Which Way for Sustainable Development?

Anthony Trewavas FRS

Abstract

Integrated farm management is currently the most sustainable form of farming to lead the UK into the 21st century.

What is sustainable development?

The title reflects the known conflict between economic growth and the natural environment. Industrialisation, increase in wealth, population growth and farming have consequences for the natural environment. Sustainable development is a compromise position between environmentalists who never cost environmentalist policies and economists who perhaps know the cost of everything and the value of nothing (Carley and Christle 2000; Clark 1995; Goodland 1995 ; Nelson, 1995; Simon 1996). However in another sense the term means little; who, for example, is for unsustainable ruination?

A definition by Brundfland in 1987 "Development that meets the needs of the present without compromising the needs of future generations" has run into difficulties because it has been interpreted as extreme preservation. For example UNESCO stated that "Each generation should leave undiminished all the species on the earth", an unrealistic expectation and also one which places the natural order as more important than mankind. Dominant species like our own have always driven other species to extinction. But mankind is currently unique in attempting conservation of many animal and plant species. An alternative definition by the economist, Solow, “not to leave the world as we found it in detail but to leave for the future the option or capacity to be as well off as we are” is perhaps more realistic. Whatever perspective is adopted, farming is right in the middle of it.

Farming must be efficient to best preserve natural environments

Farming is the largest land management system on earth and in total occupies one third of the present land surface although much of this is rough grazing on poor soil. Farming has used an estimated one half of the quality soil on the earth, the remainder is under tropical forest and attempts to use it for farming will lead to obvious knock-on effects on global warming (Gregory et al., 2002). As populations continue to rise, pressure will build on these forested areas of the world. An obvious and crucial aspect of sustainable development is that farming should be as efficient as possible, to spare further wilderness encroachment, but be compatible with good environmental and landscape conservation (Trewavas, 2001). Those at this conference will thus recognise the origins of integrated farm management (IFM).

Is organic farming more sustainable?

Some environmentalists have claimed that organic farming is the sustainable future. And organic associations have often attacked other forms of farming with this assertion. But is organic the best compromise between economic and environmental views? Science says otherwise. Soil Association regulations require frequent additions of manure or green manure in the belief that these are essential to maintain plant health and crop yields. However fields at Rothamsted experimental station have grown winter wheat in the Broadbalk experiments continuously for 160 years (Rasmussen et al., 1998). In one field only minerals have been added and in the other only manure. Throughout that period the yields (now currently over 6 tonnes/ha and increased to 8 tonnes with a single rotation in a third field) have been identical. Furthermore nitrate run off was worse from manure (Goulding and Poulton, 2002). While no-one would recommend continuous winter wheat without organic material because of possible erosion (and general maintenance of soil quality is certainly preferable), it makes the point that Soil Association claims do not have the sound basis that is often asserted. Organic farming is less efficient, average UK yields are 50-70% conventional farms (Leake, 2000). When measurements of environmental parameters take account of yield, many supposed benefits (e.g. nitrate run off) of organic farming simply disappear. However the inspector system that organic associations use is commendable and should be extended although in different ways to other forms of farming.

Organic associations claim their agriculture is chemical free. However organic regulations list 33 chemicals that can be used (UKROPS). And although organic associations blame conventional agriculture for nvCJD through meat consumption, organic regulations also list blood, bone and meat meal as approved organic additives to soil. The stability of the BSE prion in soil is unknown but its resistance to many treatments should give cause for concern for its previous use.

Is organic natural?

In forests, the fall of individual old trees leaves a gap where light penetrates to the soil surface and there is an accompanying flush of nitrate and water in the soil. Many weed seeds use these signals of nitrate and light to programme germination. If left, the process of FenCarr succession leads eventually to shrubs and recovery of eventual forest in 20-40 years. Agriculture mimics this process of ground-clearing by actively removing trees and planting crop seeds whose ancestors were domesticated weeds but with the nitrate and light requirements removed by breeding. However the further processes of succession are actively and annually prevented by herbicides or the plough. No form of agriculture is therefore natural and the rejection of nitrate application in organic farming is definitively unnatural. On that basis conventional farming and IFM is nearer nature.

