The concept of seeding legumes with HRSW is not new; our ancestors seeded sweet clover or possibly alfalfa with cereal grains prior to the widespread adoption of commercial fertilizer. Interest in reducing fertilizer inputs has increased greatly in the past few years.

What is new, however, is the myriad of legume options at our disposal. We screened literature and talked to producers to determine legume species with a potential fit in our cropping systems. We included sweet clover in this study as a legume check, based on previous research in the region.

HRSW and the companion legume were seeded in May 3, 2019 into a moist seedbed at a depth of about ¾ of an inch. The 2019 growing season had a dry spring with little significant rainfall after seeding and below normal precipitation for the entire growing season. Rain finally arrived at harvest. This preliminary data below shows the companion legume treatments with no definitive results at this time. At least four years’ data will be needed to produce reliable, repeatable results that may become recommended practices.

We will also plant a test crop without fertilizer the following year to determine if there is an impact from the residual effects of growing the legumes.

If there is enough biomass produced, the legume crop may be grazed or baled. Even if interseeding doesn’t improve yields, the practice may potentially improve soil health in the long run.

Ezra Aberle
Ezra.Aberle@ndsu.edu
Agronomy Research Specialist