Alfalfa was underseeded to Smart canola in the spring of 1999. All the alfalfa was seeded at 8 lbs/ac while the seeding rate of the canola was 3 lbs, 5 lbs and 7 lbs. Three alfalfa treatments were seeded without any canola. Roundup was applied to all treatments pre-seeding at a rate of 1.0 l/ac and Pursuit was applied in-crop at a rate of 0.085 l/ac. The first pure alfalfa treatment was allowed to grow the entire season. The second treatment had one cut taken in the summer of 1999 and the third treatment was left to grow and then a dormant cut was taken. The canola yield averaged 50 bu/ac regardless of canola seeding rate.
The alfalfa in all the treatments survived the winter well. Growth began early and the alfalfa in the treatments that had been cut either through mowing or the harvesting of the canola, soon caught up to the treatment that had been allowed to grow without any cutting or mowing in 1999. The first cutting of alfalfa occurred July 31 and the second cut was taken August 22. The average of the 2 cuttings from each treatment appears in the graph below. The difference in yield is not significant.
Yield of alfalfa in 2000 cut in year of establishment vs. that not cut
In this test, the alfalfa proved not to inhibit the yield of the canola. Cutting in the year of establishment did not appear to affect alfalfa yields the following year. It should be noted, however, that the moisture levels in both years were adequate for crop and hay production. It is unclear if, in years of insufficient moisture, the establishment of the alfalfa would be adversely affected by the canola or if the mowing and cutting in the year of establishment would affect alfalfa production in the second year.
This project was made possible by funding from BASF and the assistance of staff from the ECRF, SA&F and SSCA.