[johnfh]

I am hoping to clear the area where I had runner and French  beans this week.  Is it best to take out the old bean roots or is there any advantage of leaving them in for compost / nutrient value?

Any views welcome.  (Planning to put Japanese onion sets in their place - instructions from OH).

[DD.]

Leve them in. They have nitrogen bearing nodules on them.

[johnfh]

Thanks DD rather thought something like that but wasn't sure it only applied to peas.  Off to start now!

[Salmo]

The valuable parts of the roots are the root nodules that contain nitrogen fixing bacteria. The bacteria have spent all Summer using nitrogen from the air to make their protien. As they rot down the nitrogen is released slowly to be used by the following crop.

These nodules are easily seen on the finer roots. Most of them stay behind if you pull the roots quite roughly from the soil rather than digging them out with a fork. That is what I do. If the beans are just cut off they get in the way of hoeing.