Factorial analysis of the effect of sugarbeet vinasses on agroecological indices in horticultural field

Abstract

The impact on soil of applying sugarbeet vinasses (V) was analyzed through a field experiment in horticulture greenhouse, arranged in a 23 factorial design. Two levels of three independent variables —application of V, use of polyethylene cover (PC) on the soil, and soil depth (D)— on various dependent variables were studied. Vinasses favoured crop yield and reduced the number of Meloidogyne incognita juveniles in soil. The concentrations of N, P and K increased with the interaction VõD, with PC also increasing N concentration. The amounts of humic acids and humin decreased with D; fulvic acid concentration increased with V, but decreased with the interaction VõPC. Soil physical factors were improved mainly with D and V. Aromaticity of humic acid-like fractions increased with V. In general, V showed significant effects mainly on the topsoil, suggesting low leaching risks. The results indicate that the levels of the independent factors improving a group of variables were not the same that those contributing to another group. Therefore, their best combination should be determined for each scenario to achieve optimum agroecological performance.