This paper had the objective of evaluating forage production, the nutritive value through crude protein, and the macro and micronutrient composition of the canarana de Paramaribo (Echinochloa polystachya H.B.K) and the canarana erecta lisa (Echinochloa pyramidalisLam) introduced in floodable areas on low and flat lands of the Guamá river, at Universidade Federal Rural da Amazônia Campus, in Belém (PA). The forage plants had been developed for three years and kept under rotative pasture, before and during the experiment. The experimental design adopted was totally randomized, in a factorial 2x4 (two species and two periods) scheme, with six repetitions. The forage samples were cut 10 cm above the soil using a 0,25 m² as the sample unit. The collection periods were: May (period1), August (period2) and November/2002 (period3) and February/2003 (period4). The aspects analyzed were: fresh mater, dry mater, nitrogen tenor, crud protein, phosphorus, potassium, sodium, calcium, magnesium, manganese, iron, zinc, copper and borum. The availability of forage decreased along with the time of pasture usage. The average tenor of PB, N, P, K e Na, Fe, Zn e Cu was higher at the rainy periods while the tenor of Ca, Mg, S, Mn e B were higher during the dry periods. The canarana erecta lisa showed lower decreasing in dry matter production and higher nutritive value than the Canarana of Paramaribo during the studied periods. However the two forage species showed a expressive reduction in production, this denotes that the pasture period of 12 days and/or the return in each 40 days constitutes an inadequate management.
Floodable land; evaluation; Echinochloa polystachya; Echinochloa pyramidalis