A Massey University energy expert says the global agriculture industry needs to reduce its dependence on fossil fuels if it's to keep up with the growing world demand for food.
Ralph Sims is the lead author of a report released at the United Nations Climate Change Conference in Durban, South Africa.
Professor Sims says the food supply chain already uses almost a third of total global energy and produces more than 20% of greenhouse gases.
He says the report, produced for the UN Food and Agriculture Organisation (FAO), shows the current dependence of the food sector on fossil fuels may limit its ability to meet future food demands.
Professor Sims says the FAO projects that by 2050 the world will need 75% more food than what's currently produced because of factors such as population growth and increased protein levels.
He says the organisation is concerned that requires fossil fuels being used through the whole food supply chain, from the production on the farm to the transport, processing and cooking.
Professor Sims says food prices are currently strongly linked with gas and oil prices and there are concerns about how fluctuating food prices and increased oil prices over the next decade or two will affect food security.
He says a project undertaken with Lincoln College during the 1980s, for example, found that farmers could save 10% on fuel, 20% of their time and reduce soil damage just by operating their tractors more efficiently.
Professor Sims says other ideas are already being adopted here, including the use of precision fertilising and irrigation monitoring to make more efficient use of fertiliser and water.
He says another part of the equation is reducing waste. A third of all the food the world produces goes to waste.
Farmers could become energy producers
Professor Sims says farmers could become significant energy as well as food producers.
He says as well as adopting new technologies, that means getting smarter and more efficient with energy use on the farm as well as in food processing.
Professor Sims says farmers and processors can tap into renewable energy sources a lot more than they've done so far.
He says there's very often a lot of renewable energy that can be captured on the land and there's an opportunity to use the solar, wind, small hydro or biomass both for energy use on farms to reduce dependency on fossil fuels, but also for exporting off the farm for revenue.
Professor Sims says he has a longer term vision that many farmers will be producing food and energy, integrated together.
He says examples of that are capturing methane gas from dairy farm effluent ponds for energy use and using solar water heaters in dairy sheds.