FEEDING THE TEN BILLION
PLANTS AND POPULATION GROWTH
L.T. EVANS
CAMBRIDGE UNIVERSITY PRESS 1998
PART V
Chapter 5: Towards the First Billion (1500-1825) (Cont)
5.5 The Norfolk agricultural ‘revolution’
The Norfolk agricultural revolution exemplifies the complex inter-relations between population growth, industrialization and agricultural development. Its roots in England go back to the beginnings of enclosure of the ‘commons’ in the 16th century, well before Sir Richard Weston returned from the Netherlands. Its full flowering was reached with Coke of Norfolk (1754-1842) early in the 19th century.
- Between 1700 and 1830, the English population grew from 5.1 million to 13.3 million and the number of horses trebled, yet both horses and people were fed and, for a period, England was also ‘the granary of Europe’.
- This great expansion of agricultural production was achieved along with a fall in the proportion of the population engaged in agriculture from 55% in 1700 to only 25% in 1830, thereby freeing labour for the new industries and creating a strong demand for cereals in the towns.
Throughout this whole period the area of arable land continued to increase, as did the frequency of cropping, but the key to the advances in agricultural production was the progressive enclosure of the commons, begun in 16th century Shropshire to turn arable into grassland but promoted under King George III for the opposite purpose, in response to relatively higher cereal prices.
- In 1771, Young had referred to ‘the Norfolk system’ as having seven points: first, enclosures without assistance from Parliament; second, use of marl and clay; third, proper rotation of crops; forth, culture of turnips, hand hoed; fifth, culture of clover and ray (rye)-grass; sixth, long leases; and seventh, large farms.
- This was the period in which the Norfolk four-course rotation became widely established: turnips in the first year, as fodder for cattle or ‘folded’ for sheep; thus manured and well cultivated, the soil was then suited to a crop of wheat or barley, with the straw later used for farmyard manure; this was followed by a clover ley to restore soil nitrogen and provide grazing; finally another crop of barley or wheat was commonly taken.
Note that in his 1771 list of seven points, given above, Arthur Young specified ‘turnips, hand-hoed’. This was almost 40 years after Jethro Tull had published his Horse-Hoeing Husbandry with his persuasive argument for sowing crops in drilled rows so that seed was saved and horse-drawn ‘hoes’ could replace the armies of ‘sarclers’ needed to keep the weeds at bay. The advantages of drilled rows, including economy in the use of seed for sowing, had been recognized by the Chinese in the 6th century AD, and usable drills had been designed by them and by others before Tull. Yet it was not until the 1790s that his labour-saving system of cultivation came into widespread use, leading to a second phase of improvement. Although many of the individual components of the English agricultural revolution had a long history, it was the synergistic interactions between them in the Norfolk system that made it such an effective agent of improvement.
The tragedy of the commons, to use Garret Hardin’s phrase, was unavoidable. As Lord Ernle put it: ‘The divorce of the peasantry from the soil, and the extinction of commoners, open-field farmers, and eventually of small freeholders, were the heavy price which the nation ultimately paid for the supply of bread and meat to its manufacturing population.’ Along with these losses the farmer become less of a husbandman and more of an entrepreneur.
5.6 Malthus and his Essay on population
Thomas Robert Malltiss (changed to Malthus in 1792) was born in 1766, first published his Essay on the Principle of Population in 1798, and died in 1834. His life therefore coincided with the ‘Norfolk Revolution’ in agriculture, and with the shift from agriculture as the dominant economic activity in England to its being overtaken by industry and urbanization.
The 1790s were a particularly turbulent decade in England with rapid population growth and industrial expansion, a series of poor harvest from 1794 to 1800, high food prices, and widespread concern and several government enquiries about the vulnerability of the nation’s food supply. Popular unrest reached a peak in 1795. This was the background against which Robert Malthus wrote his first Essay. It was an opportunity for a general treatment and he seized it.
The young Malthus began his Essay boldly with his famous statement on the relation between rates of increase of population and of food supply. With Benjamin Franklin’s observation on the prolificacy of plants and animals in mind, and after considering the demographic evidence, particularly from America, he concludes: ‘It may safely be pronounced therefore that population when unchecked goes on doubling itself every 25 years, or increases in a geometrical ratio.’ As for the food supply he thought a doubling in Britain in the first 25 years would be ‘a greater increase than could with reason be expected’, and likewise ‘every 25 years by a quantity equal to what it at present produces: the most enthusiastic speculator cannot suppose a greater increase than this’. Therefore ‘the means of subsistence, under circumstances the most favorable to human industry, could not possibly be made to increase faster than in an arithmetical ration.’ Thus, the further increase in world population, which he correctly estimated to be about one billion at the time, ‘can only be kept down to the level of the means of subsistence by the constant operation of the strong law of necessity acting as a check upon the greater power.’
