Agroeconomic feasibility of diversified organic vegetable system and its relationship with the beneficial entomofauna

Abstract

Organic plant production systems that favor crop diversity tend to harbor a varied fauna involved in biological processes, reducing external inputs. Even so they may depend on animal fertilizer not available locally. This makes fertilization with only plant sources a promising alternative, but the economic-environmental return must be evaluated. The objective was to evaluate the economic viability of an organic production system of different vegetables, using strictly plant-derived fertilizers, with its profitability estimated by commercialization in the organic, conventional and local markets, and to characterize the beneficial entomofauna of this system. The study was carried out at the Intensive Vegetable Cultivation Module (MCOIH), Seropédica (RJ). The economic viability of the MCOIH was determined by the cost-benefit ratio, and the system being was monetarily viable if RB/C>1. The beneficial entomofauna was determined by capturing adult insects at georeferenced points. The highest net revenue was obtained when the vegetables were sold in the organic market. Labor and irrigation were more expensive among variable costs and fixed costs, respectively. The MCOIH harbored an entomofauna represented by 13 families that gather entomophagous insects and two families of decomposer insects. The entomophages were mostly represented by the Coccinellidae (Coleoptera) and Dolichopodidae (Diptera) families (21.06% and 65.12%, respectively). The decomposers belonged to Micropezidae and Stratiomyidae (Diptera). It is concluded that MCOIH is not viable only when the vegetables are commercialized in the conventional market and their agroecological management allows to conserve a functional beneficial fauna.