by Brenda Frick, Ph.D., P.Ag,
The Intergovernmental Panel on Climate Change has released an update on the impacts of climate change. The storm is upon us.
We can no longer speculate that maybe weather will get weird. Weird is here. Powerful weather events have increased. Polar ice is in decline. Wildfires are increasing. Global average temperature is rising.
What does this have to do with agriculture?
Much of the talk about reducing the effects of climate change focuses on energy use. In agriculture, the single largest energy use is in the production of fertilizer, and the vast majority of that goes to produce nitrogen fertilizer.
Is there another way? Of course.
Nitrogen is abundant in the air and can be captured biologically using legume green manures. Organic agriculture, which depends on green manure nitrogen, uses 50 percent less energy than agriculture based on chemical fertilizers.
It also produces less because of those green manure years, but it remains more energy efficient.
The nitrogen rich waste produced by animal agriculture becomes a pollution liability when livestock are mass-produced but can be part of the solution at lower densities.
Small, mixed farms seem to be a model of sustainability.
Pesticide production is another significant use of energy. Again, there is another way.
Organic producers have a diverse tool kit of techniques to prevent, avoid and manage weeds, insects and diseases without resorting to these chemicals.
Neil Harker at Agriculture Canada in Lacombe, Alta., has done excellent work on stacking cultural techniques, such as increasing seeding rate and growing crops in diverse rotations, as well as mechanical weed management techniques. He has found that these multiple techniques can successfully reduce weed pressures to a minimum.
Disease and insect pressures are greatest when crop diversity is low. Sound rotations can significantly reduce insect and disease levels and provide more stability in uncertain markets.
Does this mean that organics is the answer to reducing agriculture’s ecological footprint? It certainly has promise with biologically based fertility, strong and diverse weed and pest management techniques and an insistence on rotations.
Realistically, however, I’d have to say that we aren’t there yet. More emphasis is needed on reduced tillage and livestock incorporation.
Organic farmers do not substitute herbicides for tillage. Tillage remains an important part of weed control, seed bed preparation and green manure incorporation.
There is ample evidence that tillage can damage soil structure, but Diane Knight of the University of Saskatchewan has found that soil on organic farms is more resistant to these negative effects.
Perhaps this is related to the greater dependence on green manures to feed soil biology and to the higher levels of polysaccharides that soil microbes exude, which help to aggregate soil particles.
Still, reducing tillage in organic systems is important. A number of researchers, such as Steve Shirtliffe at the U of S, hope to build on the Rodale No-till Organics System de-veloped in Pennsylvania.
Rodale’s system uses crimper-rollers to establish weed suppressing mulch, into which the crop is seeded. The system relies on a longer season than we have, but Shirtliffe is finding ways to use the crimper-roller to reduce the amount of tillage in green manure termination.
Martin Entz of the University of Manitoba has found that terminating green manures with livestock rather than tillage can be effective and provide income as well as nitrogen benefits.
Manure can be a valuable source of fertility, and grazing crop land offers the benefit of capturing the nitrogen-rich urine as well as the solids, which allows livestock to “add value” to weeds, chaff and insects. A variety of livestock can provide a variety of specific functions.
The social-lifestyle aspect is perhaps the biggest source of resistance to incorporating livestock into grain farms.
Animals require daily care and don’t fit in well with busy schedules and holidays. It’s harder to find a livestock sitter than a pet sitter.
However, if we want more viable farms, perhaps this is another item we need to consider. How do we establish the needed supports to make livestock management viable as a small-scale enterprise?
Read the rest of the story via Organic farming excellent way to mitigate climate change – The Western Producer.