陇单7号饲用玉米适宜种植密度及施肥量和方式初探

Primary studies on suitable planting density and fertilization for hybrid maize Longdan No.7

在大田生产条件下,研究饲用玉米(Zea mays)新品种陇单7号种植密度,施氮、施磷量及其方式对产量的影响。结果表明,陇单7号高产适宜种植密度为60 000株/hm2,产量达14 460.05 kg/hm2,密度低于或高于60 000株/hm2的处理,单产均极显著降低;施氮磷量为纯氮400 kg/hm2、P2O5300 kg/hm2的产量最高,为12 785.2kg/hm2;施氮磷方式以分底肥、拔节期和大喇叭口期3次施肥的产量最高,达13 485.8 kg/hm2,平均分2次施肥的产量次之,为13 442.0 kg/hm2,作底肥一次施入的,产量最低,仅11 261.5 kg/hm2,分3次和2次施肥方式比一次施肥方式分别增产19.75%和19.36%。因此,在本试验条件下,氮磷肥合理施用方案为纯氮400、P2O5300kg/hm2,可采用两种方式施氮磷:1)最好在播种前、拔节前期和大喇叭口期3次施肥,每次各施总量的1/3;2)也可以在播种前和大喇叭口期平均分2次施入。

Effects of planting density,nitrogen and phosphorous application rates and schedule on the grain yield of maize hybrid Longdan No.7 were studied under field conditions.The results showed that the suitable planting density was 60 000 plants/ha and the grain yield reached 14 460.05 kg/ha.The grain yield reduced significantly as planting density was higher or lower than 60 000 plants/ha.The proper nitrogen and phosphorous application rates were 400 kg/ha and 300 kg/ha respectively,and the highest yield reached 12 785.8 kg/ha under this fertilization level.The comparisons of different N and P application schedule showed that the best one was to apply N and P in tow ways,in which the highest yield(13 485.8 kg/ha) achieved as fertilization was three times,then it was 13 442.0 kg/ha as fertilization was twice,and the lowest yield was 11 261.5 kg/ha as fertilization was only one time.Therefore,the suitable fertilization schedule was to apply fertilizer(N 400 kg/ha and P2O5 300 kg/ha) at the ratio of 33.3% three times: before planting,the rest at growth stage of prophase shooting and huge bellbottom period.