A growth chamber study was conducted on two Saskatchewan soils to assess the effect of application of different types of animal manure with different C:N ratios on canola yield and nitrogen uptake. Treatments consisted of 13 different manure amendments with large variance of C:N ratio added at a rate of 100 mg N kg-1. Addition of the solid manure amendments in two soils generally did not result in large increases in canola yield and N uptake, except for two amendments with a C:N of about 7. Generally, cattle manures had little impact on short-term release of available N if the organic C:N ratio was in the range of 13-15 and tended to decrease N availability in the short-term if the organic C:N ratio was over 15. The N supply rate
measured by anion-exchange membrane was quite well correlated with plant N uptake differences obtained among the treatments.