Nurtient Omission Experiment of Eucalyptus grandis Seedlings in Six Forest Soil Types

In greenhouse,13 treatments were conducted.The study on nutrient deficiency treatments of Eucalyptus grandis seedlings showed that more than one nutrient limited growth of heights,diameter and biomass production of E.grandis seedlings in each of the tropical soils that were examined,and biomass is most sensitive in the three indexes.Nutrients that limited seedling growth on each soiI type were:P and Ca of Galmara soil;P,N and S of Tyson soil;P and Ca of Pigin soil;P,N,S,Zn and B of Kirrima soil;P,N,K and S of Bulgun soil;P,N,K,S,Zn and Mo of Hull soil.When these nutrients that mentioned above were omission from the complete nutrient formulation(COM)in the relative soil types,biomass above ground(Da) of seedlings were reduced by 24%～98%,comparing with Da values of COM treatment.A simple guide to diagnosis of foliar symptoms of deficiencies of 5 major elements(N,P,K,S and Ca) has been prepared.