Experiences with “carbon farming”; livestock, soil and land use
Dave Stanley is director at e3 and Fellow at the Institute Environmental Management and Assessment.
FCRN: Could you describe your current work and focus?
Dave: I live in south Lincolnshire and operate as an independent adviser, supporting organisations in carrying out sustainability appraisals, management workshops and developing their sustainability strategy and policies. I also run a small herd of Lincoln Red cattle, selling beef directly to the public.
FCRN: How did you get into food and climate research?
Dave: In my career I have been involved in most aspects of project management. However I have always been interested in food and farming. On leaving the Environment Agency 14 years ago I set about achieving my ambition and bought two cows. I progressively built up to 45 head of cattle grazing 80 acres of Grassland. Researching the many problems I encountered with respect to cattle health and fertility, resulted in my current understanding of the critical importance of soil to food and farming, to ourselves and of course its impacts on the planet.
FCRN: What are the aims of your project as they relate to food and the climate?
Dave: It hasn't been so much about a project aim, more an ongoing development of my understanding. I have been aware for many years of the importance of ecosystems in the functioning of the biosphere. The revelation to me has been the importance of soils. There is three times more carbon locked up in our soils than there is in the atmosphere. In respect of climate change, if we are to be serious in our management of the carbon cycle, then soil should, in my view, be the primary focus. The degradation of our soil organic matter, and the huge impact this is having on carbon flows in the atmosphere, biodiversity and even food quality and human health has been largely ignored, or even denied.
FCRN: How have you worked with livestock and climate?
Dave: When I started with the cattle, I was determined to manage them on as close as possible to a zero fossil fuel input system. This meant just feeding them grass. I ended up renting grazing from ten different locations. A lot of the fields consisted of coarse grasses, nettles, thistles and docks as a result of the use of nitrate fertiliser. I had all sorts of problems relating to lack of fertility, calving difficulties, and the beast just not thriving.
I took the obvious step of endeavouring to return this poor quality grazing land to good quality meadow. This is not an overnight operation! But I also dug deeper and analysed the soils for 15 trace elements. Fortunately at this stage I also measured the carbon levels in the soil.
FCRN: How was this done?
Dave: For each of the three fields soil samples that were analysed by Lancrop Laboratories to identify any imbalance of 15 essential trace elements. The soil carbon was analysed using the loss on ignition test. Subsequently a specialist company FieldScience produced a tailor-made dusting of the deficient trace elements which was then applied using a slug pelleter on a quad bike. Depending upon the soil type this treatment can last up to 5 years, during which time the soil ecosystem should be re-establishing itself.
FCRN: What inputs did you use?
Dave: In addition to the initial application of tailored trace elements to each of the 3 fields, 150 t of sewage sludge was applied to the arable field prior to seeding with a Meadow mix. Subsequently there have been no further inputs whatsoever. Weeds such as creeping thistle and nettles have been managed by mowing and selective cutting. At the end of each winter seed was collected from the feed rail in the cattle shed and hand broadcast into the field that only had coarse grasses. This method has proven to be very successful and considerably less effort than the accepted method of spreading hay.
FCRN: Have you measured the N20 emissions arising from the use of inputs - both the mineral and the organic fertilisers?
Dave: Measuring nitrous oxide emissions in an open field operations such as this would be extremely challenging - and costly. Nitrogen emissions are interesting, but somewhat controversial - take the counting of nitrous oxide emissions from legumes which a grassland ecosystem has always emitted. Addressing the carbon cycle is a fairly straightforward issue compared with the nitrogen cycle. In my view the latter is very strong on assertion and short on critical analysis, particularly with respect to the use of chemical nitrogen as a fertiliser. For instance the disruption to the global nitrogen cycle as a result of the emissions of nitrogen from the use of chemical fertiliser and fossil fuels is of an order of magnitude greater than that of the emissions of our Carbon Dioxide to the carbon cycle. Which should be the policy priority?
Furthermore the use of nitrogen fertiliser can be correlated with a significant reduction in soil organic matter - and hence carbon emissions to atmosphere, along with the loss of our soil's natural fertility. The fact that crop yields in UK have for the last 15 years plateaued, along with the fact that soil organic carbon has, for the present, bottomed, invites a credible explanation.
The farming practices I adopted were intended to mimic, insofar as it was possible, a natural grassland ecosystem. It is virtually a closed loop operation (excepting sun/rain) with minimal external inputs; these largely consisted of diesel for the operation of the tractor. Diesel consumption per unit output was recorded - on farm at about 10 gallons per steer slaughtered. Add a couple of gallons for an excessive run to a centralised abattoir and back, plus returning the carcass to the local butcher, add say, another 10 gallons, for the incineration of that which should have been turned glue etc, plus hides to India etc and we still have a figure (25 gallons) that is only 10% of some of the figures quoted for the "commercial" production of beef.
