Green Manure

Whenever a visitor comes to the allotments in the summer they are usually over awed and inspired by the huge array of sights and smells befuddling their senses. During the winter season however it takes more of a connoisseur to appreciate what is going on in the ground – to the untrained eye it can just appear as a mess of brown and green. For this reason I always recommend when you try to get children interested in gardening – do it in the summer – if you try in the winter you may well lose them for life!

Today I got such a sense of satisfaction from seeing the “Field Bean Green Manure” which I planted in July is completely covering the plot I’ve earmarked for planting my maincrop potatoes next April.

I was a little worried that I had planted the field bean green manure too late and the bacteria (which forms the symbiotic relationship whilst living in the plants root system and drawing nitrogen from the atmosphere to be converted into ammonia which can be absorbed by the plant as explained below) would be dormant as it is most active in the summer – but it seems I got them planted in time – phew!

Potatoes are a big consumer of Nitrogen – and to get a good crop you should use a good nitrogenous fertiliser – the green manure crop which I’m using was specifically chosen for the legume families well known attribute of “Nitrogen Fixing”.

What is Biological Nitrogen Fixing?

Discovered in the late 1880’s by the German agronomist Hermann Hellriegel and Dutch microbiologist Martinus Beijerinck biological nitrogen fixing uses bacteria naturally present in the soil to take nitrogen gas from the atmosphere and convert it into ammonia which is readily absorbed by the legume plant, resulting in a healthy nitrogen rich dark green leafy specimen (as you can see in my picture!)

So now each time I walk into my allotment in the dreary winter months ahead I’ll get a little feeling of satisfaction seeing my green manure success! I will soon be cutting them down before they flower and then I’ll dig them into the soil as the perfect bedding preparation for my nitrogen loving maincrop potatoes!

One thing to keep in mind when using green manure is to watch out for slugs and snails – they thrive in the shady damp atmosphere underneath the legume plants leaves – use plenty of slug pellets and you should be ok!


Leave a Reply

Your email address will not be published. Required fields are marked *