Ram Dalal of the Queensland-based Department of Environment and Resource Management (DERM) advocated the use of pulse crops as a potential means to cut carbon emissions.

Dr Dalal said the inclusion of legumes in farming systems reduced carbon emissions, particularly those emissions related to the manufacture and transport of nitrogen fertiliser, which was primarily derived from gas.

“Including a legume and grass phase in farming systems increases carbon sequestration, and even accounting for methane emissions from grazing animals, reduces energy use and carbon emissions,” he said.

And he said concerns over carbon-related issues would have a big impact on land use into the future.

“A major shift in land use is required to balance energy input and energy output.”

Dr Dalal said there were a range of options to increase carbon sequestration, even in the notoriously harsh Australian climate.

He said these changes would reduce nitrous oxide and atmospheric methane emissions from farming so as to reduce the gap between energy input and energy output.

“Farming has always essentially been about carbon farming,” Dr Dalal says.

He said there had been a massive depletion of soil nutrients and carbon in continuous cropping cycles in parts of Australia.

“We estimate that over a 60-year period of cereal cropping under continuous cultivation, soils of northern NSW and southern Queensland have lost more than 40 tonnes of carbon per hectare and four tonnes of nitrogen per hectare.”

Dr Dalal said energy use for cereal production exceeds energy stored in soil carbon sinks in cereal cropping farming systems.

“No-till practice has marginal effect on carbon sequestration but reduces energy use,” he said.

“Nitrogen fertiliser application generally increases carbon sequestration and grain yields but a large proportion of energy use is from manufacture and transport of nitrogen fertiliser.”