Rangeland forage biomass production and composition under different grazing regimes on a Namibian organic livestock farm.
Abstract
The extent and the mechanisms of rangeland vegetation responses to variations of stocking rate, stocking density, grazing intensity, grazing itineraries, and durations of grazing and rest events are insufficiently understood to provide practical decision support for livestock farmers grazing management. Different rangeland management and grazing strategies, among them Holistic Management TM are propagated, but lack scientific endorsement and have stimulated a vivid scientific debate. This paper reports preliminary results of a study on the impact of variations in stocking rate and stocking density on range forage biomass production and composition on the organic cattle and sheep farm Springbockvley in Namibia. Results indicate a tendency that grazing at both, higher stocking density (approx. factor 4) and increased stocking rate (between factor 1.2 and 2) resulted in lower yield depression following reduced rainfall. High density grazing appears to lead to lower accumulation of standing dead plant material and litter. The experiment is ongoing and data analysis is preliminary.