Avaliação de compostos orgânicos provenientes de resíduos da agropecuária para o cultivo de alface (Lactuca sativa L.)

Abstract

The search for organic inputs for agricultural activities sustainably produced, offered at affordable costs to organic farmers has grown due to the demand for organic food in Brazil. The use of composted organic waste is an alternative to meeting the needs of organic fertilizer on crops. The objective of this work was to prospect and analyze agricultural residues for use in organic agriculture and, through the composting process, the effect of the application of elaborated organic fertilizers on the productivity and nutrient content of the aerial part of lettuce plants. Initially, interviews were conducted with farmers in the region of Mogi das Cruzes and Suzano identifying sources of organic waste. Chemical analysis of residues for the preparation of organic compounds were made. The obtained compounds were analyzed and evaluated as fertilizers used in basic fertilization in lettuce cultivation in an open field experiment with a randomized complete block design with 8 treatments and 3 repetitions. The treatments consisted in the use of different compounds: grass and quail manure; grass and chicken manure; grass and cattle manure; composed of mushroom and chicken manure; mushroom compound black shimeji; mushroom white shimeji compound; composed of black shimeji mushroom and quail manure; and control. The organic compounds applied in the lettuce cultivation provided higher fresh biomass production of the aerial part in relation to the control, except for the organic compound obtained exclusively from the residue of the shimeji white mushroom production. Regarding the nutrient content of lettuce, there were no significant differences for the different treatments. The use of composted organic residues for the production of organic fertilizers proved to be feasible for lettuce cultivation in organic production systems.