关键词: 磷肥, 利用率, 固定, 控释肥, 土壤

Abstract: The utilization efficiency of phosphate fertilizer in the whole life of plant is only 10%—25%. By analyzing the research progress in the literatures，it indicates that the phosphorus is easily fixed in soils，including adsorption fixation and chemical reaction fixation. The amount of phosphorus fixed is determined by the content of calcium carbonate，iron oxide，aluminum oxide，clay and the initial concentration of phosphorus in soils. Most of phosphorus is fixed in adsorption fixation in early period，which lasts several hours to tens of hours. In later period，chemical reaction fixation occurs mainly and lasts a few months to a few years，which results in phosphorus unavailable to plants. The dynamics of the entire fixation period can be described by Elovich equation. For reducing the amount of phosphorus fixed，an efficient way is to reduce the concentration of phosphorus in soils. By using the fixation data from the red soil in Shenxian (in Zhejiang province，China)，together with the research data on the phosphorus uptake of cole，the release，the fixation and the plants uptake of phosphorus are quantitatively analyzed. The calculation result based on the established mathematical model indicates that the consumption amount of fertilizer can be greatly reduced and utilization efficiency can be increased by fertilizing the mixed DAP and controlled released DAP，compared with that by fertilizing DAP only.

Key words: phosphate fertilizer, utilization efficiency, fixation, controlled-release fertilizer, soil