Abstract
For many Idaho growers, annual manure applications are a necessary part of their farming system. This often results in high soil available nitrogen, frequently greater than 400 lb/A (3ft soil test). High nitrogen tends to lower sugarbeet sugar % and reduce sugar juice quality. These high nitrogen soils are problematic, and there are no established agronomic guidelines for how to optimize sugarbeet productivity on these soils. Anecdotally, growers report that some sugarbeet varieties perform better than others at high nitrogen levels. Perhaps variety selection provides the key to maximizing returns on these high nitrogen soils. Over two years we established field trials in Liberty, Idaho to evaluate the performance of commercial sugarbeet varieties under high nitrogen conditions (500 lb. N/A). Our results show that varieties performed differently relative to one another, and that some varieties could return high yields and good sugar % when grown under high nitrogen conditions. The interaction effect between sugarbeet variety and nitrogen level has broader implications for our industry and suggests that there is an optimal nitrogen level for each variety and that we may need to reconsider our one-rate-fits all approach to nitrogen recommendations.