THE EFFECT OF DIFFERENT N, P, K FERTILIZER LEVELS ON GROWTH OF WALNUT SAPLINGS

Two-year old walnut (Juglans regia L.) cultivars were used to study the effects of different N, P, K fertilizer levels on growth of grafted walnut saplings. The results indicated that application of N, P, K fertilizer could increase shoot length, tree height, trunk girth, root biomass and total biomass of walnut saplings, but the effect of N fertilizer on enhancing trunk girth of walnut was not significant. The best concentration of N, P, K fertilizers were all 100 mg nutrient/kg of soil.