Using leguminous cover crops provides multiple below ground ecosystem services that support crop production, restore/maintain soil health and reduce undesirable environmental consequences. The first part of the presentation will focus on understanding soil ecological processes that enable leguminous cover crops to serve as a nitrogen source for subsequent cash crops. Followed by discussing how leguminous green manures alter nitrogen cycling compared to additions of mineral fertilizers. Then, digging deeper into the underlying soil ecology and look at how leguminous cover crops affect soil organic matter formation and improve soil health. Lastly, we will consider how plants acquire nitrogen from organic sources in soils. In the second half I will concentrate on management practices. To optimize legume-derived nitrogen supply, there are two main aspects of management to consider: 1) How can leguminous cover crops be managed to optimize symbiotic nitrogen fixation rates? and 2) Which management strategies are most effective for transitioning from mineral fertilizers to legume-derived nitrogen? I hope we can have some discussion about management challenges that farmers face when transitioning to legumes as nitrogen sources as well as practices that are working.