Nutrient Diagnosis of Casuarina equisetifolia Seedlings Using DRIS

Using one-year-old Casuarina equisetifolia seedlings,which are the main planting species along the sandy coast of southeast China,and ternary quadratic rotary recursive fertilizer design of N,P and K,two different output types were divided based on real differences in biomass.Further,by the data of N,P and K nutrient elements contents of the seedlings,nutrition diagnosis was analyzed for C.equisetifolia.There was an obvious impact of proportioning fertilization on biomass accumulation of C.equisetifolia.The optimal solution of seedling outputs was 19.84 g per tree,and the respective quantities of fertilization were 0.329 g per tree for N,2.298 g per tree for P,and 0.154 g per tree for K.The rational scales of ratios among the nutrient elements were P/N=0.3174±0.1302, K/N=1.1010±0.506, K/P=3.5564±0.5075.Application of examples treated by ternary quadratic rotary recursive fertilizer design confirmed the diagnosing accuracy and list sequence of nutrients demanded through DRIS(Diagnosis and Recommendation Integrate System).