氮为植物最重要的养分之一。由于它容易淋溶、反硝化和挥发,所以也是最难处理的元素之一。新近的研究表明,在施肥与浇水的情况下,番茄吸收氮素肥料的效率低于30％(HiUs等1983)。肥料价格的增长,使人们更有效地利用肥料,并考虑到环境质量。我们已设计出了给生产者利用的一种简 Nitrogen is one of the most important nutrients in plants. It is also one of the most difficult elements to deal with because it is easily leached, denitrified and volatile. Recent studies have shown that tomatoes are less than 30% efficient at nitrogen fertilizer application (fertilization and watering) (HiUs et al 1983). Fertilizer prices have increased so that people can make more efficient use of fertilizers and take environmental quality into consideration. We have devised a simple to use for producers