Building Carbon in Soil

Studies on grassland grazing soils confirm healthy soil is a valuable buffer for drought or flood

Two recent soil-focused studies done in part on the benefits of grazing systems in Manitoba are showcasing the connection between grazing and improved water infiltration into the soil, a positive impact in production which may bode well for some of the forecasted dry times ahead on Canada’s Prairies.

Dr. Terence McGonigle of Brandon University recently finished two years of a three-year project funded by Manitoba Agriculture and Resource Development on six Manitoba fields that was developed to complement a Canadian Forage and Grassland Association Agricultural Greenhouse Gas Project on same fields that wrap-up this year. During similar time periods, University of Alberta researchers, Dr. Mark Boyce and Dr. Edward Bork, recently presented results of their Adaptive Multi-Paddock (AMP) Grazing Study in Workshops held on Wednesday, March 3rd and Thursday, March 4th hosted by ALUS Canada.

article continues below

“With more grass and more days of grazing needed for livestock production, improved water infiltration, improved plant communities and enhanced vegetation biomass and litter are all signals of healthy soil and productive lands,” said Larry Wegner, MFGA chair. “Both projects have shown this to be true on the grazing lands that can provide production benefits while having a greater ability to buffer the impacts of climatic events such as droughts and floods via the water infiltration abilities of the soil.”

McGonigle’s GHG study measured shallow cores to 15 cm depth taken in all years. However, additional deep cores to 100 cm depth were taken where possible across field sites in 2020, dividing those deep cores into depth intervals. This study has one year remaining under Manitoba Agriculture Resource and Development and pinpointed the range of values for carbon stock in Southern Manitoba. McGonigle’s study also found bale grazing provides a pronounced stimulation of grass cover in the location of the former bale, and that water infiltration rate was faster under planned grazing.

· The AMP grazing study detailed improved water infiltration, enhanced vegetation biomass and litter as buffers against drought, as well as increased absorption of methane into the soil and more soil organic carbon.

Wegner touts MFGA’s belief that any farmer operating their farm in ways that put more carbon into the ground is doing good service to the greater community. He says that beneficial management practices and the focus on water and soil bode well for health of the soil as well as the greater ability of the soil’s water infiltration abilities to get through potentially challenging times. Wegner says the soil health aspects of on-farm water management will be a key component of MFGA’s participation in the Federal Government’s carbon consultation opportunity currently under way.

Wegner has been using soil-boosting, planned grazing practices on his Virden, Manitoba-area farm for the last 15 years. He says that he recently heard a presentation that stated farmers need to be prepping for drought three years out. He figures some Manitoba producers might be right on that exact path should dry times prevail in coming months. Still, a drought is a beast no one ever hopes to see. 

“It’s important to start prepping for a drought in the wet years,” says Wegner. “Remember a properly managed pasture can respond quickly after a rain but an over-grazed pasture can take years to recover…. if ever. You can NOT feed yourself out of a drought so it’s critical to have a plan.

Here are some of Larry Wegner’s drought preparations

· Amalgamate your herds

· Do a forage inventory and match the livestock to the forage inventory

· Prioritize your herd into sustainable carrying categories

  A - keeper herd

  B - can be sold but would prefer keep

  C - will be sold if it gets dryer

  D - can be sold anytime 

· Talk to Manitoba Agriculture Resource Development staff to help make a plan

· Connect with producers that have grass when the others do not. What are they doing different?

© Virden Empire-Advance