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How much land do we need to feed ourselves?

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Is sustainable local food production possible?

April 26th, 2013

by Dorienne Robinson

Dorienne Robinson explores the relationship between land carrying capacity and human dietary requirements in an attempt to answer her own question - could the UK feed itself?

Around 80% of everything we eat comes from other countries

Sometimes it’s impossible to see the ‘elephant in the room’, particularly if that room is full of likeminded, convivial folk all pulling in the same direction, chipping in and working collectively with similar motivations. The room, in this case, could be the times that we live in and the global problems that we and all other species sharing this planet with us are facing.

Climate change, post peak oil and a relentlessly burgeoning population with life style aspirations, well beyond that which nature can sustainably provide, combine to bring us all either to our senses or to the brink of a place and time that could be our undoing.

Being in the ‘room’ can engender a sense of ‘ok-ness’, even a sense of pleasure and certainly, in some cases, feelings of self-righteousness as we all quickly put the world to rights before driving home to go on the internet, watch TV, cook dinner...

As the person cooking the dinner I pondered on the raw ingredients I was using and on how they got to my kitchen. It was then that the full enormity of the situation facing us dawned on me.

We live in a third world country! Around 80% of everything we eat comes from other countries. If the food trucks stop rolling in to restock the supermarkets in our towns and cities we will have nothing to eat! We rely on being fed by countries who can sometimes not even feed themselves and all of whom are going through equally challenging and uncertain times with climate, post peak oil and collapsing economies.

I cast a weary eye over the veg’ patch where there were a few tired kale plants and a rather sad cabbage and suddenly there was the elephant. Not in the room, but in my garden!

How on earth are we going to feed ourselves? How are we going to organise ourselves cohesively to be able to produce the variety and quantity of foods we would need to sustain our population, indeed what should those foods be? Who would grow them? Who would the buck stop with if the crops failed? Who will harvest them and get them to market and where will those markets be?

After a brief moment of panic and several months of research I felt I had come up with the beginnings of a solution. I developed a way of calculating the dietary and land needs of any given community, to see if it would be possible to be completely self-sufficient in food.

Here it is and if anyone would like to apply it to their village, town or city and let me have their results I would be happy to develop a map of the UK indicating the land we would need in order to feed ourselves to see if it is possible.

The first step is to calculate the head of population in your community. This could be current or at a predicted time in the future. Population statistics are available from your local county council who update information after each census, a census usually being conducted every ten years.

Now you have to decide what a good basic diet will consist of. I chose to look at work previously done by Simon Fairlie of ‘The Land’ magazine. Simon had calculated land take for a range of diets including: Chemical with Livestock; Chemical Vegan; Organic Vegan; Organic Livestock; Livestock Permaculture and Vegan Permaculture.

When trying to decide which of Simon Fairlie’s models would be the best it should be remembered that fossil fuel depletion would mean an end to chemical fertilizers and pesticides, or at the very least make them so expensive that they are no longer viable. It would seem reasonable, then, to ignore ‘Chemical with Livestock’, even though it appears to feed a lot of people per hectare. Equally ‘Chemical Vegan’ must be eliminated for the same reasons.

It is extremely unlikely that any community would accept being completely vegan, even though both options clearly show that vegan diets can support between 8 and 8.5 people per hectare and that dietary needs can be met without animal inputs.

This leaves ‘Organic with Livestock’, and, ‘Livestock Permaculture’. According to Simon Fairlies calculations ‘Livestock Permaculture’ will feed 0.5 more people than Organic and does it on less land, leaving more for wilderness, recreation or simply land in reserve.

So basing a basic diet on Livestock Permaculture you then need to design a weeks menu for one person, e.g.

  Mon Tues Wed Thurs Fri Sat Sun
B’fast 2Scrambled eggs on 2 slices of toast Toast, butter and a fruit preserve Bubble and squeak. Porridge Mushrooms on toast Pancakes with fruit preserve Mushrooms, potato cakes, tomatoes, toast
Lunch Chicken soup and bread Broad bean pate, toast and seasonal salad Ploughmans Onion tart and seasonal salad. Parsnip and apple soup Sweetcorn pasties. Roast chicken, Seasonal vegetables
Dinner Vegetable chilli with spelt rolls and seasonal salad. Apple crumble Cauliflower pie with roast potatoes and seasonal raw salad. Stewed pears Raw nut savoury pudding with steamed seasonal vegetables and spelt rolls. Blackberry and apple pie Mutton stew with potatoes and kale. Jam sponge Bean layer pie with cabbage, potatoes. Plum cake Homity pie with kale and seasonal vegetables. Rhubarb crumble Jacket potatoes with cheesy leek.

The next step is to break the weekly menu down into weights and quantities for one person for one week and then one week for the total predicted population. Multiply this by fifty-two and we have some idea of the quantities needed annually.

My calculations have been done for Powys where I live and which has a total population prediction of 146,107 by 2020.

