Agricultural intensification can be technically defined as an increase in agricultural production per unit of inputs (which may be labour, land, time, fertilizer, seed, feed or cash). For practical purposes, intensification occurs when there is an increase in the total volume of agricultural production that results from a higher productivity of inputs, or agricultural production is maintained while certain inputs are decreased (such as by more effective delivery of smaller amounts of fertilizer, better targeting of plant or animal protection, and mixed or relay cropping on smaller fields). Intensification that takes the form of increased production is most critical when there is a need to expand the food supply, for example during periods of rapid population growth. Intensification that makes more efficient use of inputs may be more critical when environmental problems or social issues are involved. In either case, changes caused by intensification are to be understood conceptually in contrast to extensive adjustments, which involve increases or decreases in the amount of inputs used. Historically, the most common and effective extensive adjustment in agricultural production has been to increase or decrease the area of land planted.
For the purposes of this discussion, the contrast between intensification and extensive adjustment is intended to indicate the contrast between two broad strategies that human beings have had for affecting their food supply, rather than concepts applicable to economic or technical analysis of specific cases. The technical specifications and measurement of intensification or extensive adjustment in any given case are actually quite complex. Changes in the productivity of one input are likely to be accompanied by adjustments in the amount of other inputs. This complexity notwithstanding, there is little doubt that agricultural intensification has been a prerequisite to human civilization. The Neolithic technological revolution was built on collecting, concentrating, selecting and harvesting plant and animal species in an organized fashion, with the aim of having more products closer to hand and easier to convert into nutrition. The domestication of farm animals and the development of crops, in the context of ever more productive farming systems, enabled the human population to grow and towns and villages to develop, having governments, laws, trade and economies with specialized employment.
Applying fertilizer to a maize crop
As agricultural production became more efficient, so populations increased. Historians have argued whether higher populations drove technological development, or whether technological development made higher populations possible. Nevertheless, throughout this development, most societies were chronically malnourished, or prey to episodic famine. Relatively high transport costs meant that most societies relied on local production, except when water transport made imports possible. Classical Athens was largely fed from the Crimea, and Rome from Egypt and southern Spain. For more than 95 percent of the history of civilization, food has been scarce for nearly all people. This has meant low life expectancy, susceptibility to disease and little capacity to face wars, droughts, floods and other human and natural catastrophes. Food scarcity and social disorder brought about major migrations of people and caused wars and massive cultural disruption.
Conversely, when scarcity was relieved, major cultural advances were made. About 1 000 years ago, new varieties of rice were taken to southern China from the Champa Kingdom (now Viet Nam). These were not sensitive to photoperiod, and produced two crops a year instead of only one. When these varieties were grown, the intensive techniques that had developed slowly in China to increase productivity per unit of land, although requiring more labour, resulted in dramatic production gains. The subsequent rice surplus triggered changes across various sectors of Chinas economy, stimulating the construction of roads, canals, dams, ironworks, grain storage facilities and the production of weapons. For five centuries southern China experienced sustained economic growth and had favourable trade terms for silk, spices and technology with late Mediaeval and early Renaissance Europe.
The agricultural revolution in the early modern United Kingdom greatly increased agricultural productivity. It relied heavily on techniques based on horse power, soil-supporting crop rotations, land drainage and grazing systems, which were developed on the European continent in the very densely populated and often scarcity-ridden Low Countries (the present-day Benelux). When these innovations were applied to larger areas at lower human population densities, a significant surplus was produced, which made the Industrial Revolution possible. At the same time, the harnessing of energy sources became more efficient. The late eighteenth century saw improved water mills and windmills, the use of sea coals and the development of steam engines. Transport costs fell, making it economically viable, for example, to ship bones long distances for use in fertilizer. Internal combustion and hydropower later greatly increased returns to labour and the availability of products such as nitrogen fertilizers.
However, any technology exists within a social and political system. The way that this British agricultural surplus was generated, controlled and distributed under the restrictive Enclosure Acts forced most of the rural population off the land to serve as industrial labour. The result was high food insecurity and a structural form of urban poverty, where families no longer had access to land or to traditional rights such as commons and gleaning. Yet the growing surpluses allowed greater specialization, provided capital and cheap labour for industrialization in Europe and drove the long, violent European nineteenth century. They also resulted in much larger markets in food to supply a burgeoning population, which produced many more goods and services than at any time in previous history. However, the costs paid in human suffering by three or four generations of impoverished families were considerable.
An understanding of the ethical issues involved in intensification can take both a prospective and a retrospective outlook, and ethical standards for evaluating intensification can take either a broad outlook on the general trend of events or a specific focus on the particular responsibilities of key actors. There are three general ethical questions to be posed. First, it is possible to ask whether intensification in a given situation is good or bad, all things considered, without pointing to specific decisions or activities undertaken by particular people or organizations. Second, assuming that intensification is a good thing, how should the burdens and benefits of intensification be distributed? Third, who is responsible for seeing that intensification occurs and that it follows an ethically acceptable path? Beyond these questions, it will be critical to deploy the resources of the natural and social sciences to identify the impediments to intensification, as well as to identify factors that would make an ethically justified form of intensification become ethically problematic, but that task will not be attempted in the present paper. ·