Cow-Calf Production on Perennial Pastures in the Central Semi-Arid Region of Argentina

In cow-calf production systems in San Luis, the annual crops are heavily used (eastern region) or the natural pastures are over-used (western region). Both cases constitute unsustainable systems. In the present study, the possibility of structuring an efficient and stable stockbreeding agroecosystem based exclusively on perennial summer grasses was tested. The objectives were: 1) to test a cow-calf production system based on perennial pastures: Digitaria (Digitaria eriantha Steudel subsp. eriantha cv Irene), without protein supplement during winter, and 2) to determine the physical and economical efficiency of the production system and sustainability of such indicators in the short-term (6 years of performance)

Dry matter production and nutritive value of forage of Digitaria eriantha cv. Irene in two locations oft be central semi-arid region of Argentina

The aim of this experiment was to compare dry matter (DM) production rates and nutritive value of a warm-season grass, Digitaria erisntha ev. Irene, in two locations of Central Argentina, Santa Rosa (SR) and Villa Mercedes (VM). The plants were established in two identical groups of plots, within a randomized block design DM rates were calculated from serial, out of phase clippings, and in vitro dry matter digestibility (IVDMD) and crude protein (CP) content analyzed on subsamples. The study lasted for three consecutive growing seasons. Results showed that DM production rates were generally higher (P<0.05) in SR than in VM, but IVDMD and CP content showed no clear trends between both locations. DM production tended to lower from year 1 to 3, related to processes of N depletion from soils (VM) and diminishing rainfall (SR). It is concluded that D. eriantha is a very promising warm-season grass to Central Argentina. Data of nutritive value obtained in one location can be used in others, but results of DM production rates should be taken under the conditions where they will be used.Resúmenes de Trabajos presentados en otras publicaciones (por docentes de la UNLPam.)  Publicado en Proceedings of the XVIII international grassland congress. Forage and Management, Session 22: 101-102, 1997

Conferencia: Manejo de pastizales. simulación de alternativa de uso de un pastizal de Piptochaetium napostaense y Poa ligularis

Manejo de pastizales. simulación de alternativa de uso de un pastizal de Piptochaetium napostaense y Poa ligulari

DCR Forest Cutting Plan : Watershed, Ware River : Town of Oakham and Rutland, Rt 148 and 122

Se determinó el efecto de la defoliación sobre rendimientos, composición y proteína bruta (PB) de Bothriochloa sp. (cv. Dahl, Spar, Plains) y Bouteloua curtipendula (cv. Vaughn). Frecuencias de defoliación de 28, 35 y 42 días (Tl, T2 y T3) y corte único (T4) y participantes se dispusieron en un diseño de parcelas divididas. Se determinaron: acumulación de MS de planta entera (RPE) y lámina (RF) -kg.ha-1.año-1, PB en F (%), rendimiento de PB (RPB, kg.ha-1.año-1) y valores medios de tasa de acumulación (tc, kg.ha-1.dia-1). Los datos se analizaron por el procedimiento GLM (SAS) y contraste de medias con Tukey (p<0,05). Valores acumulados totales: Dahl tuvo RF superiores a los restantes participantes; entre tratamientos, con excepción de Dahl los valores inferiores de RF, PB y RPB correspondieron a T4. Valores discriminados por corte: en T1, T2 y T3 las tc más elevadas correspondieron al corte 2. El corte 1 tuvo menor PB, por senectud de parte del F. Se destacó Dahl por su RF, con defoliaciones cada 28, 35 o 42 dfas, que permiten la cosecha de F con al menos 8 % de PB