Environmental Report

...THE REPORT BELOW WAS PREPARED OVER A YEAR AGO NOW (Nov 2008). I'LL POST AN UPDATED REPORT AS SOON AS I CAN (SOMETIME IN 2010 HOPEFULLY!) - Chris... 

Vallis Veg started in November 2007, delivering its first veg boxes on 19 June 2008 . Since then we’ve grown about 2 tonnes of food on our site, and delivered 1087 boxes as at November 2008. This report briefly analyses our activities in terms of the ‘triple bottom line’ of environmental, social and economic performance. We do stress that these figures are approximate at best – even sophisticated environmental accounting relies on guesswork, and we don’t have the resources for more than a few ‘back of the envelope’ calculations.

  Environmental performance: carbon emissions associated with fossil fuel use and other human activities are causing global climate change, so businesses are increasingly trying to calculate and minimise the ‘carbon footprint’ of their CO₂ emissions. We estimate that our delivery system produces about 1kg of CO₂ per box. This compares favourably with other schemes, whose reported footprint can be over twice as much, although it’s important to bear in mind that figures aren’t always strictly comparable because of different methodological assumptions. Putting things another way, our delivery system is carbon neutral if we save somewhere between 1 in 2 and 1 in 3 of our customers from a 3km round trip to the shops in a family car.

  These figures don’t take account of the emissions associated with actually growing the veg, which would be a very complex calculation. We have, however, estimated the amount of energy we’ve used in producing the veg we’ve grown (both directly & indirectly in the timber, metal, & plastic on our site) as compared to the calorific energy produced in the veg. This works out at about 2.6MJ of energy used and 2.9MJ produced, suggesting we’re in energy credit – not bad for our first year when figures of 10 times more energy input than output have been quoted for conventional farming.

  Other environmental indicators such as habitat preservation and biodiversity are harder to quantify. On our site we have: planted more than 4,000 mostly native trees; preserved and extended hedgerows; cut meadows late to preserve biodiversity; begun to establish orchards and wetland habitat; and used no artificial fertilisers or pesticides, all of which we hope has brought ecological benefits.

  Social performance: we’ve tried to make our land available for community events. For example, we’ve been involved in local permaculture training and have made land available for the ‘Dig With Des’ gardening skills sessions. We’ve hosted a Food Frome garden visit and also an Open Day for our customers. We’re always interested to hear ideas for making our land available for community use.

  Economic performance: the economic ‘bottom line’ for our customers is whether our boxes offer sufficient value for money to keep buying them – we think that they’re competitively priced (see http://www.vallisveg.co.uk/Questionnaire_Feedback.doc), and we’re delighted that many of you have stayed with us. The economic ‘bottom line’ for us is whether we can earn enough money to keep going. It’s too early to be sure! If growers can earn a local livelihood we think it strengthens the economy and food security of the communities in which they live. We hope our box scheme is contributing to this.

  Environmental Performance: The Details

We explain below how we arrived at the figures we’ve just cited for our environmental performance. We’d welcome feedback from customers on ways of improving our reporting.

(i) Calculating the carbon footprint of our deliveries:

We’ve used 85 litres of diesel in getting the veg from the farm gate to customers’ doors between 19 June and 4 December. Much of this diesel is post-consumer cooking oil which does not make a net contribution to greenhouse gas emissions, so in theory we could discount the proportion of our emissions from the biodiesel. There are valid arguments for and against this, but here we assume that our diesel is regular fossil-fuel diesel to give a maximum estimate of our carbon footprint.

  Using a figure of 2.62kg of CO₂ per litre of diesel from Treasury data yields total emissions of 223kg. Dividing this by the 1087 boxes delivered yields a figure of 0.2kg of CO₂ per box for the fuel used in delivering it.

