- The Forgiveness of Nature: The Story of Grass by Graham Harvey
Vintage, 372 pp, £7.99, September 2002, ISBN 0 09 928366 2
The Prince of Wales would love The Forgiveness of Nature. The underlying vision is of England on a Saturday afternoon in late summer, the village green bathed in golden light, the groundsman leaning on his roller and puffing on his pipe, milkmaids and strapping young farmers snogging in the grass, Hereford cattle grazing calmly in nearby fields, confident that their softly marbled beef is second to none. This is a story of grass or grasslands in the service of mankind: more specifically, of husbandry and land use in England and Wales from the Middle Ages to the present, punctuated with entertaining digressions on groundsmen’s turf technology and the history of the lawnmower, and firmly rooted in tradition and organic farming. Graham Harvey quite possibly contributes more to agricultural awareness than any other person in Britain. It is through him that many of us learn about rotations with red clover, the pros and cons of subsidies, even the health benefits of conjugated linoleic acids in the milk of cows fed on fresh grass. For Harvey is the agricultural editor of The Archers, with the power to influence demand for organic products and inform supermarket managers’ purchasing policies. Listeners may discern Harvey’s organic sympathies in the storyline of the soap – though there are often counter-arguments for balance, in good BBC style. And grass gets into just about everything in The Archers: even Brian Aldridge’s current infidelity was facilitated by some entrepreneurial agricultural activity in Hungary.
The grass family, Poaceae, is one of the relatively few genuinely cosmopolitan families of plants. Grasses can be found from Alaska to Antarctica, from coastal salt marshes and desert sand-dunes to tropical forests and the Tibetan mountains. Exceptionally speciose (more than ten thousand species have been formally described), they range from tiny herbaceous plants to the giant, woody, perennial bamboos of China’s western forests. They dominate the natural landscape in the prairies of North America, the steppes of Central Asia, the savannahs of Africa and South America; in total they cover about a quarter of the world’s land surface, and probably account for a disproportionate 10 per cent of the biomass of land-dwelling plants. Wherever people have settled down to manage the land, grasses in the form of crops or animal forage have been key to its transformation. The cultivation of three grass species alone – wheat, rice and maize – has been hugely influential in the development of human society, in many periods accounting for more than half the dietary intake of protein. (In this engaging but lopsided book, Harvey doesn’t bother much with grain crops, their breeding, history or influence.)
Grassland in Britain and Europe is generally not an aboriginal vegetation: its presence and form is determined – unlike the prairies and steppes and savannahs – by human intervention rather than soil and climate. Its presence is a result of the clearing of forest and woodland to make way for arable land and pasture. The rich mix of plant species – not just grasses, but all manner of herbaceous plants – characteristic of ‘traditional’ pastures and meadows sprang chiefly from the open vegetation of forest glades, riverbanks and heathlands. Grasslands spread with the onset of sheep farming and with the cutting of hay for winter forage. The introduction of the grass ley, in which a mix of grasses and nitrogen-fixing legumes were sown in rotation with arable crops to restore fertility on a roughly triennial cycle, was at the heart of the agricultural revolution of the 16th century, and persisted for three hundred years until the introduction of inorganic chemical fertilisers began to short-circuit the managed fertility cycle.
Grasses themselves are a relatively recent arrival on the evolutionary scene. The first fossil grasses turn up in the geological record at almost exactly the same time – 55 million years ago – as the first fossil primates and horses, ten million years after the meteorite impact that disposed of the dinosaurs, and nearly a hundred million years after the first flowering plants. Their subsequent diversification and spread was promoted by a happy combination of environmental and biological circumstances; although, as usual in evolutionary histories, cause and effect are hard to disentangle. The development of seasonally dry climates reduced the extent of forests (one of the few habitats where grasses fare poorly) and opened up great plains where grasses and their associated fauna (grazing ungulates, hoarding rodents) became locked into a co-evolutionary arms race. Teeth toughened and stomachs multiplied as the grazers evolved to cope with grasses’ siliceous defences; grasses developed an entirely new biochemical pathway for photosynthesis that was better suited for growth and survival in the new climates. With a physiological predisposition to grow back after being nibbled to within millimetres of the ground, and numerous ways of surviving heat, fire, drought, chewing and trampling, grasses came to hold sway over vast tracts of Africa, Central Asia and North America. Seeds that were blown on the winds, stuck to the hooves of large herbivores, or dropped and forgotten by hoarding rodents, further aided their dispersal. And the ability to spread vegetatively, as well as to reproduce sexually, helped them to establish, persist and compete efficiently with other plants.
