Soil tillage systems are predominantly concerned with the provision of an adequate seedbed to accommodate the subsequent crop seeding or planting operation and to provide an optimum environment for seed germination, plant establishment and vigorous crop growth. Traditional tillage systems involved breaking the soil crust with a human or animal powered implement or plow pushed or pulled through the soil. The history of agricultural growth and mechanization in some of today's industrial countries illustrates this generalization. In 1880, factor endowments differed widely among these countries, with Japan having only 0.65 hectares of land per male worker and the United States about forty times as much (see Binswanger and Ruttan 1978, tables 3-1 and 3-2).
Hay loaders became widely used in the United States after 1880 but did not spread in continental Europe until after World War 11, only to be quickly replaced by hay balers and other more sophisticated machines. Most of the animal-drawn harvesting machines derived their power from horses. Oxen could not be used successfully because sufficient power could be generated only at the higher speed of horses. For example, the growth of tractors in the United States was spread over a fifty-year period with occasional spurts, but once tractors became available, they took over primary tillage within a much shorter time. Their further growth involved shifting extra operations from horses to tractors. Today few farms in the Indian Punjab plow land with animals, thresh wheat by hand, or use Persian wheels. This is only fifteen years after tractors, threshers, and pumps became an important factor in Punjab farming.
By common consent, diesel oil (used to power the compression ignition engines, so dominant in agriculture) is a nonrenewable resource. Attempts to find or identify a diesel fuel substitute that could be used in conventional diesel engines have made some progress. In particular, the use of oils from renewable oilseeds has enjoyed some limited success in countries such as Austria, where generous tax remission is allowable on a fuel that is otherwise uneconomic.
Precision farming applications promise to conserve energy and reduce agricultural inputs but much remains to be done before these claims can be sustained and the technology commercialized at an affordable price to the farmer. Further exciting developments in farm machinery are under way with particular emphasis on communications and information technology applications.