Is High Impact Grazing-Trampling a Management Option to Reduce Excess Standing Biomass in Argentinean Grasslands?
Ditmar Bernardo Kurtz1,2, Marcus Giese2, Maria Fabiana Navarro Rau3, Folkard Asch2
1National Institute of Agricultural Technology (INTA), Natural Resources, Argentina
Northern Argentinean grasslands are very productive but, due to low stocking rates, standing dead biomass accumulates every year. Fire with negative effects on the system's carbon and nitrogen balance is often used to eliminate dead biomass and therefore, alternative sustainable management options are highly requested. By implementing elements from the holistic grassland management approach, short-term, high-intensity grazing could be used as an alternative to reduce standing dead biomass thereby improving grassland productivity and green / standing dead biomass ratios. At the INTA Corrientes experimental station we designed a three times replicated 18 ha grazing- experiment. In each month of the year, a different area of 0.5 ha was subjected to three days high animal impact with 150 cattle ha-1 and traditionally grazed thereafter with 0.5 cattle ha-1. Grass re-growth was monthly sampled inside and outside moving exclosure cages. We analysed the effect of trampling and impact timing (spring, summer, autumn and winter) on accumulated green and standing dead biomass compared to biomass pools on adjacent traditionally managed grassland.
Keywords: Biomass, cattle, rangelands, vegetation dynamics
Contact Address: Ditmar Bernardo Kurtz, National Institute of Agricultural Technology (INTA), Natural Resources, Ruta 12 Km 1008 C.C. 57, 3400 Corrientes, Argentina, e-mail: kurtz.ditmarinta.gob.ar