Desempenho da forrageira Megathyrsus maximus cv. Miaygui à adubação mineral e com cama de Compost barn: efeitos do déficit hídrico e ambiência

Abstract

Pastures are the main source of food in most cattle production systems. One of the species that is widely spread is Megathyrsus maximus because it is a grass that presents high forage production, good acceptability and animal digestibility, however, it requires soils with good fertility and is subject to seasonality in summer periods. However, synthetic fertilizers used in modern agriculture are expensive and cause serious environmental problems. The use of organic fertilizers can be an economical and sustainable alternative to be adopted, in addition to providing essential nutrients, it helps retain water in the soil, and can be a contributor in summer periods. In addition to these issues, environmental factors present a great influence on the development of forage crops, and it is essential to monitor them. Therefore, the present study aimed to characterize the cultivation environment and evaluate the productive and morphophysiological responses of Megathysus maximus cv. Miagui fertilized with Compost Barn associated with water deficit. The experiment was carried out in a double arch greenhouse, with a total area of 145.3 m2, oriented in an East-West direction and covered with 150 μm polyethylene film. The experimental design was in randomized blocks (DBC) with two sources of fertilizer (mineral and organic) and three levels of water restriction (0, 5 and 10 days). The productive, mold-physiological and physiological evaluations of the plants were carried out at the end of the experiment. Micrometeorological data were obtained using automatic and direct reading sensors in the greenhouse. For the external environment, data were obtained from an automatic station and direct reading sensor. For most of the variables, the factors acted in isolation, with interaction between the factors only for fresh mass, root dryness and stomatal conductance. Temperature, relative humidity and solar radiation showed a strong linear correlation between the environments evaluated. The organic material increased the chemical properties of the soil, as well as showing promise for the productive, mold-physiological and physiological characteristics of the forage. Environmental variables in the cultivation environment showed a strong correlation with the external environment, promoting plant development.