As I write this, the skies have opened up and the dirt roads are running with muddy water. I am thankful that we have little farmland that is bare soil, or the erosion would be phenomenal.
Our healthier soils can absorb a lot of rainwater and spring run off from melting snow. But we must manage for that health.
Good soil has small clumps (aggregations) with spaces in between, where lots of microbial life can live and convert organic matter and minerals into nutrients for plants.
We can plant certain plants into our fields that will improve the soil by creating spaces for water and nutrients to congregate. Each different plant will bring up different nutrients.
Planting soil health by enhancing combinations of plants is called cover cropping.
This subject matter was the focus of last weekend’s BC Forage Council’s annual Field Day, which was held near Quesnel. The Council’s website will have the keynote presentation posted soon.
It explains how in the past 40 years, we have gone from mostly considering the physical properties of soil, to considering the chemical properties, and more recently the biological life in topsoil. This aspect of soil is much more complicated and not fully understood.
We need to know more and more, for the simple reason that healthy soil can regenerate almost all of the nutrients crops need.
Take cattle or sheep, for instance, grazing on a pasture. Around 80 per cent of what goes into the stomach comes out the other end. So what about the the 20 per cent that goes to growing the animal? How is that replaced?
People who study soils will say that the replacement of the nutrients can be achieved simply by farming the microbes in the soil. They turn minerals and organic into available nutrients for growing plants.
Of course carbon and nitrogen come freely from the air if the right biology is in the soil. This is the promise of healthy soil.
At this Field Day, featuring cover cropping, we saw many of the following growing;
Legumes: Berseem clover, cowpeas, crimson clover, hairy vetch
Broadleaf: buckwheat, chicory, phacelia, plantain
Broadleaf brassicas: Bayou rape/kale, forage brassica, forage collards, forage rape, sugar beet, sunflower
Cereals/grasses: annual rye, BMR Corn, Crown Proso Millet, Festulolium, Sorghum Sudan, Teff Grass-VNS, winter Triticale
A soil quality test kit for farm use was demonstrated. It can give you basic soil properties. It was developed at UNBC. It is based on the US Department of Agriculture guide.
UNBC will conduct soils tests (e.g. water holding capacity, organic matter) at the Northern Analytic Lab service.
Other take aways from the Field Day, held at Roddie Creek Farms south of Quesnel on the West Fraser Road, were that if you are bale-grazing – that is, putting your round bales out whole for your cattle to eat and mess in, leaving behind feces, urine and organic matter – you must space them at least 40-50 feet apart centre to centre or the build up of nitrates will be too great for the grass and subsequent grazing.
A better distribution of nutrients for the soil occurs at the desired spacing. Enough research has been done to supply proof of this finding.
Personally, I am excited about concentrating on soil health as a way to keep my field management costs down all the while building the production of healthy crops from healthier soil.
David Zirnhelt is a rancher in the Cariboo and member of the Cariboo Cattlemen’s Association. He is also chair of the Advisory Committee for the Applied Sustainable Ranching Program at Thompson Rivers University Williams Lake Campus.