  There are other sources of greenhouse gas emission in our delivery system, of course. The boxes themselves are one – on the basis of 0.4kg CO₂ per box from industry figures and ten uses per box, the emissions associated with our box deliveries to date are 37kg or 0.04kg per box. Our other emissions we believe to be generally quite slight (a bit of lighting and power use on green energy tariffs). However, we do not know the emissions associated with the food that we buy in. Assuming a high figure of 70% bought in food by weight (the true figure is probably less, but the food we do buy in tends to be the bulkier items) and applying the figure that Riverford have calculated for their boxes (less sources of emissions that don’t apply in our case) yields an upper estimate for this portion of our produce of 0.8kg per box. The Riverford figure is a useful benchmark since it is based on in-depth research by the University of Exeter .

  So our total (upper) estimate for our carbon footprint is 1.04kg per box, comparing favourably with other direct delivery schemes, which can be more than twice as much, although it’s important to bear in mind that figures aren’t always strictly comparable because of different methodological assumptions.

  In terms of the fuel used in our deliveries, another way of looking at things is to consider how delivery of the boxes compares to the use of private cars for shopping trips. We produced 194kg of CO₂ in getting food from hub to household. Assuming a 3km round trip to the shops in a small family car producing 0.46kg of CO₂, our deliveries become carbon neutral if we save somewhere between 1 in 2 and 1 in 3 of our customers from a shopping trip.

  (ii) Carbon footprint/energy balance of production.

  The figure above applies only to the distribution of our boxes beyond the farm gate. But there are also emissions associated with growing the food in the first place. Our sense of the research is that this calculation is highly complex and is very dependent upon the nature of the soil locally and the farming practices amongst many other things, so using a general figure from the literature of so many kg of carbon per acre of cultivation would probably be misleading. Also, since people have to buy food from somewhere, the significant figure would not so much be our absolute carbon footprint in kg but our carbon footprint relative to the alternative food sources available to our customers, which is not possible for us to calculate.

  For this reason, we don’t attempt to calculate the carbon footprint of our food production. However, we do know roughly how much energy we’ve used in producing our food, and how much energy the food has furnished. Although the figures aren’t strictly comparable, it could be said that roughly speaking a sustainable agriculture ought to produce at least as much energy as it uses, so we’ve tried to estimate this equation.

  We’ve weighed as best we can the food that we’ve grown this year, the great majority of which has been sold to customers (or eaten by ourselves!) This amounts to a little over 2 tonnes of vegetables altogether. By applying calorific values derived from http://www.weightlossresources.co.uk/calories-in-food/ to the weights of each different type of vegetable, we arrive at an overall figure of 2876 MJ of energy produced so far this year (although this is an underestimate as we have crops in the ground still producing).

  We’ve used about 10l of diesel and 30l of petrol directly in growing this food (tractor, rotovator etc.), which equates to 1320MJ of energy. In addition, there is an energy cost embodied in the metal, plastic and timber that we use to grow the food. We’ve estimated this cost on an annual basis as follows:

Adding this to fuel use yields a total of 2595MJ, suggesting we’re in energy credit – a reasonable effort, we think, for our first year of production, especially when the research literature cites figures of up to 10 times more energy input than output in mainstream farming.

  (iii) Ecology & biodiversity

  There are many other issues that bear upon the ecological impact of farming, but which are generally harder to quantify than carbon footprint or energy balance – things like soil erosion, nitrate runoff and preservation of wild biodiversity. We’re working hard to ensure that our farming is as environmentally responsible as possible. Here are some examples of our activities in these areas:

  *       we use no artificial fertilisers on our crops, and are moving to a system of green manure leys which build soil fertility and preserve soil integrity

  *       we are working to minimise soil erosion through leys and by creating ditches and ponds which control flooding, and also provide more diverse wetland habitats

  *       we use no pesticides on our crops and are attempting to build up natural insect predators of crop pests by providing the relevant habitats for them

  *       we are diversifying the habitats available to wildlife on our land by planting native trees and hedges (more than 4,000 so far), creating wetland habitat, leaving rough field margins, and cutting grass late to encourage wildflowers.