Study on indices of nutrient diagnosis of N, P, K elements in leaves of walnut
1991
Zhao Mingfan (Chinese Academy of Forestry Sciences, Beijing (China). Forestry Inst.)
The indices of nutrient diagnosis of N, P, K elements in leaves of walnut tree grown in Qi County, Shanxi Province were studied from 1985-1990. The results indicate that according to the nutrient element contents of leaves, the nutrient indices are as follows: for nitrogen, optimum content is 3.82-4.76%, latent deficient content 3.06-3.76%, severe deficient content3.06%, for potassium they are 2.59-2.61%, 1.94-2.49%,1.94% respectively, for phosphorus optimum content 0.21-0.24%. deficient content0.19%, luxurious content0.24%. Therefore, the annual optimum requirements for N, P, K each tree grown in this experimental site are 0.75 kg, 2.5 kg and 2.25 kg respectively
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