毛白杨人工幼林施用N、P、K效果的研究

本文研究沙地营造毛白杨人工幼林施肥的效果.结果表明:在该土壤条件下,最佳施肥总量450kg/ha,材积生长量比对照提高32.1%;最佳配比N∶P_2O_5∶K_2O=4∶3∶0.5;最佳施肥量与最佳配比二者组合的林木生长更快,材积比对照提高一倍.施肥增加了毛白杨叶子中叶绿素和N、P、K的含量,同时叶重、叶面积等也有所增加,因而促进了毛白杨生长.

STUDIES ON THE EFFECTS OF N.P.K. APPLIED TO THE YOUNG ARTIFICIAL FOREST OF POPULUS TOMENTOSA CARR.

This paper deals with the studies on the results of the fertilizer app lied to the artificial young forest of Populus tomentosa Carr. planted on sand soil. The resultS of experiments indicate that on the condition of such soil the optimum amount of fertilizer applied is 450kg/ha in terms of N.P.K. total amount, and the amount of volume increment of the forest increases by 32.1% over that of comparison; that the best proportion is N∶P_2O_5∶K_2O=4∶3∶0.5, and the amount of volume increment of the forest under such treatment increases by 28.0% over the proportion of the worst effect (N∶P_2O_5∶K=4∶6∶0.5) and that the forest planted with the combination of the optimum amount of fertilizer applied and the best proportion of N.P.K. grows faster, and the amount of volume increment of the forest under such treatment is more than double that of comparison.Fertilization has increased the contents of chlorophyl and N.P.K. in the leaves of Populus tomentosa Carr., the weight and area of the leaves, thus accelerating the growth of the plant.