The amazonian capim-acu is less nitrogen dependent than antelope grass to produce leaf dry matter

Abstract

The MaranhAo floodplain is dominated by native grasses like capim-acu (Paspalum plicatulum, Mich.). Due to scarce information on nutrient demands of native species, farmers are replacing native pastures by exotic and potentially invasive species such as antelope grass (Echinochloa pyramidalis, Lam). The aim of this study was to compare the growth of capim-acu and antelope grass, under varying N and K doses, to better understand the potential of capim-acu to be used as forage. The experiment was carried out in pots, consisting of a 2 x 5 x 2 factorial scheme (2 species x 5 N doses x 2 K doses) with four repetitions, in a completely randomized design. The N doses of 0, 50, 100, 150 and 200 mg dm(-3) were combined with 10 and 30 mg dm(-3) K2O. The capim-acu produces higher leaf to stem ratio aboveground by using lower nitrogen and potassium doses than antelope grass. Leaf, stalk, and total dry matter production of both studied species do not respond to potassium doses.