Adubação de sistemas em pastagens hibernais com foco em sistemas de integração lavoura-pecuária no sudoeste do Paraná

Abstract

Sustainability is a topic that has been gaining a lot of strength in rural areas and this requirement must always be considered, together with profitability and greater food production, so the traditional way in which agricultural areas are invested generates some concerns. Due to the recent increase in the price of agricultural inputs and rumors of shortages, the efficiency of fertilizer use is important. A promising model that has been used in the southwest region of Paraná is livestock-labor integration, which in turn, offers several benefits to the soil, such as increased nutrient cycling and improvement of physical, chemical and biological attributes of the soil. This method can also be maximized when associated with fertilizer inversion methodologies, as long as the research generates a final set of information that supports decision-making in the field. Therefore, the objective of this study was to evaluate and quantify the advantages of inverting phosphate and potassium fertilizers, which, in the winter phase, characterize levels of potassium and phosphate fertilizers in grazed and ungrazed environments. To this end, an experiment was carried out in the municipality of Coronel Vivida-PR, with the implementation of a forage mixture, containing oats and ryegrass, combined with different strategies and doses of potassium and phosphate fertilizers, prolonged with and without grazing. The variables were evaluated: aerial biomass production, residual forage mass, forage production dynamics, nutritional value (CP,ADF and NDF), variables linked to the animal such as load, production and performance, nutritional contents in residual dry matter and chemical and physical characteristics of the soil. The experiment was conducted in a randomized block design containing 3 replications, being a bifactorial experiment, 4 × 2 in a split plot, with one of the factors being the different levels of potassium and phosphate fertilization and the other being the use or not of grazing, resulting in 8 treatments per block. It was possible to determine that it was advantageous to anticipate, totally or partially, the fertilization that would be used in soybean cultivation for winter pasture, as the fertilization systems allowed maximizing forage and animal production without generating losses for the grain crop.