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引 言 农业上施用化肥的优点已为人们所共知,“绿色革命”的奇迹主要是因施用化肥而产生的。林业上,因受其自身的一些因素的限制,施肥很少被研究。天然森林是那么变幻莫测,以致人们很难确定究竟施用什么肥料,用量多少才能对树木产生效益。化肥对某一树种的效益也不象在农业上那样一至两
Introduction The advantages of using chemical fertilizers in agriculture are well known. The miracle of the “green revolution” is mainly caused by the application of chemical fertilizers. For forestry, fertilization is seldom studied because of the limitations of some of its own. Natural forests are so unpredictable that it is difficult to determine exactly what fertilizers are applied and how much is needed to produce benefits for the trees. The benefits of fertilizers to one species are not as good as those in agriculture