Growth Responses of Young Slash Pine (Pinus elliottii Engelm.) to N, P and K Fertilizers in Red-Yellow Soil in Jiangxi Province, China

During 1991-1995,the growth responses of young slash pine to N,P and K fertilizers and rational rate and ration of fertilizer in yellow-red soil at Fengshushan Forest Farm Jiangxi Province were studied.N fertilizer decreased the growth of slash pine,while P no only significanlty improved the increment of bottom diameter,height and crown diameter,but also caused earlier canopy closure of the stand.It also had a sustainable effect in the next two years.Slash pine had the most significant response to the treatment of 200 kg P2O5 ha^-1 ,in which tree height,bottom diameter and crown diameter(EW and SN) were increased by 22%,35%,20% and 18% i 1994,21%,25%,10% and 10% in 1995,respectively,compared to the control.Although there was no remarkable response to K fertilizer,good growth response to the application of 100 kg P2O5 plus 100 kg K2O ha^-1 existed and tree hieght ,bottom diameter and rown diameter(EW and SN ) were increased by 31%,14%,23% and 21%,respectively,in 1993 ,compared to the control.

During 1991~1995, the growth responses of young slash pine to N, P and K fertilizers and rational rate and ratio of fertilizers in yellow-red soil at Fengshushan Forest Farm, Jiangxi Province were studied. N fertilizer decreased the growth of slash pine, while P not only significantly improved the increment of bottom diameter, height and crown diameter, but also caused earlier canopy closure of the stand. It also had a sustainable effect in the next two years. Slash pine had the most significant response to the treatment of 200 kg P2O5 ha-1, in which tree height, bottom diameter and crown diameter (EW and SN) were increased by 22%, 35%, 20% and 18% in 1994, 21%, 25%, 10% and 10% in 1995, respectively, compared to the control.Although there was no remarkable response to K fertilizer, good growth response to the application of 100 kg P2O5 plus 100 kg K2O ha-1 existed and tree height, bottom diameter and crown diameter (EW and SN)were increased by 31%, 14%, 23% and 21%, respectively, in 1993, compared to the control.