Alfalfa

Alfalfa (Medicago sativa) grown with nitrogen during preflight testing as part of Dissecting Beneficial Plant-Microbe Interactions and their Efficacy in the ISS Spaceflight Environment, a Model Study (Veg-06). This investigation examines spaceflight’s effects on the interactions between plants and nitrogen-fixing bacteria called rhizobia. These bacteria can take up nitrogen gas from the air and convert it into ammonia, a form of nitrogen plants can use for growth. One component of the nitrogen fixation emphasis in Veg-06 will compare the growth of alfalfa with rhizobia but no nitrogen fertilizer, alfalfa with rhizobia and a source of nitrogen fertilizer, and alfalfa with neither fertilizer nor rhizobia. Results could provide a fundamental understanding of the interactions of plants and microbes for nitrogen fixation in microgravity and advance the ways to grow plants for food on future space missions. Credit: Washington State University.