Sunday, 28 June 2015

Crop Production History - Market Gardens

Crop Production History - Market Gardens

... and can growing food in an environmentally way be achievable?

I am trying to work out how much food we need to grow to provide us with enough calories / nutrition for 3 main meals per week, for the whole family, and to see if this is even remotely feasible. Can you live an environmentally friendly lifestyle without harming the environment?

A quick ball park calculation was done with Potatoes. 

If we say that potatoes should form a 3rd of a meal and that your main meal should provide 50% of your calories per day and that potatoes contain 800 calories per kg and that adults require 2,000 calories per day and children require 1,500 calories per day we arrive at:

Adults require 2,000+ calories per day (400 breakfast, 600 for lunch, 600 for main - rest are snacks and junk)

Children require 1,500 calories per day

Adult main meal = 600 calories and children's main = 500 calories we get (2 adults and 3 children):

2 x 600 + 3 x 500 =  2,700 Calories per main meal

Potatoes need to provide a 3rd of these = 900 calories per day x 3 days = 2,700 calories per week

2,700 calories per week for a year = 140,400 calories per year.

140,000 divided by 800 calories per kg gives us 175 kg of potatoes per year need to be grown.

Our 1st early potatoes seem to be producing 0.5 kg each plant and I presume that the main crop will produce 1.5 kg per plant so I'll presume an average of 1 kg of potatoes per plant.

That would require growing 175 potato plants. If each plant takes up (including spacing) 0.75 sq metres we need 131 sq metres of potato bed (11.5m by 11.5m bed). That sounds like a huge area, bigger than many peoples garden just for potatoes and that is just for under 50% of a families main meals for the year.

These simple calculations only account for a 3rd of our calories for under half of our main meals and doesn't include breakfast or lunch. The rest of the calories have to come from elsewhere and be spread over as many different vegetables as possible. We could plan our yearly food, or as much as we want like this and find out how much space we need to provide for veg and fruit.

That got me thinking about productivity and comparing it to farmers or more specifically Market Gardeners of the past. 

We seem capable of producing 1.33 kg per sq metre which becomes  5.4 tonnes of potatoes per acre. How does this compare to past commercial production before the real intensive farming started?

The Development of Market Gardening in Bedfordshire 1799 to 1939
Luckily I found a report / document entitled with the above at which is a very interesting read.

Within the first few pages we find that Carrots and Onions (which I think are similar in weight to potatoes) were averaging 200 Bushels per acre around 1810. 

Using a document from we find that a Bushel is about 57 lbs for Onions and about 50 lb for Carrots. Taking 57 lb per Bushel we get 11,400 lbs per acre and converting into kg we get 5,175 kg (5.2 tonnes) per acre. That matches almost precisely what I think we can produce.

Reading a little more, land rent was around £2 to £3 per acre then, rising to £5 to £6 per acre for a cleaned and manured acre for potatoes.

Throwing these figures into an inflation calculator from the Bank of England we see that land was being rented in 1810 (at 2014 prices) at £140 to £210 per acre and £385 per acre for prepared land. According to DEFR a comparable price for land now is about £66.50 per acre (2013 prices) which is at least half the price compared to the 1800's.

It appears that our garden production is on a par with growers back in the early 1800's and compare that to today's commercial yields of approximately 18 tonnes per acre. Commercial intensive farming for potatoes is over 3.3 times what it was, or what it is compared to an ordinary gardener.

Finding a document suggested that in 1810 potatoes were selling for 3.15 shillings per hundred weight. Rough calculations suggest this is about £0.22 per kg in today's money. On the local market potatoes (different types) sell for between £0.75 and £2.00 per kg. Taking an average, £1.35 per kg now compared to £0.22 we see that potatoes are around 6 times more expensive to buy now compared to prices in 1810.

My calculations may be a bit off, and depending where you find documents the yields that get reported back in time vary massively and I may not be comparing like with like in reality but a couple of hours reading and converting has certainly been very interesting.

Permaculture people often say that their way of growing can compete with, and is better for the environment compared to modern intensive farming, for all sorts of reasons, but taking productivity into account I can't see it myself. Considering how much food needs to be produced now, compared to when so many more people used to grow their own, and efficiency gains that have been made, it would appear to me that permaculture, and home / small scale growers are only ever going to be niche market and something that can only be practised by the few for their own peace of mind.

