水分对硝酸磷肥中氮的扩散及其肥效的影响

INFLUENCE OF WATER CONTENT TO THE DIFFUSION AND AVAILABILITY OF NITRO-PHOSPHORUS FERTILIZER

国产硝酸磷肥含氮27%,磷13.5%。所含速效氮中硝态氮均占一半。研究麦田不同水分对硝酸磷肥中硝态氮在土壤中扩散结果显示,硝态氮在土壤中下移深度与土壤湿润峰的深度基本一致,在小麦越冬期有表聚现象。当灌水量为田间持水量时,硝态氮移动深度为40～50cm,是在主要根系活动层内,这对小麦吸收有利,不会产生氮的流失。等氮磷条件下,硝酸磷肥与磷铵加尿素在北方地区有同样肥效。

The N and P content in the native nitro-phosphorus fertilizer is 27.0% and 13.5% respactively,and one half of the available N is in nitrate form.The re- sult of research on diffusion of nitrate N in the soil showed,the depth of do- wnward movement of nitrate N in the soil profile was the same with the depth of wetting front of soil.During the winter time in the wheat field,surface accumulation of nitrate was observed.When irrigating water satisfied the field capacity,nitrate N would move to the depth of 40-50cm where the root system worked actively,thus beneficial the nutrient absorption of winter wheat,and no nitrogen would be leached. Under equal quantity conditions of N and P,the efficiency was the same for nitro-phosphorus fertilizer to NH_4H_2PO_4+(NH_2)_2CO in northern China.