Plant diversity called a must | North Dakota farmer says monoculture agriculture is a detriment to soil health
VULCAN, Alta. — While on a road trip through Alberta from Grande Prairie to Vulcan at the end of October, Gabe Brown was distressed to see nothing growing in many of the fields he passed.
Cover up that land year round, was his advice at a soils workshop held in Vulcan Oct. 30.
The North Dakota farmer firmly believes healthy soil is the key to agricultural prosperity, and the only way to reach that goal is to have a diversity of plants growing.
“If you look at true native rangeland, it is healthy,” he said.
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Healthy rangeland is covered with a diversity of plant life year round. It can hold moisture, there are no bare patches and a peek at the subsurface should reveal a thriving community of roots, microbes, earthworms and fungi.
His 5,000 acres near Bismarck were not always in good shape. When he and his wife, Shelly, took over the family farm in 1991, they were dealing with a monoculture system where half the farm was seeded to grain and the rest rested in summerfallow.
The once rich land had less than two percent organic matter after years of tillage, chemical treatments and intensive farming.
There was a lack of soil moisture, weeds, poor fertility, low yields, salinity and high input costs.
“Over time it seemed like all we were doing is we were treating more and more symptoms. As a producer, I had come to accept a degraded resource,” he said.
He learned about holistic management and started to experiment in consultation with soil scientists.
“Monocultures are a detriment to soil health. This was one of the hardest things for me to understand,” he said at the workshop, which was sponsored by the Foothills Grazing Association.
He switched over to 100 percent zero tillage in 1993 and in the mid-1990s started to plant cover crops of one to three species blends.
Since then he has expanded the variety and combinations of cool and warm season plant types. He has tried as many as 18 varieties in a home-mixed concoction, in which he uses an online recommendation for seeding rates and proper ratios.
The goal is to plant a variety of crops and then turn livestock out to graze and leave manure. His farm includes a grass finished beef program as well as grazing programs for sheep, hogs and poultry.
The farm is split into 2,000 acres of cropland, 2,000 acres of native prairie and 1,000 acres reseeded to mixed perennial forage mixes.
This is dry country that receives less than 400 millimetres of precipitation a year. About 250 mm fall as rain.
Holding moisture is critical.
The cover crops hold the soil in place, put down roots, fix nitrogen and cover the ground with dead plant material. Brown refers to that litter as armour, which protects the soil from heat, cold and evaporation.
He considers the heights as well as different leaf size and shape when planting different types of plants because each captures varying levels of sun light.
“I am maximizing solar energy by having these diverse mixes,” he said.
He might plant three types of clover for ground cover and then seed corn as a cash crop.
“You have to expand your horizons and plant some of the other plant types if you want to advance soil health,” he said.
His farm has not used synthetic fertilizer since 2008 and no pesticides since 2000.
“We are using nature to inhibit the weed growth so we no longer have to,” he said.
Brown used to consider the growing season to be from mid-May to early September but has found he can grow crops into November even after a hard frost.
“As we increased the biology in our soil, the soil temperatures are higher and we extended our growing season,” he said.
He might plant fall seeded biennials like winter triticale, sweet clover, radish, hairy vetch and radish.
“When I was just growing monocultures, the biology in the soil only had one thing to eat. When I grow these diverse mixtures, each of these species puts out different exudates for different biology,” he said.
He said mycorrhizal fungus is an underused resource. The fungal hyphae pipeline connects to transfer nutrients and water to multiple plants’ root networks. This helps satisfy the nutritional and energy needs of micro-organisms and the plants.
Mycorrhizal fungi also form a glue to develop soil particles.
“You want your soil to look like black cottage cheese because then it is stable,” he said.
Earthworms are another requirement to aerate and leave castings behind.
Livestock management above ground means making the animals do the work.
Cows calve on grass in late May and June. Fenced off paddocks are created to keep cattle moving so they do not over-graze.
The plan is to extend the grazing season as long as possible on perennial forages and cover crops. Brown said his 350 cow-calf pairs can often forage until February before he starts bale grazing.
“The beauty of the cover crops is you can really balance their nutritional needs,” he said.
Ice on snow can be a problem, but cows can dig through deep snow and adapt.
“As producers we have taken that ability from them. We provide them with a bed and breakfast instead of making cows use the four legs they have and making them harvest that forage,” he said.
“Any time I can get my cattle to go out and harvest so I don’t have to bale and start a tractor and feed, that puts money in my pocket.”
He said his system also attracts wildlife, including insects such as ladybugs and spiders, to prey on pests and dung beetles to deal with manure.
