Abstract:

In order to provide scientific basis for nutrient management in eucalypt (Eucalyptus grandis) plantations, microelements in the plantations in Sichuan were diagnosed in sixty standard plots by correlation analysis and vector diagnosis to explore supply conditions and the interaction to forest productivity. The results were as follows: 1) there was remarkable correlation between sorption of Cu, Zn and forest productivity; 2) macro elements such as N, P and K were influenced by absorption and supply of microelements, and there were prominent interactions between microelements and macro elements or among microelements, such as synergistic effects of Cu to K, Cu to Fe and Mn to N, antagonistic effects of N to Zn, P to Zn, Ca to Zn, K to Fe, Mn to K and among Cu, Zn, Fe and Mn. 3) Cu was deficient in high altitude area and excessive in low altitude area. Zn behaved dilution except a few standard plots subjected to deficiency. Fe content in the soil changed in large-scale, and was deficient in high pH soil and excessive or antagonistic in low pH soil. Changing pattern of Mn content in the soil was the same as Fe, and it displayed excessive or antagonistic in majority of the area and deficient in minority of the area. B had sufficient supply and was diagnosed antagonistic effect.

Key words: Eucalyptus randis, microelement, nutrient diagnosis, vector diagnosis, nutrient interaction