Utilização da água do processamento dos grãos de café: potássio no solo, na planta e produção de capim Angola

Abstract

The wet post-harvest processing generates water from coffee processing (APC), which contains potassium (K), becoming, if badly disposed, an environmental concern, given the risk of potassium leaching. Fertigation is an alternative to APC disposal. Considering that the application of the APC can promote changes in soil K levels, as well as cause a change in the production of Brachiariamutica dry mass (angola grass), without nutritional imbalance of the plant, the objective of this study was to evaluate the available levels of K in the profile of a Fluovian Neosol in the plant and the production of dry mass of angola grass, due to the application of different APC doses. A survey was carried out in a rural property located in Ibatiba county, ES, and APC was collected i n its coffee processing unit. Based on the K content analyzes of the filtered APC, it was established the APC doses to be applied to the soil, according to the treatment. The experiment was set up in an area with implanted pasture, and four replications were made. The plots received five treatments: APC doses 0, 57, 114, 171 and 228 m³ / ha, calculated so that a dose of 114 m³ / ha raised the K content to 5% in the CTC (T) of the soil. Soil samples were collected at 45 and 90 days after APC application at depths of 0 to 20 cm, 20 to 40 cm, 40 to 60 cm and 60 to 80 cm, being collected, in the same period, samples for leaf analysis and dry mass. APC application, up to the dose of 114 m³ / ha, promoted increase of K in the soil at depth 0-20 cm, occurring its increase in the lower layers only at the higher dosages. There was no difference in biomass production and nutrient content in the plant. APC fertigation uses at a dose of 114 m³ / ha was effective in replacing K in the soil surface layer, maintaining the 5% content of CTCpH7.