母树林也应施肥,实验证明针叶树施肥后种子产量大增。美国一木材公司报导说在一个火烧迹地附近的林木施肥之后,种子产量增加10倍。美国林务局在几年经实验证明,橡膠树施肥后产量提高23%。这证明林木施肥后除了增加材积外还有别的好处。日本将颗粒肥料施在树根。美国俄勒冈州实验时 The mother tree should also be fertilized, the experiment proved that the coniferous fertilizer yield increased greatly after fertilization. A timber company in the US reported a 10-fold increase in seed yield after fertilizing the trees near a burned-out site. The United States Forest Service in a few years proved by experiments, rubber tree fertilizer production increased by 23%. This proves that forest fertilization has other benefits besides increasing the volume. Japan applies granular fertilizer to roots. Oregon experiment