Water use efficiency and forage quality of Digitaria eriantha in semiarid Argentina.
Mirta B. Toribio1, Hugo E. Laborde2, Roberto E. Brevedan2, María N. Fioretti3, and Oscar A. Terenti4. (1) Departamento de Agronomia, Universidad Nacional del Sur, Altos del Palihue, Bahía Blanca, 8000, Argentina, (2) Departamento de Agronomia, Universidad Nacional del Sur y CERZOS (CONICET), Altos del Palihue, Bahía Blanca, 8000, Argentina, (3) Departamento de Agronomía, Universidad Nacional del Sur, Altos del Palihue, Bahía Blanca, 8000, Argentina, (4) INTA EEA San Luis, Villa Mercedes, 5730, Argentina
In the temperate semiarid region of Argentina unpredictable and intermittent periods of water deficit occurs almost every year. Since soil water is the most limiting factor that affects plant production in the area, the selection of species to be used there should considere its efficiency in the utilization of the available of water. Digitaria eriantha cv. Irene is one of the most promising warm-season perennial forage grasses in livestock production system of the region. An understanding of the plant response to water deficit would allow to cope with drought. The research was conducted at the Experimental Farm of the Agronomy Department in Bahía Blanca (38°44’S 62°15’W). Soil was a petrocalcic Ustipsament with a sandy loam texture and low organic matter. After cutting the dry forage, at the beginning of the growth season, 50 kg ha-1 of N was applied. Plants were cut each time they reached 0.30 m to a 0.04 m stubble height. Dry matter yield was 3.1 Mg ha-1 with a mean crude protein content of 11.5% and an in vitro dry matter digestibility of 64.2%. Water use efficiency was 5.4 kg dry matter yield ha-1 mm-1 and 0.26 kg crude protein ha-1 mm-1.