The Conditions of Agricultural Growth

The Economics of Agrarian Change Under Population Pressure

Ester Boserup

• Publisher: Routledge
• Year: 2014
• ISBN:
  9781134162215
• Edition: 1
• Topic: Economics
• Subtopic: Economic Theory
• Index: Economics

When it first appeared in 1965, The Conditions of Agricultural Growth heralded a breakthrough in the theory of agricultural development. Whereas 'development' had previously been seen as the transformation of traditional communities by the introduction (or imposition) of new technologies, Ester Boserup argued that changes and improvements occur from within agricultural communities, and that improvements are governed not only by outside interference, but by those communities themselves.

Using extensive analyses of the costs and productivity of the main systems of traditional agriculture, Ester Boserup concludes that technical, economic and social changes are unlikely to take place unless the community concerned is exposed to the pressure of population growth. In sharp contrast to widely accepted ideas, she shows how population growth may be the main stimulus to agrarian change. In developing this theme, the author identifies successive stages of agriculture, characterized by differences in techniques of cultivation and in social structure and show how they can be explained by differences in population density. This book is of relevance not only to economists, but also to historians interested in the way present changes in agrarian communities parallel those of the past.

CHAPTER 1
THE DYNAMICS OF LAND UTILIZATION

The intensity of land utilization varies widely throughout the world. In large regions of Africa and Latin America, and in some parts of Asia, the system of land use is very extensive, with one to two years’ cultivation followed by a fallow period of at least twenty years. The other extreme is found in Egypt and parts of the Far East, where most of the land which bears crops does so at least twice every year. Between these extremes are intermediate intensities of land use, and it is often found that one part of a country is under highly intensive cultivation, another part under annual cropping and a third part under various more or less extensive fallow systems.

Any classification of the systems of land use with respect to the degree of intensity is necessarily arbitrary to some extent. In order to simplify the analysis in the following chapters I have chosen a grouping with only five types of land use. These are as follows, in order of increasing intensity:

(1) Forest-fallow cultivation. Under this system of land use, plots of land are cleared in the forests each year and sown or planted for a year or two, after which the land is left fallow for a number of years sufficient for the forest to regain the land. This means that the period of fallow must be at least some twenty to twenty-five years. The type of forest which grows up in territories which are regularly used for forest fallow is known as secondary forest, as distinguished from the primary or virgin forest, which was never cultivated or was left uncultivated for a century or more.

(2) Bush-fallow cultivation. Under this system the fallow is much shorter, usually somewhere between six and ten years. No true forest can grow up in so short a period, but the land left fallow is gradually covered with bush and sometimes also with small trees. The periods of uninterrupted cultivation under bush-fallow systems varies considerably. It may be as short as one to two years (similar to conditions under forest fallow) and it may be as long as the fallow period, i.e. six to eight years. Many authors do not distinguish between forest and bush fallow systems, but group them together under the label of long-fallow cultivation, or shifting cultivation.

(3) Short-fallow cultivation. The fallow lasts one year or a couple of years only. In such a short fallow period, nothing but wild grasses can invade the fallow, before the cultivator returns to the same plot or field. The system could therefore also be described as grass-fallow cultivation, but the term short fallow is to be preferred since under certain conditions land may lay fallow for very long periods without being invaded by anything but wild grasses. It is important, therefore, to distinguish between grass areas used in long-fallow systems and grass areas used in short-fallow rotations.

(4) Annual cropping. This is usually not considered a fallow system, but may be classified as such, because the land is left uncultivated, usually for several months, between the harvest of one crop and the planting of the next. This group is meant to include systems of annual rotation, in which one or more of the successive crops are sown grass or other produced fodder.

(5) Multi-cropping. This is the most intensive system of land use, since the same plot bears two or more successive crops every year. The planting of a new crop must therefore take place shortly after the harvesting of the preceding one and the fallow period is short or even negligible.¹

Under the pressure of increasing population, there has been a shift in recent decades from more extensive to more intensive systems of land use in virtually every part of the underdeveloped regions. In some parts of the world, cultivators under the forest-fallow system have been unable to find sufficient secondary forest. They have then had to re-cultivate areas not yet bearing fully grown forest. In this way, the forest has receded and been replaced by bush. Again, in regions of bush fallow the cultivators have changed to short-fallow systems or annual cropping and many short-fallow cultivators have changed to systems of annual cropping with or without irrigation. In the densely populated regions of the Far East, the growth of population during this century has caused a rapid spread of multi-cropping.

