The market for organic vegetables is increasing. As conventional farmers transition fields to organics to meet this demand, there is a need for better organic nutrient management guidance, especially for nitrogen (N). Organic N management is more challenging than conventional N management due to a higher level of uncertainty surrounding the N supplying capacity of an organically managed soil as well as the constraints of organic fertilizers (supply, application timing and placement, and uncertainty of release rate and amount). As a result, conventional nutrient management strategies may not be appropriate for organically managed systems. With organic N management there is often a higher risk of excessive nitrate-N loss and higher risk of not achieving economic yield targets.