Reaproveitamento de resíduos do processamento da mandioca (manipueira) : avaliação de impactos químicos e microbiológicos no solo e utilização como fertilizante

Abstract

This study evaluated the effects of the application of cassava byproduct in selected chemical and microbiological characteristics of soils of different textures. Three soil samples were collected from clay, sandy-loamy and sandy texture horizons. The areno-loamy and clay texture samples were collected from the Ap (0-0.15m) and Bw2 (0.83-1.20m) horizons of a Yellow Latossol, respectively. The sandy texture sample was collected from the top 0.15 m of a Dystrophic Quartzarenic Neossol (0-0,15m). After the chemical and physical characterization, the soils were transferred to plastic pots with capacity for one kg soil. Physical and biochemical characteristics of the cassava byproduct were accessed as well as N, P, K, Ca and Mg. The study was carried out undergreenhouse conditions at EMBRAPA cassava and Tropical Fruit. The study was set up as a completely randomized design in a 3 X 5 factorial scheme. Doses of 0, 20, 40, 80 and 160 mL of cassava byproduct were applied by kg-1 of soil, with three evaluation periods. After sampling for chemical and microbiologic analysis the plots evaluated in each period were discarded. The computer base software SISVARS was used to run the statistical analyses. The use of the cassava byproduct used as fertilizer raised the soil pH and increased the nutrient bioavailability. The sandy-loamy textured soil was the one that best responded to the residue application for most of the evaluated parameters. Conversely, most of the biological indicators evaluated in the soil did notresponded to the application of the cassava byproduct.