I don't think we have any particular research on that very specifically. In general, organic production may or may not be more conserving of nutrients, if I can put it that way. It depends an awful lot on soils, on tillage practices. Just because it's organic doesn't mean you're using one particular tillage practice over another tillage practice. It will depend a lot on what practices you're using in your organic practices. There's no specific set of practices that qualify as organic, and quite a range of potential outcomes.
On February 13th, 2014. See this statement in context.