Going nuts over energy options

Aaron Edmonds

WA graingrower and 2002 Nuffield Scholar Aaron Edmonds (left) reflects on the challenges and opportunities presented by rising oil prices, plus a home-grown energy option for Australian farms.

The single biggest worry in the world of agricultural production is that our farming systems have evolved with the assumption that oil will always be cheap. Vast amounts of energy are required to produce nitrogenous fertiliser and pesticides. It takes the energy from roughly one litre of oil to produce one kilogram of urea.

One must therefore appreciate that rises in the cost of energy will lead directly to inflationary pressures on the price of nitrogenous fertilisers.

This will impact tremendously on the profitability of nitrogen-hungry crops such as wheat and canola. Our most profitable crops are in danger of becoming our least profitable.

The three major areas in which agriculture has unacceptable exposure to rising oil prices are in fertilisers, herbicides/pesticides and diesel.

The challenge and opportunity for agriculture is to manage all three areas.

Some would argue that nitrogen based fertilisers are not needed in legume-based systems where nitrogen is biologically produced.

The lupin in particular is the most widely adapted legume in Australia and breeding work is urgently needed to add value to this grain. Ultimately lupins will need higher oil content because all our current oilseed crops have high nitrogen requirements.

Australia does not have a legume that is also an oilseed, so it is worth bearing in mind that our greatest risk from rising oil prices could also be our greatest opportunity.

Herbicides and pesticides are produced through complex and energy expensive industrial processes. As our crops have been bred to focus almost completely on yield and not on traits that allow them to tolerate and compete with pests and weeds, the grains industry has ensured productivity is linked to high chemical inputs.

This effectively means that the energy required for pest and disease control in the plant is ultimately sourced from fossil fuels.

However, the wild plants and wild relatives of our commercialised crops have developed unique means to survive pests and compete with other species. This is where the area of transgenics offers agriculture the ability to re-arm our crops with the necessary genetics to begin doing the work our herbicides and pesticides currently do.

Diesel use is a fact of life in food production, but there are still more energy/fuel savings that industry can strive to achieve.

All agricultural grain crops are annuals and so require replanting each year. But what if they were perennial and effectively allowed producers to get two, three or many more harvests from the one establishment?

Examples of successful work in this area are in Alberta in Canada, where the world"s first perennial cereal rye is set to be released this coming season.

Perennials allow for gains in nitrogen use efficiencies and also increased water use efficiencies and effectively buffer the rough edges out of extreme seasons.

They can also out-compete annual weeds and have higher tolerances to pests as system ecologies evolve.

So, we have established that we need to be largely legume-based, perennial based, produce a protein-rich oilseed and not be transgenically altered (given the political, rather than scientific, stance taken by state governments).

Could one answer lie with an Australian native? From work we have already done, the answer is a clear yes.

Australian sandalwood is a unique native tree crop highly adapted to Australian conditions. The tree produces nuts that are high in oil (60 percent) and protein (18 percent) with the kernel oil being largely the healthy monounsaturated oil (55 percent). It requires no nitrogen fertiliser and has the potential to become an important, valuable oilseed.

Trials for this dryland tree crop are under way at our property east of Calingiri in the WA wheatbelt. We have been selecting, from bought seed, for large seeds and now have varieties whose nuts are as big as a 20-cent piece. Four-year-old trees are yielding well in excess of 1kg of nuts per tree, with this yield set to increase as the trees grow.

A planting density of 600 trees/hectare in a 350mm rainfall zone, could lead to a per hectare yield of about 600kg - and the trees would be expected to produce for at least 100 years.

The major energy cost in this system is weed control and harvesting; still significantly well below that of wheat production.

Plantings will continue because we have realised we are quite probably becoming the first broadacre grain producers to achieve significant energy efficiencies in food production.

Poorer soil types such as sands over gravel and areas prone to frost are being targeted first. These are the areas where energy investments in the form of fertiliser and herbicides are generally the highest.

Oilseed crops are essential to the future farm landscape, allowing farmers to profit from the energy market and also to achieve energy self-sufficiency in food production. Australian society, unbeknown to them, will benefit greatly from this realisation should we eventually get there.

Research priorities in the Australian grains industry need to sharply refocus back on to legumes - more specifically, though, on leguminous oilseeds, for it is these crops that will be the most important going ahead into uncertain times.

For more information: Aaron Edmonds, earthfarm2000@hotmail.com