The Effect of Fertilization on the Young Loblolly Pine Plantation in Polluted Region

From 1990～1992,experiment on the effect of nutrition adjustment on the young loblolly pine plantation in polluted region has been conducted in Sichuan Province through fertilization treatment.The size of the experimental plot is around 6 hm2 and the area for observation 1.8hm2.The result showed that the effects of different treatments on the growth height,DBH and ground diameter of the trees were very significant(α=0.01),Fertilizer containing Ca,P,N was the best one among the 6 treatments.After 3 years,the height growth of the best treatment increased by 80%～166% than that of the control.After fertilization,the symptom of pollution damage lessened; yellow needles reduced by 13%～60%;fallen needles reduced by 25%～77% in May of the following year.It showed that using nutrition adjustment to reduce the pollution damage is effective.