Effect of calcium, sulphur and other nutrients on dry matter yield and nodulation of Leucaena leucocephala in "Cerrado" soil

Abstract

An experiment was conducted in the greenhouse at the Centro de Pesquisa Agropecuária dos Cerrados, Planaltina, DF., in which the response of (Leucaena leucocephala Lam de Wit. cv. Cunningham) to several nutrients was tested in a Dark Red Latosol (Haplustox). Levels used were 0 and 500 ppm of CaCO₃, 0 and 40 ppm of K, 0 and 15 ppm of S, 0 and 10.2 ppm of Mg, 0 and 1 ppm of Cu, 0 and 1 ppm of Zn, 0 and 0.5 ppm of B, 0 and 0.25 ppm of Na₂MoO₄. 2H₂O and a basic application of 50 ppm of P. The highest increases in dry matter yield, root weight and number and total weight of root nodules were observed when Ca and S were applied. An interaction between calcium x sulfur was also observed. Copper increased dry matter yield only in the absence of K. The application of CaCO₃ increased Ca content and reduced Mg content in plants but total Ca and Mg uptake were increased. Calcium carbonate increased soil pH from 4.3 to 5.0 while exchangeable Ca increased from 0.8 to 1.4 me/100 ml of soil. Exchangeable Mg and Al decreased from 0.6 to 0.4 me/100 ml of soil and from 0.8 to 0.47 me/100 ml of soil respectively. S application increased Ca and Mg uptake. K, Mg, Zn, Mo and B did not affect either dry matter yield or number and weight of nodules. Cu increased root weight only.