THE HISTORICAL SEQUENCE

Shortening of fallow is not a feature which is characteristic of the twentieth century only. Historical investigations have revealed that there was a gradual shortening of fallow in western Europe during and after the Middle Ages ending in the change to annual cropping in the second half of the eighteenth century. But the evidence of a process of gradual shortening of fallow in Europe is not limited to the period for which we have written sources. Archeological research has given indication of the existence of a system of agriculture based on forest fallow in the neolithic period in Europe.¹ By combining the results of archeological and historical research we get the picture of a successive change in Europe from neolithic forest fallow to systems of shifting cultivation on bush and grass land followed first by short-fallow systems and in recent centuries by annual cropping.

Our knowledge of agrarian history is much more fragmentary for other parts of the world than for Europe. However, pollen studies and other archeological research point to the world-wide use in the neolithic period of a system of cultivation of forest plots, probably very much resembling the type of cultivation that is now found in many primitive communities. This contrasts with an earlier theory, according to which intensive cultivation in river valleys would have preceded the cultivation of forest land. The older theory seems to have been based upon the view that forest land was too difficult to cope with for very primitive peoples. This, however, ignores the fact that not felling but fire was the method of clearing forest land, and it seems that experts in the field now tend to think that river shore cultivation may have been taken up by descendants of tribes who had lost the forest land they had cultivated owing to desiccation or exhaustion and ended by crowding along the rivers. The Sahara and other deserts close to regions of ancient river cultivation are being searched for evidence to support or refute these theories.²

The historical sequence of the different types of cultivation is difficult to establish, because all the major agricultural systems used today—apart from modern chemical and mechanized agriculture—are several thousand years old. But it does not matter much for a discussion of the general process of development of agriculture, if some tribes may have discovered that the shores of a particular river could be sown and harvested annually without land preparation before or after forest-fallow cultivation had been used in the neighbourhood. Even if we cannot be sure that systems of extensive land use have preceded the intensive ones in every part of the world, there seems to be little reason to doubt that the typical sequence of development of agriculture has been a gradual change—more rapid in some regions than in others—from extensive to intensive types of land use. The classification of types of land use suggested above is therefore more than just an attempt to identify and classify various types of agriculture existing today and in the past. It is supposed, at the same time, broadly to describe the main stages of the actual evolution of primitive agriculture, during prehistoric times and in the more recent past.

LAND USE IN THE TROPICS

In previous centuries, the European settlers and colonial officers in regions where long-fallow cultivation dominates were overlooking that the apparently unused forest and bush lands served as fallow for the native population. Large amounts of such land were expropriated for the use of European settlers or plantation companies or they were declared restricted forests where natives were not allowed to clear plots for cultivation. It was assumed that no damage was inflicted on the native population, as long as they were left in the possession of the land they had under actual cultivation and were given, in addition, a certain amount of uncultivated land. The latter was meant as an area for the collection of fuel and other materials and for the expansion of cultivation in case the population should increase.

This kind of land policy ignored the fact that large parts of the territories from which the natives were thus excluded had formerly served as fallow in long-fallow rotations. The expropriation of such land would necessarily compel the cultivators to shorten the fallow period and sometimes the soil became exhausted by excessive cultivation. The exhaustion of the soil in the native reserves and the complaints of the natives eventually opened the eyes of many Europeans to the existence of the systems of long-fallow cultivation and these have since been the subject of studies by many economists, agronomists and social anthropologists.

Most of the regions where long-fallow cultivation dominates today are found in the tropics, and this can largely explain why the long-fallow systems were considered to represent an adaptation to the special conditions of soil and climate in the tropical zone. We have an example of this line of thought in Pierre Gourou’s widely read book The Tropical World.¹ He assumes in fact that the soil in most of the tropical zone cannot be used for other systems of cultivation than long fallow. In his view, only volcanic soil or soil regularly receiving top soil from other regions—by flooding or in other ways—would be able to support more intensive cultivation. This pessimism regarding the fertility of tropical land goes hand in hand with a Malthusian interpretation of the demographic situation in the tropics. Professor Gourou supposes that most of the tropics is sparsely populated because the land is unable to support cultivation for more than one year out of twenty and therefore unable to support a numerous population. Gourou’s conclusion is that the number of people in the tropics has grown to what the territory can carry, and that additional population must largely be accommodated by means of industrialization and reliance on foreign trade.

