Wambiana grazing trial extension: Testing and developing grazing princip les and management guidelines for the seasonably variable tropical savannas

Summary

Rainfall variability is a major challenge to sustainable and profitable grazing management in the northern savannas. Guidelines for sustainable management do exist but their profitability and sustainability have not been tested at the paddock scale. The Wambiana grazing trial was initiated in December 1997 to test the impacts of five different grazing strategies on profitability and sustainability. 
Strategies tested were 
(i) moderate stocking (MSR) stocked at the recommended long-term carrying capacity (c. 8 ha/ Animal Equivalent (AE)), 
(ii) heavy stocking (HSR) run at about twice the long term carrying capacity (c. 4 ha/AE), 
(iii) variable stocking (VAR) with annual stocking rate adjustments based on available pasture (range: 4-12 ha/AE), 
(iv) Southern Oscillation Index -variable stocking (SOI) with stocking rates adjusted based on the SOI and available pasture (range: 4-12 ha/AE) and 
(v) a 3-paddock rotational wet season spelling system (R/Spell) with moderate-light stocking (c. 6 - 9 ha/AE). 
A full technical report on the first ten years of the trial was submitted to MLA in January 2008, followed by a further updated report in September 2009. These results form much of the grazing management section of the EDGE-GLM workshop and have been used in many other extension processes such as $avannaPlan and Stocktake. The present project was initiated to provide funding for the 2009/10 grazing season to maintain treatments, ensure data was collected and analysed and results updated.