It has now been shown you cannot plant alfalfa immediately on land that had grown alfalfa the same or previous year, nor even where one had been winterkilled. The current theory is that autotoxicity occurs when mature alfalfa plants excrete a chemical that inhibits the germination and growth of alfalfa seedlings
Alfalfa replant disease and related disorders
While the exact cause remains unclear, we now know it’s best to wait two or three years before trying to re-establish that alfalfa stand
