Broad bean roots

If you pull up a broad bean plant carefully you will find little light coloured nodules on the roots. In these live nitrifying bacteria that take nitrogen from the air and turn it into protien in their bodies. It is these nodules that are valuable as they break down in the soil which makes nitrogen the nitrogen available to plants.

I pull up rather than dig the beans so that the majority of fine roots and nodules stay in the ground. If you cut them off the stumps get in the way when you come to hoe between the brassicas. I do not dig the ground but put brassicas in with a trowel to keep it firm. Any nodules that stay attached when you pull will break down in the compost heap.