Ciclagem e liberação de potássio por plantas de cobertura no milho

Abstract

The use of cover crops in agricultural systems aims to cover and protect the soil against the action of weather that can promote erosion and leaching of essential nutrients for the development of succeeding crops. On the other hand, this practice makes agricultural production more sustainable, bringing as a benefit the absorption of nutrients from the subsurface layers to the cover crops and then their release in the surface layer, positively influencing productivity. From this premise, the objective of this work was to evaluate the cycling of the nutrient potassium by cover crops and the release in the corn crop in a Cerrado-Amazon transition área, in Sinop, Mato Grosso. For the experiment, seven cover crops were used, namely: Crotalaria spectabilis, Cajanus cajan, Pennisetum glaucum, Urochloa brizantha, Mucuna aterrima, Fagopyrum esculentum and Eleusine coracana, during the 2016/2017 season. The applied design was in randomized block, in subdivided plots, in units with 4m of width x 8m of length, totaling 32m2. The sowing, fertilization and weed control procedures were carried out manually. The variables analyzed were: soil cover (TCS), dry matter (FS) and remaining nutrients from the cover crop straw. After the experiment, it was concluded that Urochloa brizantha presented the best results, being considered an excellent option for use as a cover plant.