CARACTERIZAÇÃO DE COMPOSTO ORGÂNICO DE MISTURAS DE RESÍDUOS DE ORIGEM ANIMAL, VEGETAL E MINERAL SUBMETIDAS A DOSES DE INOCULANTES

Abstract

The compost is an effective method to reuse biodegradable residue, the process is mediated by microorganisms, whereby different organic materials are transformed in stable compost and nutritional quality to agricultural applications. However, the use of organic fertilizer in the large scale agriculture is limited through the action and liberation in a long time, and low nutrients concentrations to plant development. To increase the nutrients content available read in the compost, the supplementation or enrichment with nutrients and addition of microorganisms has been proposed. The objective of this study was evaluating the physicochemical quality of chicken bed organic compost, with two mix proportion, inoculant doses and changes in composting times. The experiment was installed in the experimental area of Hydraulics and Irrigation Laboratory of the Goiano Federal Institute - Rio Verde Campus. The experimental desing used was Completely Randomized Design (CRD), analyzed in factorial scheme 2 x 4 x 5 with three repetitions. The treatments consisted of 2 mixtures to the formation of compost denominated M1 (50% of plant biomass, 25% rock dust, and 20% of chicken bed) and M2 (53% of plant biomass, 27% of chicken bed 20% of rock dust), four inoculant doses (50, 100, 150 e 200% recommended dose of 150 g.m-3), and five composting times (15, 30, 45, 60 and 75 days). To the preparation of the compost was used the chicken bed (CB), plant biomass (PB) and to the enrichment, was used the rock dust (RD). After mixing and inoculation, the volume of 150L of the compost, was been conditioning in a compost reactors. The experiment was conducted for seventy five days, were evaluated the physical parameters like temperature (daily), humidity (weekly) and density (fortnightly) The chemical parameters evaluated were total Nitrogen (total N), total Phosphorus (total P), Potassium (K), Calcium (Ca), Magnesium (Mg) (fortnightly). During the composting, the temperature followed the typical standard mentioned in the literature, However, the M1 (Tmax. 52 °C) was slightly smaller than M2 (Tmax. 55°C), indicating inhibitory effects of microbial activity on the mixtures adopted in the M1 due to reduction of organic material. The estimated humidity presented intervals between 45 e 58%, representing optimal conditions for biological activity. The minimum density (dry basis) for the composting time of fifteen days to M1 and M2 was ,42 e 0,31 g.cm-3, already at the end of the last compost, at the time of composting seventy five days was 0,67 e 0,55 g.cm-3, respectively. In general, the mix 2 (M2) presented greater increment for N and P above 27,00 e 30,00%, to the K there was an increase above 27% for the composting times of 60 and 75 days. In M1, the maximum of N( 4,7g.kg-1), maximum P (1,32 g.kg-1), maximum K (8,51 g.kg-1), maximum Ca (3,15 cmolc dm·³), maximum Mg (4,36 cmolc dm·³) Will be obtained in the inoculants doses of 86,00; 84,00; 100,00; 90,00 e 90,00%, respectively, this doses has increased by about 33,75% of N, 5,54% of P, 31,07% of Ca and 24,28% of Mg. In M2, the maximum N (9,95 g.kg-1), maximum P (1,32 g.kg-1), maximum K máximo (8,82 g.kg-1), maximum Ca máximo (2,94 cmolc dm·³), maximum Mg máximo (4,36 cmolc dm·³). Was obtained in inoculants doses of 150,00; 100,00; 150,00; 162,00 e 80,00%, respectively, this doses has increased by about 13,63% of N, 12,17% of K, 16,30,07% of Ca and 34,22% de Mg in relation of recommended dose. Is recommended the use of second mixture (53% of plant biomass, 27% of chicken bed 20% of rock dust) mainly in a inoculant dose 150% (225 g.m-3).