Many of these features are key to the development of a healthy sward, and have been exploited by generations of groundsmen and gardeners in the pursuit of leisure and sport. British football pitches, for example, receive the harshest treatment when grasses can least absorb it: throughout the winter when growth is at its slowest. By the middle of the season – even at professional clubs – large muddy bruises used to form at either goalmouth and in the centre of the pitch, eventually coalescing into a single, glutinous grassless expanse. The World Cup itself was not immune, as we are endlessly reminded by the reruns of those Geoff Hurst goals. It’s hard to forget the misery of having to play on such pitches at school, with your boots getting heavier by the minute as mud accumulated around the studs. The grass had neither the abundance of shoots nor sufficiently cohesive roots to withstand high-speed trampling and sliding tackles. Little attention was paid to drainage, and waterlogging exacerbated the problem. Richer clubs and public schools could afford to reseed or returf in spring; the lower divisions had to leave the turf to recover as best it could. Some of the new money in football (and, much more recently, in rugby) has been spent on better pitches, in recognition of the fact that the speed and quality of the British game wasn’t up to the standards of Southern Europe and South America. Plant breeders have been employed, with remarkable results, to select and propagate varieties of perennial ryegrass that are more resilient, both in the density of their root mat and the quantity of shoots. And these tough new varieties are further cosseted on well-drained sandy soils with – at the glitziest Premiership clubs – underground heating systems that not only protect against waterlogging and frost but also promote growth throughout the football season. Almost as much money is lavished on the pitch as on the star players, and there is scarcely a scar to be seen on these pitches whatever the time of year. Turf-doctoring reached new heights in last summer’s World Cup. The entire pitch in the enclosed, air-conditioned stadium in Sapporo in northern Japan was wheeled outside between matches to imbibe the fresh air and sunlight. (Now that television has pulled the plug on clubs in the Nationwide League, perhaps the mud-pie goalmouth will once more become a familiar sight.)
The success of the turf doctors may owe something to the longest-running experiment in the history of science. The Park Grass Experiment, set up in 1856 by John Bennet Lawes at Rothamsted in Hertfordshire, has now been running more than five times longer than its nearest rival, and still yields results of use to plant ecologists. The original object was to assess the effects of different fertilisation regimes on a sward of grasses and herbs, and to investigate how these effects varied over long periods. Lawes laid out square plots several yards across, each of which received different inputs of fertilisers and manure. The controls and replications of treatments were haphazard, but the Park Grass Experiment quickly provided the first strong indication that the application of chemical fertilisers (especially nitrogenous ones) could reduce the species diversity of the sward. Since the hardback publication of Harvey’s book, an even earlier example of an ecological experiment with grass has been unearthed. A detailed description of the Hortus Gramineus at Woburn Abbey was published in 1816. It consisted of almost 250 experimental plots, each planted with different combinations of grasses and other pasture plants. Although it, too, fell short of modern standards of experimental design and analysis, the results from the Woburn plots were nevertheless indicative of the complexity of the links between productivity and diversity. They provided Charles Darwin with one of many pointers to the entwined relationship between the evolutionary diversity of form and the ecological context in which it is embedded, a topic that continues to preoccupy ecologists.
Experiments in ecology are among the most challenging of any science, for a number of reasons. A good experiment is one that consistently yields the same result given the same conditions, regardless of who is performing it. It is also one that provides a result that reflects the properties of the real world, yet the scientific tendency is always to reduce the number of variable parameters to enable the experimenter to nail the answer. In the natural world, plants and animals live not only in a fluctuating physical environment, with varying temperature, rainfall, light and bedrock, but also in a complex web of biological variables – the identity of their neighbours, the relative abundance of prey or predators, the presence or absence of parasites and pathogens, all of which are themselves subject to the vagaries of demography and genetics. Add to this the length of time and the spatial scale that some experiments would require (how, for example, would you assess, in a replicable manner, the effects of varying the number of tree species in a forest on the forest’s productivity?) and the enterprise becomes daunting. To be fair, Harvey’s concern is not so much with ecology as with agriculture, but he does less than justice to ecology by dwelling at some length on a functional categorisation of herbaceous plants proposed three decades ago, when he might have moved on to subsequent and contemporary disputes and developments. There are, though, reminders throughout his book of the diversity of grasses, and of the ecological properties and preferences of different species, alone or in combination with each other and other herbaceous plants. Cocksfoot and tall fescue are the productive pasture grasses, in the company of deep-rooting herbs such as chicory and legumes like clover. Common bent and sheep’s fescue are the dominant species of sheep-grazed lower mountain slopes and heathlands. In the species-rich chalk downs of Southern England, sheep’s fescue and red fescue are joined by the oat grasses and a host of other herbaceous species tolerant of being grazed to within a few millimetres of the soil surface. Perennial ryegrass, Lolium perenne, is the workhorse of the grass family, prized by groundsmen for its resilience to trampling, skidding and tearing, and by farmers for its productivity and all-round toughness. Harvey calls it the Attila of the grass family, so favoured by farmers that it now dominates swathes of land once home to the species-rich pastures and meadows that occupy ever-dwindling pockets of the British countryside. The loss of species-rich grassland to agricultural improvement has become one of the most urgent concerns of conservationists: some counties have lost more than half of their hay meadows and flood-plain meadows in the past twenty years.
