Producción y calidad nutritiva del forraje de variedades de Elymus scabrifolius (Döll) J. H. Hunz y Thinopyron ponticum (Podp.) Bartworth et Dewey

Objective: To evaluate forage yield and nutritional quality of two varieties of Elymus scabrifolius (Döll) J. H. Hunz and four varieties of Thinopyron ponticum (Podp.) Bartworth et Dewey on a soil without salinity and alkalinity problems, and on an alkaline saline soil in the central semiarid region of Argentina. Materials and Methods: T. ponticum (elongated wheatgrass, AA; varieties Pucará, Hulk, Barpiro and a local variety, seed identified) and E. scabrifolius (Creole wheatgrass, AC; varieties FA UNLPam and Don Alberto INTA) were evaluated on two types of soils: without limitation by salinity or alkalinity and sodic saline soil. Two trials were conducted at the Anguil National Institute of Agricultural Technology, according to a split-plot design, the main plot being the soil type and the sub-plots, the varieties. Forage production was evaluated per cut, per year and over a three- year period. Forage nutritional quality was determined at two times of the year (autumn and spring). Results: There was no interaction between soil type and variety or differences between varieties in total accumulated forage production during the period. The total accumulated forage production during the evaluated period in the saline-alkaline soil was reduced between 40,0 and 50,0 % compared with that of the soil without salinity-alkalinity limitations. In the two varieties of E. scabrifolius, crude protein in the silvopastoral system was 38,0 %, lower with regards to the soil without limitation by salinity or alkalinity. Meanwhile, in T. ponticum, crude protein was 48,0 % lower in the sodic saline soil, this being the reason for the interaction. In both varieties of E. scabrifolius, 9,0 % more neutral detergent fiber (NDF) was observed at the autumn cutting date with respect to the spring cutting date in the saline-alkaline soil, as well as a significantly higher NDF percentage. Conclusions: The results showed the ability to implant and produce forage of both species in saline and alkaline environments. Forage nutritional quality was affected by salinity-alkalinity. In general, fiber content increased and crude protein decreased.