March 21, 2024
Cover crops have traditionally been utilized to help hold soil when transitioning between different types of cash crops—to prevent erosion--and were plowed under before planting the next crop, to add organic material and fertility to the soil.
Today, farmers with livestock often select cover crops that can be grazed, adding an additional benefit (feed for livestock) and the added advantage of animal manure.
Grant Lastiska, originally a Livestock and Forage Business Specialist with Alberta Agriculture and now with Union Forage, says some of the new cover crops mixes can be very beneficial for cattle.
“In conventional grazing systems we either have an annual that starts growing later in the spring and finishes growing sooner than the perennial forages, or a perennial pasture that lacks productivity,” he says.
“The ability for these stands to take in water and hold it has decreased. Using cover crops can help remedy this. Years ago I worked with fall rye, and looking back at some of the work in Alberta and the U.S. that was done in the 1960’s showed that if you add nitrogen to a system it improves water use efficiency. Cover crops mixes that some people are using include a legume. This contributes nitrogen to the system, ” he says.
“Adding root crops also gives ability to get down through the hardpan with root channels. Research with alfalfa shows positive results after an alfalfa crop. There is science to support the use of cover crops to help soils—adding nitrogen (to improve water use efficiency), root channels (to aid water infiltration) and ability for plants to follow those channels thereafter. With the mosaic of species in a mix of plants, grasses can derive nitrogen,” he says.
Grazing part of ecology
Now some people are putting systems together with this in mind, looking at ecology of systems. Grazing is part of that ecology.
Studies in the late 1800’s and early 1900’s showed the amount of erosion under different systems. “If we cover the landscape to prevent erosion and have more water infiltration from mass on the surface, it translates into better water capture. Any good grazing system or pasture must have litter; otherwise moisture runs off and you don’t have a functioning ecosystem. We need the sponge effect, along with cool soil (shaded by plants, rather than bare and baking in the sun), good infiltration (to keep raindrops from hitting the soil surface so hard), etc.” says Lastiwka.
“Using a legume, a root crop and a cool season grass with user-friendly arbuscular mycorrhizal fungi (with the fungus penetrating the root cells in a symbiotic relationship) makes a beneficial mix. Warm season broadleaf plants may also be beneficial. With grazing animals this can create a healthier land and more productive soil,” he says.
Kevin Elmy (Friendly Acres Farm in Saskatchewan) often consults with cattle producers regarding ways to improve pasture production and regenerative agricultural management systems, and recommends using cover crops. “David Montgomery, a geologist from the University of Washington, wrote a book called Dirt: The Erosion of Civilizations. He said that basically every civilization has collapsed and failed because the soils fell apart, from overuse, and were no longer fertile,” says Elmy.
The Fertile Crescent
The Persian Empire was an early civilization in an area called the Fertile Crescent in the Middle East. Mesopotamia, the part of the Fertile Crescent between the Tigris and Euphrates Rivers, was where several early fertilizations flourished, thanks to fertile soil and irrigation from the two rivers. Early farming efforts and advances in agriculture blossomed, enabling civilizations to grow in size and complexity. This area is now Iraq and Iran, and mainly desert, due to the way those early farmers mismanaged that soil.
“The Aztec civilization in Central America did the same thing. Soil deterioration also occurred in Greece and Rome. In North America we are now in the same process. I was recently talking to ranchers about rejuvenating tired pastures and told them we need to change our perspective. We are actually not cattle producers; we are grass managers. We grow grass to feed our cattle, and cattle are our best tools for managing the grass, and also for solving the problems of over-cropping on a farm,” says Elmy.