茎用莴苣施用氮磷钾肥的效应分析

采用311－A最优回归设计和{3，3}单形重心设计，设置氮磷钾肥配比和氮肥分期施用的田间试验，分别拟建了茎用莴苣氮磷钾肥施用量及氮肥分期施用比例对经济产量、施肥利润的效应函数。试验结果表明，茎用莴苣最高产量的氮、磷、钾肥施用量为N 90.92kg/hm2、P2O566.38kg/hm2和K2O 116.84kg/hm2，其最高经济产量达41.859t/hm2；最佳施肥利润的氮、磷、钾优化施肥组合为N 94.31kg/hm2、P2O5 65.97kg/hm2和K2O 116.48kg/hm2，其最佳施肥利润达26822.78元/hm2，经济产量为41.849t/hm2；较佳施氮分配比例为基肥:前期追肥:后期追肥=0.402:0.328:0.270，其对应的氮肥用量分别为N 37.79kg/hm2、30.83kg/hm2和25.38kg/hm2，期望较高的经济产量可达45.340t/hm2。

Effect and Analysis on Response of Lettuce Equilibrium Fertilization with N,P and K

A best regression design of supposed saturation and {3, 3} saturated design of single barycenter check were used to study the effects of NPK application rates and N application proportion in different growing periods on lettuce economical yield, fertilization profit. The results showed that the best NPK application of lettuce with maximum economical yield of 41.859t/hm2 was N90.92kg/hm2, P2O566.38kg/hm2 and K2O 116.84kg/hm2, the best NPK application with the best fertilization profit of 26822.78 yuan/hm2 and economical yield of 41.849t/hm2 was N94.31kg/hm2, P2O565.97kg/hm2 and K2O116.48kg/hm2, and better N application proportion of basal manure, former and latter topdressing with higher expecting economical yield of 45.340t/hm2 was 0.402:0.328:0.270,three periods N application quantities were N37.79kg/hm2, 30.83kg/hm2 and 25.38kg/hm2, respectively.