Five Years of Continuous Organic No-Till Grain Production: Lessons Learned.

Both no-till and organic farmers often pose the question “Can we develop an organic no-till system?”  Such an experiment was started in Carman, Manitoba in 2008.  The rotation was a barley/hairy vetch green manure (2008); flax (2009); oats (2010); barley/hairy vetch green manure (2011); wheat (2012); fall rye (2013).  The experimental design was a randomized complete block in a factorial arrangement with 4 replicates.  The rotation was managed with no-till and tillage under both conventional and organic management.  Total biomass production in the barley/hairy vetch green manure was approximately 7000 kg/ha in both 2008 and 2011.  The barley/hairy vetch was blade rolled in mid-July.  Rolling kills the barley but the hairy vetch continues to grow until freeze-up; allowing more biomass accumulation. No difference was observed in till vs no-till organic crops in 2009 and 2010.  By 2011, wheat in the organic no-till treatment produced only 1000 kg/ha of grain yield (1/3 of the tilled organic treatment) owing to competition from perennial weeds, mostly dandelion and some Canada thistle.  This observation suggests that long-term organic no-till may have limits.  Fall rye was seeded into the wheat stubble in September, 2012 and then sheep were used for pre-emergence weed control.  It is hoped that the competitive nature of fall rye will allow for a successful 6^th organic no-till crop.