Strategies to Improve Canola Establishment and Winter Survival in Conservation Systems.

Conservation wheat systems in the southern Great Plains include canola in rotation to assist with disease and weed control. This study evaluated effects of no-till, vertical tillage (VT) [Great Plains unit with a gang angle of 0°, 3°, and 6° and a Landoll unit], burn, harrow, and a cover crop on establishment and winter survival of canola (Brassica napus L.).  Canola was sown in September at Fairview, OK and October at Chickasha, OK.  Plant stand was evaluated on 3 October 2014, 19 November 2014 and 13 February 2015 at Fairview and 19 November 2014 and 18 February 2015 at Chickasha. At Fairview, all degrees of the Great Plains VT resulted in a mean increase of 2.3 plants m^-1 over the no-till, burn, and harrow treatments across sampling dates. In Chickasha, the burn, Great Plains 0°, Landoll, and harrow resulted in a mean increase of 2.8 plants m^-1 over the no-till and cover crop treatments. Yield collected from Fairview indicated no difference between treatments with a mean yield of 1681.1 kg ha^-1. Chickasha yield resulted in no-till having the highest yield of 2146.4 kg ha^-1 while harrow had the least at 1188.1 kg ha^-1. Composite soil samples were collected to a depth of 10 cm to measure the effects of shallow tillage on active carbon and glomalin content. This data will deliver insight into the potential need of a light tillage pass in canola and wheat rotations to increase the productivity of winter canola while maintaining high productivity of the soil.