By working out how much food I can produce, and the space taken up when you include lots of different vegetables I can't see how being self sufficient can work for many people, if any. The work involved and space required would limit our own growing to be little more than a token, supplementing our main food shopping.

We will still aim to grow as much as we can but when you scale up the needs of 5 people in a family, requiring food 7 days a week, 52 weeks a year, it looks impossible to sustain a family on home grown food whilst at the same time earning enough to pay for cars, school, home furnishings and the comforts of life, there simply isn't enough time, space, energy or earning potential from surplus food produced from a large garden.

I can see that it could potentially be possible to be self sufficient and grow organically, and can see that it may have been in the distant past, but in modern times it would require a large pot of cash to start with, enough to buy a house with land, enough left over to pay for your bills (electricity, council tax, clothes and home furnishings and tools etc) and enough money to support yourself in old age. But, that requires someone giving you that money or you being lucky enough to earn enough, quick enough to be able to give up work when young in order to have enough time and money to produce your own self sufficiency. Earning money or being given the money, land and a home must have included or relied upon someone damaging the environment to get to that position.

In the past, without intensive farming practises and chemicals for pests etc, growing your own food and being self sufficient may have been possible but only if you were able to tolerate no electricity, no running water, no carpets to replace, no home decorations, no new shoes and no creature comforts at all and then just exist. In modern times we are not prepared to accept those conditions and so must work to pay for those. This is why nasty chemicals, very intensive farming practises were developed so as to give enough space and time in your life to be able to climb out of the gutter and to have a life rather than just exist in shabby conditions.

Living in an environmentally friendly way, growing your own food to avoid chemicals and to have better quality food is a nice dream, a very worthy goal to achieve, but seems totally implausible when taken to it's logical conclusion of a total life lived that way. I see permaculture, or an environmentally friendly lifestyle, as being a token, a way to reduce our impact on the environment and not a replacement.

I think I understand why old style subsistence living was replaced by modern practices and damage to the environment and I am now on a quest to find people blogging about permaculture, or low environmental impact living, who publish their own food produced by weight, to show that they can grow enough for a family year on year in a sustainable way. I'd like to see if they manage this and have time to earn enough money from an environmentally sustainable job to run their family or life using the permaculture principles, and preferably within the UK. It'd be nice to see just how far people can, and have, taken this. I'm not sure that I would be capable of producing 30 or 40% of our total food for the family on half an acre year after year.

So far I have found a few people who publish their food growing harvest, who claim to be living in an environmentally friendly way, but none of these come even close to producing 10% of one persons calories for a year. I think that by the very nature of wanting to see a blog of their efforts, I am ruling out the type of people I want to read about, simply because in order to have the internet and blog they must be spending most of their time working, probably damaging the environment greatly, in order to be able to afford the luxury of the Internet, which will be only one luxury among many. Let's be more realistic, can I find a blog to see just how far a family can go toward being environmentally friendly in the modern world, whilst still having a few luxuries that damage the environment needlessly?


1 comment:

  1. HI Andy,

    really interesting post. I agree with your conclusions about self-sufficiency. Have you seen this document: ?

    It estimates about twice the yield for potatoes without chemicals, but I don't know that that changes your conclusions much.

    My motivation has been to see what I can grow on a backgarden scale with a minimum of time and other inputs alongside working full-time. I don't kid myself that I could feed my family with the output on its own, but I think it could make a real contribution. In a world of raised energy prices and raised food prices as a result, the ability to grow a fraction of food requirements without the need for transport would be a real benefit. I've been getting back into the idea of Transition Towns again recently (Salisbury Transition City has just launched). I can envisage a future where we need a combination of part-time very local food production (gardens, allotments, community orchards and productive tree crops), alongside local farming serving local markets. Trade would still play an important role but we wouldn't waste fuel transporting things that could be grown locally. I can see forest gardens having a part to play in that. I daydream of a city-wide productive patchwork of individual forest gardens. A little bit like the way the Amazon was farmed in the dim and distant past.

    In practical terms, the output from my immature forest garden has been similar to your estimates for potatoes at about 2 ton per hectare. One year it was nearly double that, but only because I turned the front garden over to potatoes! I estimate that when the canopy trees are more developed that will increase by a factor of 2-4x, perhaps to a maximum of 8 tons per hectare. That seems pretty good compared to the numbers for arable production in the document above (4.3 ton/ha), certainly if that can be achieved with a small amount of maintenance. The main thing is the time to get up to full production.

    Best wishes,