Yield and quality of oat in response to varying rates of swine slurry

An experiment was conducted at two locations in southern Manitoba in 2001 and 2002 to assess the effect of multiple rates of spring-applied swine slurry on seed yield, kernel quality, dry matter accumulation, protein concentration and lodging response of three adapted oat (Avena sativa L.) cultivars: AC Medallion, AC Ronald and AC Assiniboia. Treatments included three rates of swine slurry, an unfertilized check and an inorganic fertilizer treatment at the recommended N rate. In spite of the nutrient variability in swine slurry, oat grain and dry matter yield remained largely unresponsive to increases in slurry rate except when residual soil nutrients were very low. Thousand kernel weight and percentage of plump kernels appeared to be affected more by environment and cultivar than by slurry rate. High rates of swine slurry did not result in high crude protein concentrations in grain or dry matter and may, under some environmental conditions, decrease protein concentrations. The data suggest that few differences exist between oat cultivars in response to the use of swine slurry as a fertilizer. The inconsistent response to slurry application indicates that oat may not be the ideal crop to use in the year of slurry application but may respond well to residual nutrients from nutrients applied in the prior year.Key words: Oat, swine slurry, grain yield, biomass yield, crop quality