The legume is commonly recommended as a companion plant. It is believed that the excess nitrogen produced by the legume will help feed the companion growing next to it. In the Three Sisters agriculture system the bean provides nitrogen for the corn to grow and since corn needs a lot of nitrogen, it grows better.
Legumes are also an important ingredient in crop rotation. Grow corn one year and follow that up with beans or peas the following year to restore the level of nitrogen in the soil.
There is no doubt that legumes are able to capture atmospheric nitrogen (using bacteria) and convert it to plant usable nitrogen, but how much of this actually benefits other plants? Are legumes a good source of nitrogen for the garden?
