氮磷复（混）合肥料在潮土上的增产效应

在河北平原潮土区，就５种氮磷复（混）合肥料对小麦、玉米的增产效果进行了研究。结果表明，小麦、玉米施用氮磷复（混）合肥料后分别增产４０％～７０％和３０％～６０％。其中磷酸一铵增产效应最大，硝酸磷肥增产效应最小。５种肥料对小麦的增产作用大小为：磷酸一铵＞（尿素＋重钙）＞磷酸二铵＞（尿素＋普钙颗粒）＞硝酸磷肥；对玉米的增产作用大小为：磷酸一铵＞磷酸二铵＞（尿素＋重钙）＞（尿素＋普钙颗粒）＞硝酸磷肥。

Effects of NP Compound and Combined Fertilizers on Crop Yield in Alluvial Soil

A field plot experiment was conducted in Alluvial soil of Hebei plain and effects of five kinds of NP compound and combined fertilizers on yield of wheat and corn were studied.The results showed that the yield increments of wheat and corn were 40 %-70% and 30%-60 % respctively.The effect of monoammonium phosphate on crop yield was maximum,while phosphate nitrate minimum Effects of the five kinds of fertilizer ranged from higher to lower were monoammonium phosphate,urea combined with concentrated superphosphate,diammonium orthophosphate,urea combined with mormal superphosphate(granulated)and phosphate nitrate respectively on wheat,and monoammonium phosphate,diammonium orthopjhosphate,urea combined with normal superphosphate(granulated)and phosphate nitrate respectively on corn.