Resumo

BETANCOURT Y, P.; FIGUEROA S, B.  e  ORTIZ S, C.. Erosión hídrica y uso de la radiación solar por especies forrajeras en la cuenca del río Coxcacoaco, México. Rev. Fac. Agron. [online]. 2005, vol.22, n.2, pp.157-169. ISSN 0378-7818.

Abstract In order to evaluate the advantages of using EPIC program (Erosion Productivity Impact Calculator) on simulation of solar radiation use, water erosion and dry matter yield of three forage species, a trial was carried out in Coxcacoaco river basin of Mexico state. Two grasses (Chloris gayana and Hilaria cenchroides) and one legume, alfalfa (Medicago sativa) were evaluated for dry matter yield in soils classified as Lithic Usthorthents. Dry matter yield was calculated in plots for 5 months and water erosion estimated by Universal Soil Loss Equation. Later simulation of solar radiation use, water erosion and dry matter yield of the same species were evaluated using EPIC program. Results showed that under conditions of this area, Rhodes grass (Chloris gayana ) was most efficient in solar radiation use with values of 28.25 and 33.68% higher to found in native grass (Hilaria cenchroides) and alfalfa (Medicago sativa), respectively. On the other hand, results showed that EPIC program tends to underestimate solar radiation use and to overestimate water erosion with this species. However, under total soil covering conditions, the program is an excellent dry matter yield simulator with this species.

Palavras-chave : EPIC; simulation; soil losses; solar radiation; grasses.