Can cover crop mixes of legumes & non-legume reduce nitrate leaching & protect water quality?

Cover crop mixtures of legumes and non-legumes can help farmers to add organic matter to the soil and improve nutrient management in vegetable production systems. Common legumes in these mixes are vetch, peas, fava (faba) beans that are often mixed with cereals like rye, and oats. Here, Dr. Eric Brennan (USDA-ARS) discusses the complexity of these mixtures, their advantages and disadvantages, and uses data to answer an important question: Can cover crop mixes of legumes & non-legume reduce nitrate leaching & protect water quality? The answer is YES, therefore, Eric argues that farmers should get cover crop nitrogen scavenging credits for nitrogen uptake by the non-legume component of the mixture. These credits should be incorporated into a new California regulation to protect water quality. This video is based on a presentation that Eric was asked to give to the Agricultural Expert Panel of the Irrigated Lands Regulatory Program of the California State Water Resources Control Board. This Expert Panel will give recommendations to the California State Water Resources Control Board and regional boards that are tasked to develop and implement a long-term sustainable Irrigated Lands Regulatory Program that protects California water quality while supporting the viability of agriculture. Click this link to learn more about his program https://www.waterboards.ca.gov/water_issues/programs/agriculture/2025-expert-panel.html Document with links to publications mentioned in the video. https://docs.google.com/document/d/1JTtNkkZk3aama0Aw5sBexhHtVQuNQmwQxK_BamRqkiw/edit?usp=sharing Related video: Can non-legume fall-terminated cover crop reduce nitrate leaching in vegetable systems? https://youtu.be/wERS9z_JRuA