The belief that there is little scope for intensive land use in the tropics was not left uncontested. It was discussed at the Inter-African Soil Conference in Leopoldville in 1955.¹ Both at this conference and in recent contributions by many experts and even by Gourou himself a considerably more optimistic view is taken concerning the scope for spreading methods of intensive land utilization in Africa and other tropical regions.² It is stressed that the land used for intensive cultivation, for instance in parts of Nigeria, is of the same type as that used in long-fallow rotations in Nigeria and elsewhere with similar climatic conditions. Fertility may be the result of the use of intensive methods of land utilization and not vice versa.

THE CHANGING LANDSCAPE

The discovery of the earlier existence of long-fallow systems in regions which are now either deserted or cultivated in intensive systems of land use, has discredited the idea that the different fallow systems can be seen as adaptations to particular types of soil or climate. More and more authors seem to support a dynamic theory of land use, based on the recognition that there is a two-way connection between ‘natural conditions’ and fallow systems. It is now often suggested that in the neolithic period forests covered a much larger part of the land surface than now, and that the forest areas were reduced because they had been used in shifting cultivation and spoiled partly by too short fallow periods and partly by the use of fire for hunting purposes or because the fires used for land clearing got out of control. The forests would thus have been gradually replaced by bush and grass lands, in much the same way as that which can be observed nowadays in many regions of long-fallow cultivation and hunting.

When forests deteriorate, the grasses get their chance. In dense forest, grass cannot grow, but where the forest becomes thinner or is gradually replaced by bush wild grasses will spread. The grass-roots are not destroyed by fire, and land frequently exposed to fire therefore tends to become more and more grassy. The invasion of forest and bush by grass is most likely to happen when an increasing population of long-fallow cultivators cultivate the land with more and more frequent intervals. It has been observed, during the colonial period and after, that many areas previously under forest and bush gradually become savannah or other types of wild grass land, as a result of more or less frequent burning over or cultivation in relatively short rotations.¹ Many authors believe that a large share of the savannahs and other apparently natural grass lands owe their origin to similar changes in prehistoric times.

When forests are replaced by grass land natural fodder for cattle, horses and other herbivorous animals becomes available. Those who think that a large share of the grass lands of the world are man-made have therefore questioned the old theory, according to which the stage of nomadism would generally have preceded that of agriculture. According to that theory, nomadic tribes had first taken to clearing of land for cultivation when they had become too numerous to subsist by grazing of animals in natural grass lands. The sequence is now supposed to be the reverse: tribes which previously cultivated short-lived plots in forest and bush land have come to rely on the grazing of animals only after they have cultivated forest plots for a very long period ending in the transformation of the forest into grass land.

Some authors are of the opinion that the retreat of the forests served to make the climate more dry and thus facilitated the spread of deserts. Others think that the spread of barren land is the result primarily of erosion caused by over-cultivation and by over-grazing by the herds of nomadic tribes. There is recent evidence from many parts of the world of over-stocked grazings being destroyed by over-grazing and wind erosion or by fires laying the land bare before the rainy season so that the top soil is carried away by water erosion. Barren hills deprived of their earlier vegetation and top soil abound in most regions of ancient civilization, from China to the countries on both sides of the Mediterranean. It is not unlikely that over-grazing in the past is mainly responsible for the present state of these areas.

It is a moot question, how much importance over-cultivation and over-grazing had in changing climate and increasing desert areas.¹ Dudley Stamp concludes a UNESCO study of land use in arid regions with this cautious summary of recent opinions: The rapid development of ecological studies has thrown doubt on the primeval character of much tropical vegetation. Whether any of the savannahs and tropical grass lands with scattered trees can still be regarded as climax vegetation, uninfluenced by man, becomes increasingly doubtful and the same is true of the “natural” vegetation of semi-arid and arid lands. If deserts are spreading it remains uncertain how far the spread reflects climatic change and how far the conscious or unconscious work of man.’²

The neo-Malthusians have not missed the chance to interprete the dynamic theory of land use as a confirmation of Malthusian beliefs. Malthus thought that the increase of population to a level beyond the carrying capacity of the land must lead to the elimination of the surplus population either by direct starvation or by other positive checks which in his opinion could be traced back to the insufficiency of food supplies as the basic cause. The new version of Malthusian theory is based on the idea that the increase of population leads to the destruction of the land; and that people, in order to avoid starvation, move to other land which is then destroyed in its turn. The neo-Malthusians collect all the evidence on the misuse of land and paint a picture of the world as a place where g...