Manure and Fertilizer Applications Affect Canola Oil Content and Fatty Acid Composition.

This two-year (2007 and 2008) study was conducted at field sites in East Lansing and Chatham, MI. Anaerobic treated swine or dairy manure and urea plus sulfur (20 lb/acre) were applied at two levels (75 lb/acre and 150 lb/acre) on spring and fall canola. Canola grain yield, total oil content and oil fatty acid composition was analyzed. The results showed nutrient applications could significantly increase canola yield. The source of nutrients, manure or synthetic fertilizer, had different effects on canola total oil content and fatty acid composition. Application of urea plus sulfur significantly decreased canola total oil content while there was no significant difference between the control treatments and manure fertilizer applications. On a land area basis, manure applications significantly increased canola oil yield. The urea plus sulfur fertilizer application decreased  canola oil oleic acid concentration relative to the nontreated control and the manure application treatment. Additionally, the urea plus sulfur fertilizer application increased  palmitic, linoleic, and arachidic acid concentration in canola oil relative to the manure application treatment. A nitrogen application level 150 lb/acre increased palmitic, and arachidic acid concentrations and decreased oleic acid concentration in canola oil relative to the lower N  application level of 75 lb/acre.