By Martin Entz
Professor of Cropping Systems and Natural Systems Agriculture, University of Manitoba
I remember visiting with pioneering no-till farmer Bob McNabb, of Minnedosa, Man. I learned a great deal from Bob and his fellow no-till farmers.
On one field tour, Bob asked me about the possibility of a no-till system under organic management.
It really did seem like a pipe dream back in the mid-1990’s, but I have never forgotten that conversation, and that challenging question.
What really impressed me was Bob McNabb’s willingness and interest in “pushing the envelope” on no-till farming.
Note: Bob’s four-wheel drive pickup pulled my two-wheel drive university pick up out of a mud hole that day. Thanks for that too Bob!
Fast forward 20 years…. The picture at top shows the University of Manitoba’s organic no-till pioneer, Keith Bamford, standing in an emerging flax crop. The flax was no-tilled into the mulch on land that had its last fertilizer and herbicide application in 2003. In other words, this is on long-term organically-managed land. The picture was taken on May 27, 2016 at Carman, Manitoba.
Mulch was produced by growing a barley/hairy vetch cover crop the previous year and managing that cover crop with a blade roller. The blade roller helps control annual weeds that grow in the barley/vetch intercrop and the roller also kills the barley at heading.
The hairy vetch is not affected by blade rolling and will continue growing until late fall. It will then winterkill (except in Southern Alberta – see recommendations further down). Keith blade rolls from one to four times per season.
The flax crop in the image is just emerging. 2016 was a very dry spring — it was not until well after seeding that significant rainfall was received in the Carman area. So these flax seedlings got started with the soil moisture conserved under the mulch, enjoying the benefit of no-till farming.
One observation is that having barley in the mixture helps to “pin” the mulch down in springtime, which helps it from blowing after seeding. Keith feels that wider row spacing is a good idea since this leaves a wider strip of mulch between the sliced rows, reducing the risk of mulch blowing. It goes without saying that only disc no-till drills are suited to this system.
Keith started working on no-till organic flax production about 10 years ago. His average flax yield in this system is 24 bushels per acre.
At the typical organic price of $30 to $40 per bushel, this is a very profitable organic crop. Our cost of production at Carman is about $170/acre for the barley/hairy vetch mulch and about $200/acre for the flax.
This system also works well for wheat, oats, other cereals as well as sunflower, and other oilseeds. One caution for farmers in Southern Alberta; the hairy vetch tends to overwinter in your part of the world (that is what happened at our sites at Lethbridge for two years in a row).
- This system is best suited to the Black soil zone where at least 8000 kg/ha of mulch dry mass can be produced in Year 1. Any less biomass will lead to poor weed control.
- Do not skimp on seeding rates. Keith uses 25 lb/acre hairy vetch and 50 lb/acre of barley (could also be oats).
- Roll the field as often as required for barley control and control of weeds such as wild oat, foxtail, mustard and other annual broadleaves.
- Do not use this system if you have REALLY bad wild oats. One of our PhD students, Caroline Halde, tried this system when wild oats were really bad (about 500 plants m2) and the mulch was not able to suppress them.
- Not well-suited for Southern Alberta due to mild winters that allow hairy vetch to overwinter.