Dear George,
I am a long-standing fan and an admirer of the stances you have adopted on many key environmental issues, so I hope you won't mind if I take public issue with you on some of the points that you made in your recent Guardian article about Allan Savory and his advocacy of holistic grazing management systems.
I should first declare my various interests:
- I am a farmer of ruminants myself, with 85 Ayrshire milking cows, plus their various offspring on my mainly, but not exclusively, grassland farm in West Wales, (which you visited very briefly back in 2007);
- I have a long-standing interest and engagement with developing improved systems of pasture management, although none of these experiments have been monitored; and,
- while you were in the library checking out the science on Savory's claims, I was attending and speaking at the Savory Institute International Conference in London last week, which provided the hook for your Guardian piece.
As I understand it, your key critique of Savory is that he is has made a series of unsubstantiated claims relating to the capacity of holistic grazing management systems (which you referred to as Intensive Rotational Grazing, or IRG), not only to increase ruminant stocking densities but also to build soil carbon in the form of stabilised organic matter.
What clearly rattled you most was his assertion that were such systems were to be applied on a global scale, they would have the potential to sequestrate a significant percentage of the current levels of CO2 in the atmosphere.
In summary, my response is that whilst accepting your points about the relative scarcity of the scientific evidence supporting his claims, and the possibility that he may have been over-claiming on his assertion that such methods could have the capacity of "reducing CO2 to preindustrial levels", I still think he may well be right on both counts.
The reason I particularly wanted to write to you about this is because I am very worried about the anti-ruminant bandwagon, which seems to be gaining momentum daily, based on three assertions, all of which need to be challenged: the inefficiency of feed to meat conversion, the unhealthy nature of red meat, and methane emissions.
You may be aware that my colleague Richard Young has been countering some of these charges in a separate series of articles, but for the purpose of this exchange, I shall focus on my assertion that ruminants will need to play a central role in the development of more sustainable food systems. This is because they alone are able to digest and turn into food the cellulose-based plant material, which constitutes the fertility building phase of sustainable, rotational farming practice.
This unique capacity is very important, partly because if the world is to wean itself off our current addiction to nitrogen fertiliser, then producing food from arable land during its fertility building phase, which in most cases will constitute a mixture of legumes and grasses, will be of critical importance in developing strategies for feeding a peak world population.
Another, and possibly even more important, factor relates to so-called "rangelands" the vast areas of predominantly grassland ecosystems, which cover a quarter of the world's land area and on which the ruminant animals that form the basis of Savory's observations have evolved and coexisted over millennia.
I am no great expert in the management of these areas, but I did have the very good fortune to spend some time in northern Kenya two years ago with the nomadic pastoralists of that region. These tribes subsist almost entirely upon the products of ruminants and their grassland management practices, which involve seasonal grazing of herded animals ranging over very large areas seem to demonstrate Savory's theories very well, so long as they remain undisturbed by the devastating intrusion of land grabbing.
Turning to somewhat safer home ground and using the example of my own farm, at any one time around 70% of the total area is devoted to grassland, mostly in the form of permanent pasture, with the balance in short term leys, building fertility for arable crops, which in my case have been vegetables, oats and peas.
Influenced by the ideas of Allan Savory and other advocates of holistic grazing, I have been introducing the basic principles of this approach into my grazing management over the last few years. For clarity, this means dividing my grassland fields into small parcels, often referred to as "paddocks" on which we graze the whole herd intensively for between 12 and 24 hours before moving them on, thus allowing the rapid recovery of the grazed area.
Historically, my practice has been to turn the herd into large fields and either let them roam freely, or "strip graze" it section by section behind an electric fence. To understand why this system is inefficient in Savory's terms, one has to know something about cattle grazing habits. Let's say I turn my entire herd into a 10-acre field, containing a good crop of lush grass, after a period of relatively wet weather, not uncommon in Wales! What the cattle will do, is range over the entire field, taking one bite of the very best grass, then graze it for a second time and so on, until the least palatable grass has been eaten, by which time the field will have been trampled on eight or 10 times, over a period of up to a week.
