The present work was carried out in order to study: a) identification of deficiencies symptoms of N, P, K, Ca, Mg, S, and B; b) the effects the deficiency of each macronutrient and boron on the chemical composition of the plants. Young Leucaena plants were grown in pots containing pure quartz. Several times a day the plants were irrigated by percolation with nutrient solutions. The treatments were: complete solution and deficient solutions, in which each of the macronutrients or boron was omitted. Malnutrition symptoms appeared after 200 days of cultivation. Symptoms of nutrition were observed for all treatments. The concentration of the elements in the leaves of plants cultivated under normal and under deficient conditions were: N% - 3.51-2.79; P% - 0,14-0,11; K% - 2.75-1.33; Ca% - 1.11-0.41; Mg% - 0.42-0.18; S% - 0.22-0.11; B ppm - 127-25.