Tightening the nitrogen cycle
Tightening the nitrogen cycle
复制标题
收紧氮循环
DOI：
--
复制
发表时间：
2004
期刊：
影响因子：
--
通讯作者：
B. Christensen
中科院分区：
文献类型：
--
作者：
B. Christensen
氮对作物的有效性是土壤质量的一个普遍重要的方面，在现代农业中，氮往往是作物生产力的直接限制。氮是植物产品营养价值的决定性因素，在农业生产的环境影响中起着关键作用。氮素管理的基本原理是通过增加矿质氮的有效性和根吸收之间的时间和空间一致性来优化引入和原生土壤氮的氮素利用效率。自然生态系统已经进化到产生高度的巧合，并保持相对紧密的氮循环。为确保具有高生产潜力的作物品种的活力所需的管理，使农业生态系统对氮素相对开放。通过将重点从单纯的生产力转移到生产力、产品质量和环境影响之间的平衡，可以重新设计农业生态系统的管理，以提高氮的利用效率。改善土壤质量的氮素方面的重要管理措施是作物顺序，包括覆盖作物，明智地使用土壤耕作，改善动物粪便，作物残留物和矿物肥料的时间和使用，以及植物生产潜力和动物饲养密度之间的可持续平衡。本章讨论了植物生产中氮循环的特点，提高氮素利用率的前提，并讨论了可以提高种植系统中氮素利用率的管理原则。
The availability of nitrogen to crop plants is a universally important aspect of soil quality, and often nitrogen represents the immediate limitation to crop productivity in modern agriculture. Nitrogen is decisive for the nutritive value of plant products and plays a key role in the environmental impact of agricultural production. The fundamental doctrine of nitrogen management is to optimise the nitrogen use efficiency of both introduced and native soil nitrogen by increasing the temporal and the spatial coincidence between availability and root uptake of mineral nitrogen. Natural ecosystems have evolved to produce a high degree of coincidence and maintain a relatively tight nitrogen cycle. The management needed to assure the vitality of crop cultivars with a high production potential cause agroecosystems to be relatively open with respect to nitrogen. By shifting the focus from sheer productivity to a balance between productivity, product quality and environmental impact, the management of agroecosystems can be redesigned to allow for a higher nitrogen use efficiency. The important management measures to improve the nitrogen aspect of soil quality are crop sequences that incorporate cover crops, judicious use of soil tillage, improved timing and use of animal manures, crop residues and mineral fertilizers, and a sustainable balance between plant production potential and animal stocking density. This chapter addresses the characteristics of nitrogen cycling in plant production, the premises upon which an improved nitrogen use has to be based, and discusses management principles that can improve nitrogen use in cropping systems.