黄河故道沙地杨树人工林不同间作方式的比较

The orthogonal experiment of different factors in 6\|year\|old poplar stands,including intercropping crops,application rate of fertilizer,and planting density of forest tree etc.,was carried out in the sandland of the Yellow River original course.The results indicated that doing intercropping,enlarging the row spacing and prolonging the time of intercropping were the effective ways by which the needs of forest tree for nutrients could be applied,and the level of forest land productivity could be increased.Meanwhile,the optimum intercropping way of poplar plantations at different ages was gound,which was useful for the site of tne present experiment.