Aveia preta como planta de cobertura e planta forrageira submetida à diferentes níveis de adubação nitrogenada e potássica

Abstract

Knowing the importance of winter grasses, whether it is for soil cover or forage for animal production, it is necessary to study the different ways of management his crop, since, using the correct management it possible to generate income in a period traditionally known for losses of productivity for cattle breeders, in addition to improving the physical-chemical quality of soils due to nutrient cycling and maintenance of soil cover. The objective of this study is to compare the total forage production, residual forage, harvestable forage per cut, lodging levels and the variables involved in the dynamics of black oat production when used exclusively as soil cover and as forage in the livestock-farming integration system, subjecting both treatments to different levels of nitrogen and potassium fertilization. The experiment was installed in the experimental area of the Federal University of Technology - UTFPR, Campus Pato Branco, in the year 2016. The climate of the region is characterized as Cfa by the classification of Köppen and the soil of the area is described as red lactosoil. The experimental design adopted was randomized blocks, containing 3 blocks with 16 parcels each block. The parcels were obtained by correlating four doses of nitrogen (200, 150, 50, 0 kg N ha-1) in the form of urea (CH4N20) and four doses of potassium (80, 60, 20, 0 kg K ha-1) in the form of potassium cloride (KCl). The parcels had 21.6 m² of useful area. The parcels was divided in half, the cut of the oats as forage plant being made in part and cultivated as cover plant on the other part. When submitted to defoliation, the oat presented higher total forage yields, harvestable forage per cut and population density of tillers. In this way, it also presented lower values of light interception by the canopy, lower lodging level and remaining straw ideal for soil conservation. The proposed fertilization obtained an increase in harvestable forage yield per cut when using doses of 150 and 200 kg N ha-1 and less radiation interception in the management without nitrogen application. With the present work it is possible to recommend defoliation in black oats, even if mechanically, in exclusively agricultural areas, due to the complete change that this practice causes on the crop and all its benefits for all the system.