塿土是关中地区主要的农业土壤之一.随着农业生产水平的提高,作物施磷量不断增加,施入的磷肥由于有相当数量因吸附固定而在土壤中积累.关于积累的磷素在塿土中形态的转化,及其对作物的有效性,磷索在利用过程中的消长规律等方面的研究,国内尚少报导.为了合理施用磷肥,我们通过多年定位试验,对其进行了研究,现将试验情况及结果报告如下. Soil is one of the main agricultural soils in the Guanzhong area.As the level of agricultural production increases, the amount of phosphorus applied to the crop increases continuously, and the amount of phosphate fertilizer applied to the soil is accumulated in the soil due to a certain amount of adsorption and fixation In order to rationally apply the phosphate fertilizer, we have studied it through many years of location experiment, and studied on its morphological transformation, its effectiveness on the crop, the law of the growth and decline of phosphorus in the process of utilization, etc. Now the test results and the results reported below.