Ingredient Quantity per person Weight per person Weight/Quantity for 2020 population of Powys for 1 week Weight/Quantity for 2020 population of Powys for 1 year
Eggs 4   584,428 7,013,136.00
Bread 2 x 500g loaves 1kg 146,107kg 7,597,564kg
Butter 1 250g 36,526kg 438,312kg
Jam   100g 14,610kg 759,720kg
Oats   200g 29,221kg 1,519,492kg
Potatoes   2kg 292,214kg 15,195,128kg
Cabbage 1   146,107 7,597,564.00
Mushrooms   500g 73,053kg 3,798,756kg
Milk   1litre 146,107ltrs 7,597,564ltrs
Tomatoes   500g 73,053kg 3,798,756kg
Chicken .25   36,526 1,899,352
Mixed salad leaves   200g 29,221kg 1,519,492kg
Broad beans   300g 43,832kg 2,279,264kg
Cheese   100g 14,610kg 759,720kg
Onions   2kg 292,214kg 15,195,128kg
Garlic 2 bulbs   292,214 bulbs 15,195,128
Parsnip 2 500g 73,053kg 3,798,756kg
Cooking apples   1kg 146,107kg 7,597,564kg
Sweetcorn   50g 7,305kg 379,860kg
Swede .25   36,526 1,899,352
Leeks   400g 58,442kg 3,038,984kg
Spelt rolls 4 500g 73,053kg 3,798,756kg
Flour   500g 73,053kg 3,798,756kg
Cauliflower .5   73,053 3,798,756.00
Chilli pepper .25   36,526 1,899,352.00
Carrots   400g 58,442kg 3,038,984kg
Kale   500g 73,053kg 3,798,756kg
Pears 1 150g 21,916kg 1,139,632kg
Rhubarb   150g 21,916kg 1,139,632kg
Blackberries   50g 7,305kg 379,860kg
Plums   75g 10,958kg 569,816kg
Mutton   100g 14,610kg 759,720kg
Pork   100g 14,610kg 759,720kg

The next task is to calculate the land needed to produce this food and don’t forget that this is for a community with a population of around 146,107, equivalent to an average UK city.

I have calculated the land take for animal production to include food, grazing and shelter and these findings are available as individual breakdowns on request as there isn’t room to reproduce them here. Equally, the calculations for vegetable production are based on personal experience of field scale growing.

Projected figures for land take based on vegetable, cereal, poultry, pig and dairy production

Occupation Land area needed in hectares
Vegetable production 634.92
Cereal production for direct human consumption 44.44
Cereal production for chickens 3,466.0
Housing chickens 8,808.0
Cereal production for pigs 16.88
Housing pigs 37.640
Dairy production 4,087.324
Housing for dairy cattle 8,268.75
Total 25,363.954 hectares

The table above indicates that to feed the population of Powys with basic staple vegetables for one week will require 12.21 hectares (30.17 acres) of land. To feed the population for a year would take a maximum of 634.92 hectares, (30.17 x 52), but as with care the land would be able to produce more than one variety in a year if careful crop planning and rotations are observed, so the actual land use could be slightly less in reality. For many of the root crops to be available all year round appropriate storage methods will be needed. Storage needs to happen without the use of fossil fuels to be sustainable, which precludes freezing.

Below are the figures for the land needed to feed the major centres of urbanisation in Powys.

Town2001 population 2020 population Land needed in hectares
Llanfyllin 1,616 1,858.4 232
Llanfair Caereinion 1,400 1,610 201.25
Welshpool 6,269 7,209.35 901.16
Machynlleth 2,000 2,300 287.5
Newtown 10,783 12,400.45 1,550.56
Llanidloes 2,314 2,661.1 332.63
Rhayader 2,075 2,386.25 298.28
Knighton 3,000 3,450 431.25
Llandrindod Wells 5,000 5,750 718.75
Presteigne 2,191 2,519.65 314.95
Builth Wells 2,352 2,704.80 338.10
Llanwrtyd Wells 700 805 100.62
Hay on Wye 1,846 2,122.90 265.36
Talgarth 1,650 1,897.50 237.18
Brecon 7,901 9,086.15 1,135.76
Crickhowell 2,800 3,220 400.00
Ystradgynlais 2,543 2,924.45 365.55

This exercise is designed to help communities identify their land need for food security in whatever timescale they choose, however there are still a series of issues and discussions to be had.

To enable a livestock permaculture mode of food production zoning needs to happen around centres of urbanisation. This means that all sensitive crops and polytunnels happen immediately outside the town/city/village so that they can be tended regularly. The next zone has root crops and fruit bushes, orchards and chickens, etc. needing less attention and is followed by cereals and grains. The final zone is woodland and wilderness where the animals for meat production can roam.

If we identify the land take around our communities that is needed to feed us in this way then how do we join it up? How do we approach landowners and farmers to start discussion on this new way of producing food and how do we deal with the influence on production in this country by European subsidies?

I don’t know. Please think about it and send comments back to me and if you have any difficulties or questions with using my figures please email me: dorienne@headweb.co.uk

 

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