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

Abstract: 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.