Two trials were conducted to evaluate the contribution of nitrogen (N) from a mixed legume/cereal cover crop to the successive organic broccoli crop. Trial No. 1 was conducted at the Center for Agroecology and Sustainable Food System organic farm at the University of California Santa Cruz and Trial No. 2 at the Hartnell East Campus Research Facility in Salinas. Cover crops were grown over the winter and incorporated into the soil in the spring of 2006. A randomized block design or a split plot design was utilized with cover crop and no cover crop as the main plots and 0, 84, 168 and 252 kg-N/ha of commercial organic fertilizer(s) as the other main plots (Trial No. 1) or the split plot treatment (Trial No. 2). Broccoli was grown to maturity.  Mineral N in the top 30cm of soil was measured over the season, N in above-ground biomass (broccoli-N) was measured at midgrowth and at harvest, and harvest evaluations were conducted. Broccoli yield was significantly increased by both cover crop and organic N fertilizer applications. The cover crop in Trial No. 1 contained 179 kg-N/ha. N-uptake by broccoli indicated 42 kg more broccoli-N in the cover crop treatments at harvest. The cover crop in Trial No. 2 contained 218 kg-N/ha. 300 mm of rain fell between incorporation of the cover crop and planting of the broccoli.  A sizeable portion of mineralized N from the cover crop was assumed to be lost to nitrate leaching. Evaluations of N uptake indicated 30 kg more broccoli-N in the cover crop treatments at harvest. These results showed that 14 to 23% of cover crop N was utilized by the successive broccoli crop. Further, incorporated cover crops increased broccoli-N in a manner similar to 67 to 90 kg-N/ha of applied organic fertilizer.