氮磷复(混)合肥料的氮素肥效

研究复合肥料中氮素的利用率、残留率、损失率、肥效和残效表明:在作基肥施用的条件下,复(混)肥料对春小麦籽粒的增产效果相同。春麦对肥料氮素的吸收利用取决于氮素的形态,尿素磷铵中的铵态氮利用率为35.0％,硝酸磷铵普钙中的铵态氮为31.4％,尿素磷铵中的尿素氮为28.1％,硝酸磷铵普钙中的硝态氮为24.8％。硝酸磷铵普钙中的硝态氮具有最高的土壤残留率(48.9％),尿素磷铵中的铵氮损失率最低(22.7％)。不同复(混)合肥均有明显残效,水稻的籽粒产量都高于对照,不同复(混)合肥之间差异不明显。水稻对残留氮的利用率不同复(混)合肥之间的差异也不明显。

EFFICIENCY OF NITROGEN IN NP COMPOUND ( MIXED ) FERTILIZERS

Pot experiments with spring wheat (Triticum aesiivum L.) and rice (Oryza sativa L.) were designed to study the utilization rate of different forms of 15N labelled components of fertilizers and the efficiency of N residual in soil.Results showed that:1.Three kinds of fertilizers ( nitrophosphate, urea + MAP, and urea + superphosphate)gave the same effect on the yields of wheat when they were used as a basal fertilizer.2.The utilization rate of fertilizer nitrogen by the shoot of wheat depends on the nitrogen form rather than type and composition of fertilizer.The utilization rates are 35.0% for NH4+ in urea + MAP; 31.4% for NH4+ in nitrophosphate; 28.1% for urea N in urea + MAP; 24.8% for NO3- in nitrophosphate.Among the three forms, the NO3- of nitrophosphate was of the highest soil residual rate ( 48.9% ) and the nitrogen in NH4H2PO4 had the lowest loss rate ( 22.7% ) .3.All types of tested fertilizers applied to spring wheat as basal nutrient were of equal effect on grain yield of the subsequently planted rice.7.2%-8.9% of 15N labelled components of fertilizers applied to spring wheat as basal nutrient were utilized by rice plants ( grain+straw) . No significant difference was found among all treatments.