Effects of Varied Fertilization Strategy with N,P,K Nutrients on the Growth of Acacia mangium Saplings

With the increasing consumption of pulps and timbers in the world, many exotic tree species have been introduced to China. Among these exotic species, Acacia mangium has become a major species in plantation forestry in tropical and subtropical China, which has properties of fast growing and nitrogen fixing. This paper reports the experimental results on the fertilization strategy. Effects of varied levels of N,P,K nutrients on the growth of A. mangium saplings in a water culturing system are demonstrated. In general, phosphorus (P) is the most important factor influencing the growth of A. mangium saplings, followed by potassium (K) and nitrogen (N) respectively. The less importance of nitrogen nutrient supports the fact that roots of A. mangium are able to transfer aerial N 2 to organic nitrogen with N fixing bacteria. The optimum fertilization lever of N,P,K is at the ratio of 190(N):25(P):160(K) mg·L-1 ?