New sugarbeet fertilizer guidelines for Minnesota: What to know about nitrogen and micronutrient management

By: Dan Kaiser, Extension nutrient management specialist

The sugarbeet fertilizer guidelines for Minnesota were recently updated for the first time since 2015. Here are a few things to know about the new guidelines.

Nitrogen

Nitrogen guidelines are the same as those promoted by Minnesota’s sugarbeet cooperatives. There currently is a project underway that is funded by the Sugar Beet Research and Education Board of Minnesota and North Dakota looking at rate and sources of urea applied in fall and spring, which was discussed in a blog post last year. At this time, we do not have any overwhelming evidence that any changes need to be made to the N guidelines for sugarbeet, but we are in the process of compiling recent and historical N rate research so I can evaluate the response to N in the various growing regions as more data is collected.

Secondary and Micronutrients

The only changes that were made to the sugarbeet fertilizer guidelines are the inclusion of information on sulfur, boron, and manganese application. The majority of our recent research has not shown the need for sulfur and boron in the bulk of regions where sugarbeet is grown. This does not mean that deficiencies may not be present in some fields. Sulfur and boron are more likely to be deficient in sandy soils lower in organic matter. In the case of boron, dry soil will typically result in a greater chance for boron supply from the soil to be low. It is not uncommon to encounter low boron in plant tissue when plants are moisture-stressed, which can make it difficult to determine whether the problem can be corrected with a fertilizer application or if the deficiency will persist as long as the soil remains dry. Over-application of boron can be detrimental to crops, so avoiding application of boron is best to reduce the potential risk of a reduction in root yield.

The other micronutrient that is thought to be of concern for sugarbeet production is manganese. Soils in Minnesota have not been shown to respond to manganese for most crops. Also, some treatments for Cercospora leaf spot contain micronutrients like copper and manganese, so the actual need to do a separate application of manganese is very low. There are guidelines for manganese application to sugarbeet in Michigan but some Michigan soils have been documented to be deficient in manganese, whereas deficiencies are not common in Minnesota. This illustrates the point that fertilizer guidelines have regionality to them and soils do vary across the country in how they supply and hold nutrients.

View the full sugarbeet fertilizer guidelines for Minnesota

If you prefer a printable PDF version of the full publication, you can email us at nutmgmt@umn.edu.

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Support for Minnesota Crop News nutrient management blog posts is provided in part by Minnesota's fertilizer tonnage fee through the Agricultural Fertilizer Research & Education Council (AFREC). Learn more at MNsoilfertility.com