河西走廊制种田与生产田玉米需肥特点比较

河西走廊是全国最大的玉米制种基地，但存在制种玉米超量滥施化肥问题。因此，采用田间试验和室内样品分析相结合的方法，以同一组合杂交种玉米生产试验田作对照，研究了自交系玉米制种田氮、 磷、 钾需肥量及需肥特点。结果表明， 制种田玉米种子产量明显小于生产田玉米，制种田子粒产量是生产田的0.6114倍； 制种田全生育期氮、 磷、 钾吸收量均小于生产田，分别是生产田的0.738倍、 0.624倍、 0.733倍； 生产百公斤玉米种子吸收氮（N）、 磷（P2O5）、 钾（K2O）养分平均为2.653 kg、 1.115 kg和3.447 kg； N∶P2O5∶K2O比例为1∶0.42∶1.30。养分累积进程也不同，苗期养分吸收量制种田大于生产田，拔节期相近，拔节后制种田均小于生产田，养分累积量平均为生产田的63.0%~85.3%。因此，相比生产玉米，制种玉米应适当减少施肥量，并增加苗期养分供应。

Comparison on nutrient requirement characteristics of seed-producing corn and yield-producing corn in the Hexi Corridor

Hexi Corridor, Gansu Province, is the largest corn seed production base in China. Over use of chemical fertilizers in corn seed production is common in this area. The amount of nutrients for forming 100 kg economic yield and the nutrient absorption characteristics were compared between inbred line seed producing corn and yield producing corn from the same breeding line. The results show that the yield of seed producing corn is lower than that of yield producing corn, about 61.14 percent of the yield producing corn. The average uptake amounts of nitrogen, phosphorous and potassium for forming 100-kg grain in seed producing corn are 2.653 kg, 1.115 kg and 3.447 kg with the N∶P2O5∶K2O ratio of 1∶0.42∶1.30, less than those in yield producing corn, and about 73.8%, 62.4% and 73.3% of the yield producing corn, respectively. There are differences in the nutrient accumulation between seed producing corn and yield producing corn. More nutrients are absorbed in seed producing corn at the seedling stage; similar amounts to yield producing corn are absorbed at the jointing stage, and less required after the jointing stage. The total nutrient requirement in seed producing corn is 63.0%-85.3% of that in yield producing corn. Therefore, less fertilizer should be applied and more nutrients should be provided in the early growing stage in seed producing corn.