Atributos físicos de um latossolo vermelho distroférrico sob aplicação de vinhaça na cultura da cana-de-açúcar

Abstract

In the cultivation of sugar cane, the application of stillage is a common management practice. Stillage is a liquid residue produced by alcohol distilleries and has a high content of nutrients and organic matter, which makes it, when applied to the soil a fertilizer that is taken from the sugar cane field itself. Thus it is expected that stillage can also alter the physical attributes of the soil. The object of this study was to assess the physical attributes of the soil, in areas cultivated with sugar cane, after the application of stillage. The study was conducted in a red dystrophic latosol at the BUNGUE Monte Verde plant in the municipality of Ponta Pora, MS, Brasil. We used the (4x4) factorial design, evaluating 4 applications of stillage (0, 450; 600 e 750 m3 ha- 1) and their physical attributes at four depths (0,0-0,5; 0,5-0,10; 0,10-0,20 e 0,20-0,40 m), with five repetitions. The undisturbed samples were removed at 38, 75, and 111 days after application with the help of volumetric rings in between rows of the culture to determine the density, macro porosity and total porosity. Two samples with preserved structure from each parcel at each depth were used to determine the stability of the aggregates by means of DMG, DMP and dispersion index, using aggregates greater than 4.63mm. The effects of the dosages and depths on the physical attributes were verified by regression analysis. According to the results obtained, the application of up to 750 m3 ha-1 of stillage lowered the soil density and dispersion index, increasing the macro porosity, total porosity, the mean geometric diameter and the weighted mean diameter of the soil cultivated with 3 year old sugar cane. The sugar cane harvest was done by hand, with a total cycle of ten months, in general, the productivity of sugar cane increased with the dosages of stillage.