Health consequences of higher priced food

But the much higher cost of organic food and the consequences that follow from that cost are simply ignored by both environmentalists and organic associations. About 200 epidemiological investigations have clearly established that a diet high in fruit and vegetables cuts cancer rates approximately in half and for virtually all cancers (Ames and Gold 2000). But the Food Standards Agency has indicated that only 25% of us actually eat the minimum daily fruit and vegetable portions for protection against cancer. Price determines consumption (Lomborg, 2001). Pressure on the public to buy organic food from unsubstantiated claims about either the health or the safety of the product (Trewavas, 2001) will only ensure that when purchased, less will be consumed. The consequence: more premature cancer, more premature death (Ames and Gold, 1999). For the 75% already at higher cancer risk, higher priced products will not encourage them to change their poor dietary habits. The Food Standards Agency has published figures indicating that whereas 110,000 UK citizens die from poor diet, none die from pesticide residues in food.

Campaigns against trivial residues in food threaten UK health

Even more significant is that the 200 epidemiological investigations used conventionally-farmed fruits and vegetables containing, of course, synthetic pesticide residues. The more fruit and vegetables you eat (and thus more pesticide residues), the healthier you become. The frequent, ill-informed campaigns against pesticides that instead imply danger to consumer health can be seen to be totally the reverse of logic. And since giving up pesticides would increase the price of fruit and vegetables substantially, such campaigns if continued (by Friends of the Earth for example) will actually and irresponsibly damage public health not improve it. For example the Soil Association recently claimed that lindane, an organochlorine pesticide would induce breast cancer based on no evidence at all; a view completely and roundly contradicted by medical doctors and experts (Committee for Carcinogenicity of Chemicals in Food, Consumer Products and Environment. 1999). Lindane is classed as a xeno-oestrogen. Crop plants make many xeno-oestrogens and our daily consumption of these is millions of times higher than any synthetic organo-chlorine residue. Environmentalists of all persuasions should leave toxicology to those that understand it and cease trying foolish scare tactics to favour organic farming. Now that organochlorines have been found to form naturally in decaying plant material and in very substantial amounts (milligrams/kilo: Myenini, 2002), questions about the safety of green manure rotations (used frequently by organic farmers to improve soil rotation but which leave decaying residues in the soil) must and have already been raised. Consistency should then lead environmentalists to demand bans on green manure! In my view organochlorines have never represented any danger to human health. And the control of malaria by DDT is of enormous benefit to mankind saving millions of young lives (Simon, 1996). Quite clearly we (and all of nature) have always been exposed to such chemicals.

Life expectancy has continued to increase linearly as it has done from 1840 onwards (Oeppen and Vaudel, 2002). Consumption of fruit and vegetables has doubled since the war and stomach cancer rates correspondingly have fallen by 50%. The use of pesticides has clearly benefited health. UK centenarians are now ten times more common than in 1950. Overall cancer rates continue to decline and most particularly in the young and middle aged where anything untoward in diet would reveal itself (Coggon and Inskip 1994; Doll 1992). Pesticides used responsibly, as in IFM, keep fruit and vegetable prices low. That is the healthy way forward and these data rebut pesticide critics who deliberately ignore benefits.

99.99% of our daily dietary pesticide consumption comes from thousands of natural chemicals present in all foods, organic and conventional alike, and made by plants to inhibit insect predation (Ames and Gold, 1999). Some of these natural pesticides hover on the brink of being directly poisonous as occasional plant breeding accidents have amply shown. Organic products are not free of synthetic pesticide residues and contain about half that of conventional food. The consumer has to decide whether that is worth the extra price to reduce a non-existent danger by half.

In every respect IFM is more sustainable

In landscape, animal welfare, and whole farm attitude, IFM matches anything organic farms have to offer. The LEAF audit (Drummond 2000; www.leafuk.org) is searching but throws responsibility, as it should, onto the shoulders of the farmer to carry through. In the end high managerial standards and skill are what makes for good farming.

Comparative studies using conventional, organic and IFM methods performed at the same farm and using the same farmer for a joint period of 17 years have substantially proven the benefits of IFM over the other kinds of farming. The experiments at Boarded Barns, Ongar, Essex were revealing. 80% biodiversity was found in the margins and hedgerows. IFM keeps similar margins as organic farms and maintains hedgerows. However the kind of crop in the field made a bigger difference to predatory beetle numbers than farming method. Small mammal numbers were similar on organic and IFM fields but predatory mites higher in IFM fields.