This elementary but emotively powerful mathematical contrast, delivered in trenchant prose with polemical purpose, had an immediate political impact. Yet Malthus must have known that he was on shaky ground for increases in the means of subsistence, as suggested by his more cautious wording in his Summary View of the Principle of Population. Malthus was writing his Essay at a time when the English arable was being extended and yields were rising rapidly under the impact of the Norfolk rotation. Comprehensive but unpublished surveys of the yield of wheat in England from 1809 to 1859 suggest that it may indeed have doubled within the 25 period between 1835 and 1859. When combined with the increase in arable area, this would have increased production by more that Malthus’ most enthusiastic speculator could suppose.
In 1798 there was no international or even national data base by which to estimate increases in food production but there was also no strong reason why Malthus should have summarily excluded the possibility of a geometric increase in food supply. It is true that Adam Smith and David Ricardo also rejected the possibility of geometric growth in the economy, because of diminishing returns on a limited supply of arable land, but I suspect the young Malthus also recognized the dialectical force of the geometric/arithmetic contrast. It has been said of Malthus that no other social scientist has been both attacked and defended with so little regard for what he actually wrote. Part of the problem has been the extensive changes he made in the course of the six editions of his Essay as he acquired more data and widened his experience.
5.7 The Irish potato famine
The potato famine of 1845/46 looms over Irish history but also over demography through having been viewed as a timely example and justification of the concerns expressed by Malthus. Indeed Malthus and others had forewarned of the likelihood of a food supply crisis in Ireland at various times during the 50 years before it actually occurred. The main reasons for their concern were the rapid increase in population – said by Malthus to be the fastest outside America – and the almost total dependence of many of the poorest people on one food crop.
Given the overwhelming importance of the potato in Ireland by the end of the 18th century, it is surprising how little is known about its early adoption and spread there. But it was well adapted to the more humid areas and it complemented the cereals in the sense that poor years for cereals tended to be good years for the potato and vice versa. In a nutritional sense the potato also complemented the milk products which were a significant component of Irish diets. Even Arthur Young had to admit that the potato must be a good food. Referring to the Irish country folk he wrote ‘When I see (their) well formed bodies, their men athletic and their women beautiful, I know not how to believe them subsisting on an unwholesome food.
Between Young’s visits in the 1770s and the onset of the famine, the population of Ireland doubled to reach 8 million, for which the potato is often held to blame. The relative yields of potato and cereal crops at the time were such that throughout northern Europe, 3-4 times more people could be fed by an acre of potatoes than by an acre of wheat. Today, by contrast, average wheat yields in Ireland are over 40% higher than those of potatoes in terms of edible dry matter. Crop yields in late 18th century Ireland were as high as those in England and much higher than those in France. Quite small holdings could provide all the food required by a family, but little else. Because most landowners did not require the labour of their tenants, rents were paid by the sale of cereals or, in earlier years, of household crafts such a linen.
- On the eve of the famine potatoes accounted for rather less than a quarter of the value of overall Irish agricultural output compared with almost 40% for other crops and 22% for cattle and dairy products.
- Given the extent of agricultural exports from Ireland, even a halving of the potato crop in 1845 and 1846 need not have created a famine in which 800,000 additional deaths occurred as well as accelerated emigration.
- The excess mortality was far higher than in more industrialized countries such as Belgium, where the potato crop also failed.
- The problem was that although potatoes made up less than a quarter of Ireland’s agricultural production, they were nevertheless the predominant food of more than 3 million people as well as a major element in the diet of the remainder, and if their landlords demanded their cereals for rent, starvation was inevitable.
- That Ireland would be undone by a failure of the potato crop had been anticipated by some but that the cause was fungal parasite was neither foreseen nor believed. After all, Louis Pasteur’s germ theory of disease was still 25 years away in the future.
- In August of 1845, after a period of cool, wet weather, Belgian potato fields were reported to be devastated by a ‘murrain’ far more destructive than scab or curl.
The rest is history, nearly all of it with emphasis on the causes – demographic, geographic, economic, political or social – of the famine. Yet the immediate cause of the disaster, the murrain, had several major effects on subsequent agricultural history. For one thing, with the repeal of the Corn Laws in 1846, it turned the United Kingdom away from a policy of self-sufficiency and protection of domestic agriculture towards free trade and inter-dependence. And it led to the first recognition that ‘murrains’ and diseases of crops could be caused by micro-organisms and might therefore be controllable.
So what has been called the greatest gift of the New World to the Old was eventually joined by its greatest scourge to give rise not only to ‘the last great natural disaster in Europe’ as Mokry refers to it, but also to the science of plant protection.
Chapter 6: The Second Billion (1825-1927)