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Long‐term impacts of grazing intensity on soil carbon sequestration and selected soil properties in the arid Eastern Cape, South Africa
Author(s) -
Talore Deribe G,
Tesfamariam Eyob H,
Hassen Abubeker,
Du Toit JCO,
Klampp Katja,
JeanFrancois Soussana
Publication year - 2016
Publication title -
journal of the science of food and agriculture
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.782
H-Index - 142
eISSN - 1097-0010
pISSN - 0022-5142
DOI - 10.1002/jsfa.7302
Subject(s) - exclosure , grazing , environmental science , arid , agronomy , soil water , stocking , ecology , biology , geography , soil science , forestry
BACKGROUND Little is known about how basic soil properties respond to contrasting grazing intensities in the Karoo biome, South Africa. The aim of this study was to investigate impacts of long‐term (>75 years) grazing at 1.18 heads ha −1 (heavy; CGH ), 0.78 heads ha −1 (light; CGL ), and exclosure on selected soil properties. Soil samples were collected to a depth of 60 cm from the long‐term experimental site of Grootfontein Agricultural Development Institute, Eastern Cape. The samples were analyzed for C, N, bulk density and infiltration rate, among others. RESULTS Generally, heavy and light grazing reduced soil N storage by 27.5% and 22.6%, respectively, compared with the exclosure. Animal exclusion improved water infiltration rate and C stocks significantly ( P < 0.05), which was 0.128, 0.097, and 0.093 Mg ha −1 yr −1 for exclosure, CGL and CGH , respectively. Soil penetration resistance was higher for grazing treatments in the top 3–7 cm soil layer but for exclosure at the top 1 cm soil surface. CONCLUSION Although livestock exclusion has the potential to improve C sequestration, a sufficient resting period for 1–2 years followed by three consecutive grazing years at light stocking rate would be ideal for sustainable livestock production in this arid region of South Africa. © 2015 Society of Chemical Industry