特性评价方法的研究

分别以水、土壤、砂子、土壤 +砂子和土壤 +沸石为介质 ,研究了 5种控 /缓释肥的溶 (淋 )出特征。结果表明 ,同一肥料在不同介质中的溶 (淋 )出率和溶 (淋 )出模式有很大不同 ,这主要是由不同介质的性质决定的。水中溶出率虽可以快速比较不同控 /缓释肥的溶出速率 ,但用以估测肥料在田间的实际肥效 ,则产生较大的误差。这是因为土体内强烈的物理、化学、物理化学和生物学过程必然影响到肥料中养分的释放和释放出养分在土体内的各种转化过程 ,在种植作物的情况下 ,还受植物根系吸收养分的影响。因此 ,在评价控 /缓释肥时 ,考虑土壤因子 ,把“肥—土”作为一个整体来研究 ,才能使控 /缓释肥评价更客观、更合理

Progress in evaluation method study on nutrient release characteristics of coated controlled-release fertilizer

Several media of water, soil, sand, mixture of soil and sand, and mixture of soil and zeolite were used to study the nutrient release characteristics of five types of controlledrelease fertilizers(CRFs)/slowrelease fertilizers(SRFs). The results show that there are significant differences of release pattern between water dissolution and soil leaching rate due to the different properties of the media. Considerable errors might occur when the water dissolution rate method was used to estimate the field's fertilizer effect, though the method can make quick comparisons of nutrient release rates among different CRFs/SRFs. These processes, including the strong physical, chemical, physicochemical and biological ones, as well as the process of nutrient uptake of roots under crop planting condition, had important influences on whole nutrient release course. Therefore, soil factors should be emphasized. "Fertilizer-soil" should be considered as an entirety for making evaluation of CRFs/SRFs more objective and reasonable .