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玉米是我国第一大粮食作物,在国家粮食安全保障和国民经济持续发展中起着重要作用。在不增加甚至减少肥料投入情况下实现玉米单产持续增长,是我国玉米科技界亟待回答的关键科学问题和重要技术难题。为此,在我国玉米主产区,开展了生产调研、文献查阅和实践验证的综合分析。调研结果和文献分析表明,合理密植可以进一步提高玉米单产,适当减少前期氮肥用量可以显著提高肥料利用效率。东北春玉米生产实践也证明,选用耐密品种,密度提高和前期氮肥减少各30%,可增产15%,氮肥偏生产力(PFPN)可提高30%左右。可见,增密减氮有利于玉米增产和氮肥增效的协调,是实现玉米绿色增产增效的有效途径。不同玉米种植区可以通过扩行缩株种植,控前促后深施肥,因地制宜地实施增密减氮。鉴于我国玉米种植区域广泛,本文所建议的相关技术方案仍需要进一步的大面积试验验证。
Corn is the largest food crop in China and plays an important role in ensuring the national food security and the sustainable development of the national economy. The continuous increase of corn yield without increasing or even decreasing the input of fertilizer is a key scientific issue and an important technical problem that China’s corn science and technology circle needs to answer urgently. To this end, in China’s main corn producing areas, carried out a comprehensive survey of production research, literature review and practical verification. The research results and literature analysis show that reasonable density planting can further improve corn yield, and properly reduce the amount of nitrogen fertilizer in the early stage can significantly improve the fertilizer use efficiency. Northeast spring corn production practices also proved that the choice of close-tolerance varieties, increased density and pre-30% reduction in nitrogen, can increase 15%, nitrogen fertilizer partial productivity (PFPN) can be increased by about 30%. Visible, densification and nitrogen reduction is conducive to the coordinated increase of corn yield and nitrogen efficiency, is an effective way to achieve green corn yield increase. Different corn planting areas can be planted by expanding the shrinkage plant, promoting fertilization after the pre-control and implementing nitrogen and nitrogen densification according to local conditions. In view of the wide range of maize planting areas in our country, the relevant technical solutions proposed in this paper still need further large-scale experimental verification.