Effects Of Different Phosphorous Fertilizers On Phosphorus Loss Of Potato In Calcareous Soil

It has long been commonly recognized that the low availability of phosphorous fertilizer due to its easily fixed in soil.However,there is no clear understanding of the law of phosphorus loss in soil under the potato planting system of North China.It is generally with high input but lack of targeted high-efficiency management technology phosphorous fertilizer,resulted in a low utilization rate of phosphorous fertilizer in the main potato producing area of Inner Mongolia.Therefore,it is necessary to recognize the characteristics of phosphorus absorption and the loss of soil phosphorous fertilizer in the potato planting system,which is very important for the phosphorous fertilizer management in potato production.In this paper,three kinds of phosphorus fertilizers:monocalcium phosphate(MCP)monoammonium phosphate(MAP)and ammonium phosphate(DAP)commonly used in local potato producing areas were selected.Combined field experiment with soil column experiments,it was to explore the influence of different kinds of phosphorous fertilizer on potato phosphorus uptake,soil phosphorus fixation and leaching.The aim is to put forward the theoretical basis for the system of potato phosphorous reducing phosphorous fertilizer rate and increasing its use efficiency in potato production with northern calcareous soil.The major results of this study are as follows:(1)The application of phosphate fertilizer could significantly increase the yield of potato by increasing the tuber number per plant and tuber weight per plant,in which MAP exhibited the best effect and there were no significantly difference between MCP and DAP(2)The order of phosphorous use efficiency exhibits: MAP > MCP?DAP.The surplus of soil phosphorus is MAP lower than that of MCP and DAP.(3)Phosphorous fertilizer fixed rapidly at the beginning and then tended to steady in soil.Among three kinds of fertilizers the MAP has the lowest fixation rate.Compared to phosphorus fixation(45.95% ~ 62.51%),its leaching(0.06% ~1.26%)is negligible in the calcareous soil of potato.