Resistência mecânica do solo a penetração e rendimento de milho em sistema integração milho-bovinos de corte

Abstract

There is an increase on food demand and to support this demand, land use has been intensified, bringing up several discussions regarding sustainable agriculture. Crop-livestock system is used in this context aiming to maximize natural resources useand inputs, with less impact on the environment and better profit return.Although, the introduction of animals in theseagricultural areas has brought up many paradigms about soil degradation and increased bulk density, affecting the production system. Of course, by managing animal stocking rate, these effects can avoid. This work aimed to evaluate Black oat yield managed with rotational grazing. Moreover, corn yield grown after animal grazing period was evaluated receiving increasing doses of nitrogen.This study was carried out at São Marcos Farm in partnership with UTFPR, Dois Vizinhos. This study was divided into two phases.The first phase aimed to evaluate the effects of grazingover black oat yield during winter. The second phase, during the summer, consisted of the cultivation of corn receiving doses of nitrogen (0, 100, 200, 300 kg ha-1), seeded in areas with and without grazing. Animal live weight gain, corn yield and soil resistance to penetration was evaluated. Grazing did not affect pasture production. Animal gain also was not affected by lower forage mass grazing black oat at the end of its cycle.Corn yield showed a linear increase as nitrogen level increased with better result at the grazed areas. Trampling effects over soilresistance to penetration occurs mainly at the top soil layer (0 20 cm). Corn crop improved soil physics traits and eliminated soil resistance to root development on the top soil layers.