Estratégias de produção in situ de biomassa de leguminosas arbustivas e arbórea para confecção de compostos fermentados empregados na fertilização de cenoura e alface consorciadas em cultivo orgânico

Abstract

The general objective proposed for this dissertation was to optimize the biomass production of shrubs and trees for use as raw materials in the manufacture of fermented compounds. The dissertation was structured in three stages. The first stage aimed to evaluate the agronomic performance of pigeon pea (Cajanus cajan) - GU and tefrósia (Tephrosia sinapou) - TS in monoculture or intercropped with corn in spatial arrangements under organic management. The treatments consisted of pigeon pea in monoculture; monoculture Tephrosia; guandu intercropped with corn sown in the same furrow; tefrósia intercropped with maize sown in the same furrow; guandu intercropped with corn sown between the lines; tefrósia intercropped with maize sown between the lines; and corn in monoculture. The cultivation of legumes intercropped with corn did not affect the agronomic characteristics of this cereal. In turn, corn competed with these two legumes when the consortia were compared to the respective pigeon pea or Tephrosia monocultures. The levels of N in the aerial part of pigeon pea and Tephrosia were not influenced by the presence of intercropped corn regardless of the spatial arrangement of cultivation. However, the total accumulated amounts of N in the aerial part of the legumes were lower in the consortium, when compared to the respective monocultures. The second stage aimed to evaluate the chemical characteristics and the N supply capacity of fermented compounds, made using mixtures containing GU, TS or leucena (Leucaena leucocephala) - LE leaves. The treatments, totaling 16, were arranged in a randomized block design being distributed in a 3 x 4 + 4 factorial arrangement. The sources of variation were formed from three residues of low C / N ratio (GU, TS LE) and four formulations. Thus, the mixtures were formed in the following proportions: 35% + 55%, 30% + 60%, 20% + 70% and 15% + 75%, respectively, of FT + FG or TS or LE, plus four treatments controls, whose mixtures contained 60% wheat bran-FT and / or 40% castor-bran-FM, GU, TS or LE. Mixtures in which the proportions reached 90%, 10% of sugarcane bagasse-BC were included. Formulations of fermented compounds made with the addition of leaves from the legumes Cajanus cajan, Tephrosia sinapou and Leucaena leucocephala present characteristics favorable to their use as organic fertilizers. The fermented compost made from the mixture of wheat bran and leaves of Tephrosia sinapou (60: 40% w / w) has agronomic efficiency in the supply of N compatible to castor bran. The third stage aimed to evaluate the agronomic efficiency of the organic cultivation of the consortium of carrots and romaine lettuce, fertilized with the fermented compounds that presented better chemical characteristics and the better capacity of supplying N, except for the compound formed by the mixture of 60FT + 40FM, which was replaced by castor meal, plus a control treatment without fertilization. Meal from leguminous leaves of Cajanus cajan, Tephrosia sinapou and Leucaena leucocephala have characteristics that allow to completely replace castor bean bran in the manufacture of fermented compounds used in the fertilization of carrot and romaine lettuce intercropped and submitted to organic management, providing similar yields achieved with the application of castor bran “in natura”. The carrot fertilization, subjected to organic management and intercropped with lettuce, using fermented compounds whose composition makes use of Leucaena leucocephala or Tephrosia synapou leaves, replacing wholly castor bran and half the quantity of wheat bran, in the presence of 10% sugar cane bagasse, provides productive performance of roots of this vegetable similar to that achieved with castor bran “in natura”.