Balanço de potássio no solo sob uso de cama de aves durante 11 anos

Abstract

Potassium (K) is one of the main macronutrients required by corn (Zea mays) to obtain high levels of production. Broiler litter is an alternative to be used as fertilizer, which can reduce its production cost and provide large amounts of K for plant absorption, however in some situations, excessive application of this compound may deposit very high levels of K. levels of potassium and other nutrients in the soil, indicating the possibility of a loss of nutrients and, consequently, environmental contamination. The objective of this work was to evaluate the potassium balance in the soil with the application of doses of chicken litter, broadcast and before corn cultivation compared to the use of mineral fertilizer in long-term work. The experiment was conducted at the Federal Technological University of Paraná on the Dois Vizinhos Campus. The design used was a randomized block design with three replications for each treatment, which were, on the annual average, 0, 3, 6 and 9 t ha-1 of poultry litter and treatment with three replications of mineral fertilization with a biannual application of 100 kg ha-1 of P2O5, 100 kg ha-1 of K2O, where both were broadcast after corn sowing and cover application at the V5 stage of corn at a dose of 200 kg ha-1 of N. Through this work, we observed that dosages above 3 tons of poultry litter cause accumulation of K in the soil, favoring nutrient loss through leaching, since K levels increased significantly at greater depths of the soil. The yield of corn grains, referring to the dosage of 9 t ha-1 of bed, provided a production equal to the dosage with mineral fertilizer. Greater efficiency (28.5%) was obtained with the application of mineral fertilizer compared to poultry litter dosages, and the greater the amount of poultry litter applied, the lower the proportion of K exported via grain by the crop to K applied. The dose of poultry litter that provided the greatest accumulation and addition of K to the soil was 9 t ha-1. Doses of up to 3 t ha-1 are suggested as a way to guarantee K nutrition for an annual grain cultivation cycle.