The decline of the natural fertility of pasture is, if anything, the dominant theme of The Forgiveness of Nature. In his accounts of medieval sheep farming, Welsh hill farming, 16th-century water meadows, enclosure and its miserable consequences, the introduction of the red clover rotation, the draining of the fens, and the 19th-century decline of British pasture with the arrival of cheap meat from America and the colonies, Harvey presents pasture and its uses and abuses as having been an engine of change and development in British society and its economy for over six hundred years. It’s a convincing and well told story. It is remarkable how long ago the effects of overexploitation of the land began to make themselves felt. The relatively sparse human populations of five hundred years ago placed sufficient demands on the land to cause chronic reduction in fertility, and led farmers to begin their erratic attempt, which continues to this day, to maintain and improve yields through intervention and intensification.
Harvey finds the origins of intensification in a breathtakingly reductionist theory advanced in 1840 by Baron Justus von Liebig. The quantity of the major plant nutrients – nitrogen (N), phosphorus (P) and potassium (K) – in a harvested plant could be measured in its ash, after the carbon, oxygen and hydrogen had been burned off. From there it would be easy to calculate the amount of each nutrient removed from each acre of soil at harvest, and to replenish with inorganic salts containing N, P and K in appropriate measure. The application of von Liebig’s ruthless and apparently unarguable logic has transformed agricultural practice around the globe, with wonderful or disastrous consequences, depending on your point of view. On the one hand, an annual application of NPK obviates the need for crop rotation or muckspreading, maintains high yields – often on previously marginal land – and has sustained a growing human population. On the other hand, it progressively reduces the abundance and diversity of soil organisms and plants and erodes soil’s natural fertility bank to what can be an irreversibly low level. Despite the eagerness with which von Liebig’s chemical approach to fertility was adopted by Victorian farmers, especially rich ones, there were doubters from the start; Royal Commissions and correspondence in the Times debated the relative merits of chemical and organic approaches to agriculture. But the champions of chemical fertilisers gradually achieved dominance. Harvey argues that this might not have happened had Darwin published his last book, on the biology of worms, before von Liebig produced his monograph. Darwin’s book, which appeared in 1880, highlighted the crucial role of earthworms in mixing the organic and mineral components of the soil. Had the order of publication been reversed, however, I suspect the result would have been much the same: technological innovation that increases profits and reduces labour costs is always a winner, even when the longer-term hazards are well recognised.
Harvey’s final chapters chronicle the (largely rearguard) arguments and activities of the organic lobby over the past 150 years, and he ends by exhorting a return to the grass ley and a decisive switch to organically produced food. In this he echoes the views of George Stapledon, the first director of the Welsh Plant Breeding Station in Aberystwyth (now the Institute of Grassland and Environmental Research). Stapledon recognised the links between grassland and rural prosperity. In the 1930s, he had managed to improve dramatically the productivity of impoverished hill pastures in Wales, and during World War Two he had advocated a switch to the ley system, which did indeed enjoy a brief renaissance in the postwar years. His vision was of a Britain of many small farms in a landscape that provided not only for the livelihood of farmers but also for the recreational needs of city dwellers. Stapledon didn’t appear to anticipate, however, that agricultural subsidies would favour the larger, more profitable farms that had begun to absorb smaller holdings. This, in turn, favoured the hegemony of intensive inorganic chemical farming over the grass ley rotation. The last three decades of the 20th century took the British landscape along a very different path from Stapledon’s ideal. Decreasing use of grass, whether as ley or fodder, has locked farmers into increasing reliance on fertilisers and pesticides, with damaging consequences for humus, soil fauna and farmland insects and birds. Twenty years ago, a summer drive in the country would yield a windscreen-full of assorted dead insects; now the windscreen wash is needed only to wipe away the dirt thrown up by other vehicles. It is not just wildlife that has suffered. The disaster of BSE was caused, it now seems, by feeding animal protein to cattle in an attempt to boost or at least maintain milk yields in the absence of grass-based fodder. Such disasters were feared by Stapledon, though their exact nature could not have been anticipated. Harvey highlights yet another potential disaster: the transformation of the soil through inorganic fertilisation has led to a gradual loss of humus and organic matter on such a scale that it has become a significant contributor to global climate change. By a logic similar to von Liebig’s, Harvey reckons that a return to the grass ley rotation around the globe would be enough to absorb all the carbon dioxide emitted by internal combustion engines. But just as von Liebig neglected (or rather, was unaware of) the complexity of soil ecology in his reduction of agriculture to chemistry, Harvey ignores the short-termism of his solution, as well as the complexities of the global carbon cycle. By any standards of environmental sustainability, it’s hard to gainsay Harvey’s general view that the restoration of natural soil fertility must be beneficial, but halting climate change in the long term (not that long, perhaps: in the worst scenarios, there are just a few decades left) will also need, on current evidence, a massive conversion from fossil fuel to renewable energy sources in order to achieve a reduction in carbon emissions to pre-20th-century levels. De-intensification of agriculture could play a part in this process, but might not buy much more than a little illusory time. ‘The forgiveness of nature’ is a phrase borrowed from an article that appeared in the Kansas Magazine 130 years ago, extolling the capacity of grass to cover the scars inflicted on the landscape by people. The capacity for forgiveness might by now be wearing rather thin.