But ploughing is the most damaging thing that can be done to soil and is generally used to eliminate weeds unless herbicides are properly used (Clarke 2000). It is in the development and use of No-plough (conservation) agriculture that IFM really scores. In No-plough agriculture, weeds are controlled by herbicides and crop residues are simply left on the surface or minimal tillage used to incorporate them into the soil surface layers. Quite rightly conservation agriculture claims to mimic the natural turnover of annual material of meadows. Organic farms suffer considerably from weed problems because herbicides are (illogically) rejected. Compared to a ploughed organic field, No-plough (conservation) IFM reduces fossil fuel use and greenhouse gas emission to one third, bird territories, earthworm and other soil invertebrates (including pest predators) soar, nitrate run-off is cut by half and soil erosion all but disappears (Jordan et al., 2000; Gregory et al., 2002; Higginbotham et al., 2000; Leake 2000). Most crucially the soil becomes a carbon sink, a process reversed by ploughing (Leake 2000).

Integrated Pest Management reduced pesticide inputs by half and improves net margins (Ogilvy et al., 2000). It is here that managerial skill is most needed because an assessment is needed as to when economic damage may or may not occur and thus when to use pesticide applications. The LEAF audit requires farmers to return excess pesticides to the manufacturer for proper disposal rather than down the drain. The flexible policies of IFM are far more sustainable than the rigidities of organic regulations, which have to optimise yields within self-imposed constraints. IFM keeps prices low of critical importance for consumer health. But the continually changing future requires flexibility to survive. IFM is the more obvious candidate to take sustainable farming forward into the 21st century.

References

Ames BN & Gold (1999) In, Fearing Food (eds J Morris & R Bate) Butterworth-Heinemann Oxford. pp 19-38.

Ames BN & Gold LS (2000) Mutation Res. 447, 3-13.

Carley M & Christie I (2000) Managing Sustainable Development. Earthscan London.

Clark JG (1995) Annu Rev Ecol System 26, 225-248

Clarke JH (2000) Aspects Appl Biol 62, 221-231.

Coggon D & Inskip H (1994) British Medical Journal 308, 705-708.

Committee on Carcinogenicity (1999). Department of Health (http://www.doh.gov.uk/coc/index.htm). Annual Report of the Committee on Toxicity, Mutagenicity, Carcinogenicity of Chemicals in Food, Consumer Products and the Environment (http://www.doh.gov.uk/coc/1999ar.pdf [pdf]), pages 62-71.

Doll RM (1992) American J Public Health 82, 933-940.

Drummond C (2000) Aspects Appl Biol 62, 165-173.

Goulding KWT & Poulton P (2002) The Broadbalk Experiment. Data from Keith.Goulding@bbsrc.ac.uk.

Goodland R (1995) Annu Rev Ecol Syst 26, 1-24.

Gregory PJ Ingram JSI Andersson R et al. (2002) Agriculture, Ecosystem and Environment 88,279-290.

Higginbotham S Leake AR Jordan VWL & Ogilvy SE (2000) Aspects Appl Biol 62, 15-21.

Jordan, VW Leake AR Ogilvy S & Higginbotham S (2000) Aspects Appl Biol 62, 239-244.

Jordan VWL Leake AR & Ogilvy S (2000) Aspects Appi Biol 62, 61-67.

Leake AR (2000) Aspects Appl Biol 62, 253-260.

Lomborg B (2001) The Skeptical Environmentalist. Cambridge University Press.
(Click here to see a review on Land-Care)

Myneni SCB (2002) Science 295, 1039-1041.

Nelson RH (1995) Annu Rev Ecol System 26, 135-154.

Oeppen J & Vaupel JW (2002) Science 296, 1029-1031.

Ogilvy SE Jordan VWL Leake AR & Higginbotham S (2000) Aspects Appl Biol 62, 231-238.

Rasmussen PE Goulding KWT Brown JR Grace PR &Janzen HH (1998) Science 282, 893-896.

Simon J. (1996) The Ultimate Resource. Princeton University Press. Princeton.

Trewavas AJ (2001) Nature 410, 409-410.

Trewavas AJ. (2001) Plant Physiol. 125, 174-179.

UKROPS. United Kingdom Register of Organic Food Standards

Anthony Trewavas is a Professor at the University of Edinburgh. Plant Biologist. 200 published papers. Member Academia Europea. Fellow of the Royal Societies of London, Edinburgh and World Innovation Foundation. Life member (by election) of American Society of Plant Physiologists.

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