Grow Box Windows Show Cover Crop Roots

“Visitors to our field day were really impressed with two 4-ft. by 6-ft. by 3-ft. deep growing chambers that showed the rooting value of cover crops,” says Reid Allaway of Tourne-Sol Cooperative Farm in Quebec. One side of the rectangular chambers had a slanted heavy-duty acrylic window that showed exactly how roots penetrate deep into the soil during the growing season.


     Allaway says in the past, they’ve used field root pits to show how deep roots penetrate, but they’re a mess to dig, roots are difficult to wash, and if the weather doesn’t cooperate, the pits aren’t very effective. “The above-ground growing chambers let people get a very close look at the impressive root array of various species growing against the clear plexiglass,” Allaway says.


     Tourne-Sol acquired the chambers from the Agricultural College and National Organic Agricultural Institute in Victoriaville, Quebec. Students and professors built them to research root development in any crop. The clear plexi was covered with fiberglass insulation and plywood so roots could grow without direct sunlight during the growing season.


     Allaway says they filled both chambers with soil, creating A and B horizons like their fields. They compacted one of the chambers when the soil was wet and watered both chambers differently. A range of legumes were grown without fertility amendments.


     “The big surprise for me,” Allaway says, “was the impressive roots on red clover, hairy vetch, and fava beans, even when foliar growth was modest. Visitors were impressed with the visualization and could more easily understand how cover crops develop root biomass that can penetrate even compacted soil. Roots from legume and cereal cover crops stay in the soil and become organic matter that benefits productive crops.”


     Contact: FARM SHOW Followup, Reid Allaway, Tourne-Sol Cooperative Farm, 1025 Chemin St-Dominique, les Cedres, Quebec, Canada J7T 1P5 (ph 450-452-4271;;