There are three main greenhouse gass emissions from sheep-grazed rangelands in southwest Qld. They are carbon dioxide, methane and nitrous oxide. Nixtrous oxide is more cropping related due to fertilizer use and ploughing, which turns over the soil. In the grazing industry, pasture establishment and pushing over trees is a minor case of soil disturbance.
Carbon dioxide is released from the soil as soil microbes consume (digest) organic matter. The rate of release is determined by soil moisture levels and temperature. One way for rural producers to reduce the rate of these emissions is to maintain more vegetation cover to lower soil temperature.
Carbon dioxide is also released through the burning of grass and trees.
Methane is the major greenhouse gas from grazing. The major strategy for reducing methan production per kg of production is to improve the digestibility of the diet of ruminant animals. This is acheived through grazing management to improve the quality of the pasture.