Any emissions of nitrous oxide, and methane for that matter, would be those that would have been naturally occurring in a grassland ecosystem, and therefore have no net negative impact on Climate Change.
Ten years on the difference is dramatic. The cattle are healthy, fertile and calving in a three week period in May. The reinstated meadow land in summer is a joy to see, along with all the wildflowers and the biodiversity that is riding on the back of it. Having tasted grassfed-only beef, our customers won't go anywhere else, particularly when they become aware of the health and Omega 3 issues in meat relating to the way that livestock are fed.
FCRN: And what happened to the carbon that you measured in the soil?
Dave: The soil carbon sequestration rates in the grassland grazed by livestock that I have measured are amazing. The actual rate of sequestration in a particular field appears to vary according to past management practices. By this I mean that the actual rate of carbon sequestration would appear to vary according to a wide range of factors including soil type, moisture levels, health of the soil ecosystem, which would be a function of past management practices - whether nitrate fertilisers and pesticides have been applied or not. I have recorded between 3 and 5 tonnes of carbon (note) per ha per year. This is much more than Defra or the IPCC reckon.
FCRN: The accepted figure is around 200-500 kg per hectare per year for grassland (according to CCAFS). If these carbon sequestration figures are correct, this has important implications for the way we might farm. What do you consider to be the reason for this very high sequestration rate?
Dave: I don't claim to be a soil scientist. From observation and the research that I have done, the key factor appears to be soil organic matter. Most gardeners are well aware of the benefits of increased yields, plant health and improved taste arising from incorporating compost into the vegetable patch. Yet with agriculture generally this benefit is largely ignored. Indeed, farmers having manure on a farm results in them attracting the attention of the regulators.
A healthy soil and aboveground ecosystems are critical to having thriving soil organic matter. Improving the soil organic matter also means you increase the rate of carbon sequestration. Crop rotation, grass and clover leys, livestock and the use of chemical nitrate fertiliser and other pesticides all feature in this equation. With the effective functioning of soil organic matter and carbon sequestration, it would appear that there is a synergistic effect, and that the whole is greater than the sum of single land management actions.
FCRN: What are your plans for the immediate future as regards this work?
Dave: All this work has been self funded so far. However I have gained sponsorship from a laboratory in respect of future soil analysis. I have found a number of locations, where over the last 20 years there has been substantial land-use changes (into or out of grassland, woodland etc), only yards apart on the same soil type. Subject to land owner approval, I intend to research the implications of these changes in terms of soil organic matter and carbon over the period.
FCRN: What do you see as the big questions for the food climate research community at the moment?
Dave: I see a number of interrelated issues.
First has to be that of giving due attention to the critical importance of our soils and its role in regulating the atmosphere, maintaining ecosystems, optimising crop yields and also that of delivering the nutrient quality to our food that is essential for maintaining our health. Second is realigning our focus from just consideration of greenhouse gasses to that of managing the whole carbon cycle - and soil has a huge role to play here. Third would be addressing the whole life costs of our food production system - not just carbon footprinting. Adding up the greenhouse emissions arising from food production is becoming quite fashionable, albeit an end of pipe activity. There is rising concern over the limitations in the very near future on the inputs to the food production system, for instance: water, nitrates and phosphates etc.
The current linear extract >use > dump approach to food production negatively impacts on our ecosystems - particularly soil - causing significant degradation and loss of our natural capital, typically reported by the rapid decline in farmland birds. We should be considering the inputs and outputs, along with the associated negative environmental impacts at every stage of the whole life cycle of our food production system–agriculture, food processing, distribution, retailing, consumption, and "waste disposal" - the latter should involve the closing of the loop by returning the organic material to our soils whence it came. Rather than "sustainable intensification" which amounts to business as usual - just do it harder with "sparing" land for "conservation", we should be seeking the optimisation of the whole food cycle of farming and food production for healthy wholesome food for a growing population, carbon sequestration and ecosystem enhancement.
Last but not least - let’s make sure we join up the thinking! Food production should not be seen as just another economic activity like car manufacturing and banking, but to be an integral part of ecosystem biosphere management. We should be living (sustainably) off nature's interest arising from photosynthesis, rather than the short-term erosion of capital by the consumption of fossil fuels and mined fertilisers which is manifestly unsustainable in the long term. In short we should be adopting cyclical "ecosystem" thinking.
FCRN: What milestones might we look for?
Dave: I have been filming as I've gone along. All of the above, along with the supporting data and references, has been incorporated into a video briefing. Following on from this I have spoken at a couple of national conferences this year on the topic of "carbon farming", and a further film on the topic has been produced by Graham Harvey - author of "The Carbon Fields” on PasturePromise TV - "Who says cattle are criminals?".
The video briefing is called "Climate Change - the answer is Bullocks" can be found at http://www.tochallengethethinking.co.uk/video/
Since this interview Dave has been awarded the Lincolnshire Environmental Award for Farming.