Produção de composto orgânico a base de casca do fruto de cupuaçuzeiro e sua utilização na formação de mudas de tucumãzeiro

Abstract

This study evaluated the composting of cupuaçu fruit rinds (Theobroma grandiflorum), combined with other organic materials [cattle manure, poultry manure, sheep manure, branches of gliricidia (Gliricidia sepium) and branches of vine-inga (Inga edulis)], and use of this compound in the formulation of substrate for formation of tucuman seedlings (Astrocaryum aculeatum). The study was conducted in two trials. The first adopted a completely randomized design, consisting of five treatments with four replications. The treatments consisted of mixing the cupuaçu fruit peel triturated with each of the five other organic materials in a 3:1 (v: v), respectively. During composting, the temperature, pH and moisture had similar evolutionary behaviors. The combinations of cupuaçu bark with manure and with branches of vine-inga had the highest initial carbon / nitrogen relationships. Inga-vine branches and cow manure, added to the cupuaçu shell had the highest yield, mass and volume of compounds produced. Poultry litter, cattle manure, and then, sheep manure, added to the cupuaçu shell, provided the organic compounds with the highest levels of nutrients. The Insect class showed greater diversity, in both the beginning and end of the process. The subclass Acari and Colembolla mesofauna were observed in greater quantity in the initial phase of the composting of different blends. The second experiment evaluated the growth of seedlings of tucumã produced using organic compounds based on the cupuaçu fruit skin combined with other organic materials, with and without application of dolomitic limestone. The experimental design was completely randomized in factorial scheme 5 (substrates) x 2 (liming), plus two additional treatments (control - no humus and limestone), with four replications. The substrates, packed in tubes of 300 cm 3 were formulated using 3:1 (v: v) and humus from different organic compounds to cupuassu fruit shell base (produced in the same experiment above). The treatments of lime were applied to the base in the ratio of 2 kg of lime per cubic meter of substrate. Different substrates containing organic compounds produced cupuaçu fruit peel bases independent of associated organic matter, or the application of dolomitic lime, favored the growth of tucumãzeiro seedlings. They allowed a greater availability of N, P and K in tucumãzeiro leaves and at the same time, reduced levels of Ca and Mg, especially the compound containing litter, which surpassed the others in the levels of P, K, Ca, and Mg. Dolomitic liming in different substrates containing different organic compounds, allowed a greater N, and Mg, availability in tucumãzeiro leaves, and the reverse situation with respect to K.