The aim of this experiment was to evaluate the dry matter production and the content of nutrients accumulated in the aerial part of the elephant grass (Pennisetum purpureum Schum.) and alterations in the density and fertility of the soil after four years of fertilization with increasing nitrogen doses in an irrigated or non-irrigated cultivation area. For this purpose, plant and soil samples were collected from an experimental area of pasture with elephant grass in the fourth year of cultivation under increasing doses of nitrogen (100, 200, 300, and 400 kg ha-1 N, yearly in the summer) in both systems. The results showed that after four years of elephant grass cultivation, the irrigated system combined with nitrogen fertilization presented larger production of dry matter of the aerial part, which determined larger contents of the mineral elements K, Ca, and P in the plant. Also higher reduction in the content of P and increase of total organic C, K and Ca were observed in the irrigated soil in comparison to the non-irrigated system. The density was larger in the non-irrigated system.
Pasture yield; nutrient extraction; attributes of the soil; Pennisetum purpureum
