In the Modern World
Agrarian societies transition into industrial societies when less than half of their population is directly engaged in agricultural production. Such societies started appearing because of the Commercial and Industrial Revolution which can be seen beginning in the Mediterranean city-states of 1000-1500 C.E.[7] As European societies developed during the Middle Ages, classical knowledge was reacquired from scattered sources, especially the Arabs, and a new series of maritime commercial societies developed again in Europe. The initial developments were centered in Northern Italy, in the city-states of Venice, Florence, Milan, and Genoa. By about 1500 a few of these city-states probably met the requirements of having half of their populations engaged in non-agricultural pursuits and became commercial societies. These small states were highly urbanized, imported much food, and were centers of trade and manufacture to a degree quite unlike typical agrarian societies.The culminating development, still in progress, was the development of industrial technology, the application of mechanical sources of energy to an ever increasing number of production problems. By about 1800, the agricultural population of Britain had sunk to about 1/3 of the total.[8] By mid-19th Century, all the countries of Western Europe, plus the United States of America had more than half their populations in non-farm occupations.[9] Even today, the Industrial Revolution is far from completely replacing agrarianism with industrialism. Only a minority of the world’s people today live in industrialized societies although most predominantly agrarian societies have a significant industrial sector.
The use of crop breeding, better management of soil nutrients, and improved weed control have greatly increased yields per unit area. At the same time, the use of mechanization has decreased labor input. The developing world generally produces lower yields, having less of the latest science, capital, and technology base. More people in the world are involved in agriculture as their primary economic activity than in any other, yet it only accounts for four percent of the world's GDP.[10] The rapid rise of mechanization in the 20th century, especially in the form of the tractor, reduced the necessity of humans performing the demanding tasks of sowing, harvesting, and threshing. With mechanization, these tasks could be performed with a speed and on a scale barely imaginable before. These advances have resulted in a substantial increase in the yield of agricultural techniques that have also translated into a decline in the percentage of populations in developed countries that are required to work in agriculture to feed the rest of the population.
Demographics
The main demographic consequences of agrarian technology were simply a continuation of the trend toward higher population densities and larger settlements. The latter is probably a more secure consequence of agrarian technology than the former. In principle livestock compete with humans for food and in some environments, advanced horticultural techniques can probably support more people per square kilometer than agrarian techniques.[11]Aside from average density, agrarian technology permitted urbanization of population to a greater extent than was possible under horticulture for two reasons. First, settlement sizes grew with agrarian technology because more productive farmers freed more people for urban specialty occupations. Second, land and maritime transportation improvements made it possible to supply great cities of 1,000,000, plus inhabitants such as Rome, Baghdad, and the Chinese capital cities. Rome, for example, could draw grain and other bulk raw materials from Sicily, North Africa, Egypt, and Southern France to sustain large populations, even by modern standards, using maritime transport on the Mediterranean.[12] It is productivity per unit of labor and transport efficiency improvements of agrarian technology that had the widest impact on the more peripheral culture core features of agrarian societies.
The populations of agrarian societies also have historically fluctuated substantially around the slowly rising trend line, due to famines, disease epidemics and political disruption. At least at the high points, population densities often seem to have exceeded the level at which everyone could be productively employed at current levels of technology.[13] Malthusian deterioration, under-employment and a decline in rural and lower-class urban standards of living, ensued.
