Tuesday, 10 October 2017

Allotment: to dig or not to dig?

On our allotment the remaining few beetroot and leeks will be lifted shortly, leaving only the raspberries, gooseberries and rhubarb. Other than these permanent plantings we are now 'putting the plot to bed'. Having said that we are looking to next spring with broad beans sown and red onion sets already planted.
Our last few leeks are about to be lifted. Drayton Allotments, Daventry.
10 October, 2017

Onions and broad beans share an interesting history - or perhaps I should say lack of history - for neither is known as a wild plant. The broad bean, Vicia faba, seems not to have been in existence as a crop prior to the Neolithic period although it may have been in cultivation in the Middle East as long ago as 6000 BC.  It apparently arrived in Britain during the Iron Age, i.e. a few centuries B.C. but we cannot be more precise. The seeds would not have been contained in today's non-shattering pods so harvesting would have required careful timing [Ref 1]. As for onions, Allium cepa, we have several wild onions native to north west Europe, notably Ramsons, Allium ursinum, but modern onions - together with leeks and garlic - seem have no definite or obvious wild relatives. Obviously onions and leeks did have wild progenitors but, like tea, Camellia sinesis, they appear to be extinct. Incidentally our leeks look quite emaciated but the variety was developed to be gathered when the stems are no more than  a couple of centimetres wide.
Traditionally autumn on an allotment involves extensive digging and limited areas of our plot will be dug over but I am increasingly doubtful about the value of all this hard labour [Ed: That's because you're getting old!]. So why are so many of us out there, collectively turning over I guess several million tons of earth?
A no-dig policy involves simply spreading a layer of manure on the soil.
10 October, 2017

When, some months back, Chris announced that she would like an allotment I was uneasy but I went along with the idea as I felt that the activity would be therapeutic in her recovery from cancer. In fact I have enjoyed it far more than anticipated. As Jeremy Corbyn said when questioned about his personal commitments should he become prime minister, 'Why would I give up my allotment? I think there's a need for everyone in life to balance what they do...[and] you do your job better if you give yourself time to collect your thoughts and do something else.'  Not everyone fancies an allotment so for others it will be a round of golf or blasting a few brace of birds out of the sky on a grouse moor, the latter heavily subsidised by the taxpayer, the ultimate 'magic money tree' [Ref 2]. But these leisure times are important and I admit that I find digging valuable as a way of unwinding; when I turn over the soil I also turn over my thoughts. But let us return to the question: why - other than for therapeutic reasons - do we do it?
Well, it buries the weeds. That is clear and, once they are buried, they will decompose and release their nutrients, returning them to the soil as humus. What else? I have scratched my head and can come up with nothing. It is argued that it breaks up heavy soil and lets in the air but this is a very moot point. Most plants root better in firm soil. At times the soil may feel compacted and dense but is in fact full of air channels - tiny but adequate for the growth of crop plants. Breaking up the soil seriously damages its structure and causes extra loss of moisture via evaporation. We also seriously damage the invisible but immense network of saprophytic fungi that exists beneath virgin soils and which provides vital help (there can be five metres of their mycelial threads in a gram of soil) in breaking down organic matter. As for weeds, other than the most stubborn of perennials such as brambles and bindweed, they should be hoed off and composted. Rather than dig in the compost -  or manure if I can get it - I intend to simply spread it on the surface and allow worms to drag it down. 
The best plot holder on our site does just that and her results are impressive. The concept of a no-dig plot is not new but it seems to be gaining in popularity. Its advantages are staring us in the face.
I hope I am not too old to learn.


1.  Stace, Clive A. and Michael J. Crawley (2015)  Alien Plants. William Collins
2.  Monbiot, George  Black Hole. Guardian Newspaper, 18 August, 2016

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