Why is it not a good idea to reseed alfalfa on the same land?

Alfalfa is the third most valuable crop in the United States, with an annual value of approximately $8.7 billion. Due to its high raw protein and energy content, as well as its nitrogen-fixing ability, it is particularly important for the dairy industry. However, alfalfa has a rare and problematic property: it can inhibit the germination and development of its own seeds, a phenomenon known as autotoxicity. Autotoxicity can manifest in two forms. The first is the classic germination inhibition: if alfalfa is sown in the same area where it was previously grown, the new crop often fails to germinate. The second, less noticeable but more insidious phenomenon is self-suppression. In this case, the seeds do germinate, but the development of the main root is inhibited, and the plant performs poorly in the long term. Plants that appear healthy on the surface actually have damaged root systems, thus reducing their lifespan and yield. It has not yet been precisely identified. Phenolic ...