Under such treatment, the recovery of grass is delayed, partly because of the compaction and soil damage caused by repeated trampling over time, and also because the cows stay on the field for much longer than would be the case in a "paddock" grazing regime.
Interestingly enough, at the Savory conference, I learned of a third reason why such "extensive" cattle grazing systems are not conducive to maximum grass output or building soil fertility. This is connected with the behaviour of plants after defoliation, either by cutting or grazing. Apparently, when a plant is defoliated – a tremendous shock to its system – it exudes a strong pulse of sugary plant sap into its root zone, thus stimulating activity in the symbiotic community of bacteria and fungi surrounding the roots, upon which the nutrition of all plants depend. This gives rise to the phenomenon, which I have often observed, of how a field (or even lawn) which has been cut, recovers amazingly quickly, as evidenced by tender young leaf regrowth of two or three inches in just a few days.
However, when plants are repeatedly grazed after defoliation, apparently this triggers a defensive response, the result of which is that the plant jettisons a substantial proportion of its roots, since such carrying capacity will no longer be required if the plant is unable to regrow.
The combination of my own observations as a farmer and the influences of Savory and others, have been sufficient to result in me deciding to redesign my grazing systems over the last couple of years, installing the necessary infrastructure for paddock-style rotational grazing, which includes farm tracks, water troughs and electric fencing.
As with Savory, my initial observations of the impact of these changes are unscientific and anecdotal, but nevertheless I can say with some confidence, after having been farming without any nitrogen fertiliser for 41 years, that the introduction of holistic grazing management has the potential to further increase the ruminant carrying capacity of my farm from the already strong base I have achieved through many years of biological soil management.
This takes me back to my earlier point, which is that in my opinion, holistic grazing management principles have the potential to be applied on all the world's grasslands, both permanent and on the temporary leys which farmers will use to rebuild soil organic matter in a post nitrogen farming regime. Because of this, the issue of whether holistic grazing management regimes can improve ruminant productivity and soil carbon outcomes is of absolute critical importance.
I can imagine in response you might say "show me the science" which would be perfectly legitimate, but before we are able to amass a sufficient body of research to validate the concerns of skeptics, I would urge you to be a little more cautious before you throw this particular grass fed ruminant baby out with the collective bath water of intensive livestock farming.
In that connection, I know you place a lot of importance on validating hypotheses with evidence, but I think it's worth pointing out that we are hopefully emerging from a chapter of agricultural practice which has been based on reductionist science and chemistry and entering a new phase where the informing principles will be related to complexity and biology. In this field, the capacity and track record of practical farmers in making grounded observations about the efficacy of different systems, is not only of greater value, but often more useful than the contributions from the scientific community, who in addition to their attachment to reductionism are often influenced by vested interests.
I won't go into detail here, but suffice to say that agricultural policy and subsequent practice has been massively influenced by the agro-chemical lobby over my entire farming lifetime and I have not always been particularly impressed by the work of the major research institutes due to the aforementioned problems.
Having said that, I do fully accept the need for evidence-based policy and with that in mind, I have done a little trawling through the published studies on the impact of different grassland management systems on soil carbon outcomes, the initial conclusion of which is that there does appear to be at least a reasonable body of evidence indicating that different management practices do impact very significantly, both on stocking capacity and soil carbon.
Hopefully, you will feel inclined to respond to this provocation and continue the discussion, in which case I shall continue to bury myself in the "virtual" library of the internet and supply you with the fruits of my research in a further exchange!
One final point. I know that you are not a great fan of sheep, but it may even be that the application of holistic grazing management principles could have a similarly positive effect on extensively grazed areas, such as the Cambrian mountains, which have undoubtedly been overgrazed in the past, with obvious negative consequences on biodiversity and soil carbon.
I do hope you will find this of interest and look forward to hearing your response.
With best wishes,
Patrick Holden
Chief Executive, Sustainable Food Trust
