Spatio-temporal status of vegetation, soil and cattle serum minerals in degraded communal rangelands of the Eastern Cape, South Africa : implications for livestock sustainability and management interventions

Abstract

In this study, we examined forage, soil and cattle serum mineral status, and their relationships in severely (SD) and less severely (LSD) degraded rangelands, South Africa. Such evidence is essential to inform rangeland policies and interventions. In each rangeland, three villages were identified, and sites near, at intermediate and far distance from homesteads were selected. Soil from LSD had generally greater macro and microelement levels than soil from SD rangelands. Soil elements (i.e. N, P, Mg and Cu) displayed variations at local scale (between villages or distance points from homestead) depending on degradation condition. Degradation level significantly influenced the local distribution of grasses between the distance points from the homestead (Themeda triandra Forssk., Aristida congesta Roem. & Schult.) and between villages [Digitaria eriantha Steud., Eragrostis curvula (Schrad.) Nees, T. triandra]. Forage biomass was low (range: 45–223 kg ha−1) in both degraded conditions. During the dry periods, cattle grazing SD rangelands had most serum minerals below a critical level, but pastures showed Cu and N deficiencies only. We conclude that the low forage yield may limit animal mineral intake. On the other hand, the great abundance of grasses with high forage values (60–76%) indicates that degraded areas may be regenerated. In SD rangelands, complete mineral supplementation is recommended during the dry period.