Uso de resíduos do caulim e da vermiculita como subs-trato para produção de mudas de mamoeiro.

Abstract

The extraction and processing of kaolin causes enormous environmental impacts, since on av-erage 70% of the raw material used in the processing is discarded in the environment, in the form of waste, the use of this residue in agricultural production, mainly in the production of seedlings, would make a supply to reduce the pollution generated by this waste. In this work, the objective is to evaluate the potential of the residue of the mineral exploitation of kaolin and vermiculite as a component of a substrate for the production of papaya seedlings. Two experi-ments were carried out in a greenhouse, one of which was carried out with residue of ca. lim and another with vermiculite residue. In both experiments, the experimental design used was completely randomized, with treatments corresponding to five proportions of the mining resi-dues with four replications totaling 20 experimental plots. The treatments were established in T1 containing 0% of mining residue + 75% of soil + 25% of bovine manure, in T2 containing 10% of mining residue + 65% of soil + 25% of bovine manure, in T3 containing 20 % of mining residue + 55% of soil + 25% of bovine manure, in T4 containing 30% of mining residue + 45% of soil + 25% of bovine manure and in T5 containing 40% of mining residue + 35% of soil + 25% of bovine manure. Each experimental plot consisted of 8 plants, 160 seedlings in each experiment. Among the variables evaluated, only the number of leaves per plant and the number of plants per plot were not influenced by the proportions of the residues tested. The values of height and diameter of the collection obtained in the treatments were within the 15 - 30 cm range in the treatment with Kaolin and with Vermiculite, 15 - 27 cm, with diameters (6 - 7 mm), however, there were no statistical differences between them treatments. It was also observed that of all parts of the plant that were benefited with kaolin, the most ideal proportion was 30%. In relation to the nutrients of the residues that favored the development of the plants were cal-cium and pH. It is also verified that the implantation of kaolin and vermiculite in the soil is an alternative so that both residues are not deposited in the environment, causing degradation.