Effects of increasing doses of corrective in the formation of sumauma (Ceiba pentandra L. Gaertn), seedlings.

Abstract

This study was carried out in a nursery at Manaus, AM, in order to evaluate the effect of increasing levels of limimg on the growth and on the absorption of nutrients of sumaúma (Ceiba pentandra L. Gaertn) seedlings. Material collected in horizon B of clay yellow oxisol was used as substratum. The used calcareous rock was a carbonate mixture of calcium and magnesium carbonate p.a., in the relation of 4:1, proportion. The treatments were increasing liming levels, 0.0; 0.5; 1.0; 2.0; 2.5; 3.0 and 5.0 ton.ha^-1. The experimental design was randomized blocks with 5 replications in a total of 35 parcels, each one with 3 plants. The substratum was fertilized with equivalents doses to 200-500-300 kg.ha^-1 of N, P₂O₅ and K₂O, respectively and 15 kg.ha^-1 of micronutrients FTE-Br12. The characteristics of growth evaluated were height, diameter of the stem, root, aerial part and total dry biomass and aerial part/root relation. It was determined the moisture contents of the aerial part, root and total. The liming affected all the growth characteristics, except the aerial part/root relation. The nutritional requirement, in the studied phase, followed the order of N>K>Ca>Mg>P>Fe>Mn>Zn>Cu. The corrective dose of 0.5 t.ha^-1 of soil or 250 g of corrective per ton of substratum was economically more advantageous and can be recommended to be used in acid subsoil of low natural fertility.