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在近15—20年不同组成和树龄级的林内施用无机肥的实践证明,通过施肥,首先是氮肥,是能够提高林地生产力的。如在白俄罗斯的近熟和成熟的针叶林内,每公顷施氮肥150—200公斤,年生长量提高15—30%,5—6年,每公顷可增长干材15—20m~3。但是,氮肥的利用率不高,仅占50—70%。肥效不高的主要原因是施肥方法、时间和施肥量不当,忽视了复杂的农业气象条件。因
The practice of applying inorganic fertilizers in forests with different compositions and tree ages in the past 15-20 years proves that nitrogen fertilization, first of all, through fertilization can increase the productivity of forest lands. As in the near and mature coniferous forests of Belarus, 150-200 kg of nitrogen fertilizer are applied per hectare and the annual growth rate is increased by 15-30%. For 5-6 years, the dry matter can be increased by 15-20 m3 per hectare. However, nitrogen utilization is not high, only 50-70%. The main reason for low fertilizer efficiency is fertilization method, time and amount of fertilizer is not appropriate, ignoring the complex agrometeorological conditions. because