. in 1919.
Jethro Tull's
seed drill ( 1701) was a mechanical seed spacing and depth placing device that increased crop yields and saved seed. It was an important factor in the
British Agricultural Revolution. Since the beginning of agriculture threshing was done by hand with a
flail, requiring a great deal of labour. The
threshing machine, which was invented in 1794 but not widely used for several more decades, simplified the operation and allowed the use of animal power. Before the invention of the
grain cradle (ca. 1790) an able bodied labourer could reap about one quarter acre of wheat in a day using a sickle. It was estimated that each of Cyrus McCormick's horse-pulled
reapers (ca. 1830s) freed up five men for military service in the US Civil War. Later innovations included raking and
binding machines. By 1890 two men and two horses could cut, rake and bind 20 acres of wheat per day. In the 1880s the reaper and threshing machine were combined into the
combine harvester. These machines required large teams of horses or mules to pull. Steam power was applied to threshing machines in the late 19th century. There were steam engines that moved around on wheels under their own power for supplying temporary power to stationary threshing machines. These were called
road engines, and Henry Ford seeing one as a boy was inspired to build an automobile. With internal combustion came the first modern tractors in the early 1900s, becoming more popular after the
Fordson tractor (ca. 1917). At first reapers and combine harvesters were pulled by teams of horses or tractors, but in the 1930s self powered combines were developed. Advertising for motorised equipment in farm journals during this era did its best to compete against horse-drawn methods with economic arguments, extolling common themes such as that a tractor "eats only when it works", that one tractor could replace many horses, and that mechanisation could allow one man to get more work done per day than he ever had before. The horse population in the US began to decline in the 1920s after the conversion of agriculture and transportation to internal combustion. Peak tractor sales in the US were around 1950. In addition to saving labour, this freed up much land previously used for supporting draft animals. The greatest period of growth in agricultural productivity in the US was from the 1940s to the 1970s, during which time agriculture was benefiting from internal combustion powered tractors and
combine harvesters, chemical fertilisers and the green revolution. Although US farmers of corn, wheat, soy, and other commodity crops had replaced most of their workers with harvesting machines and combines by the 1950s enabling them to efficiently cut and gather grains, growers of produce continued to rely on human pickers to avoid the bruising of the product in order to maintain the blemish-free appearance demanded by customers. The continuous supply of undocumented workers from Latin America that harvest the crops for low wages further suppressed the need for mechanisation. As the number of undocumented workers has continued to decline since reaching its peak in 2007 due to increased border patrols and an improving Mexican economy, the industry is increasing the use of mechanisation. Extensive adoption started in the United States of America, where tractors replaced about 24 million draught animals between 1910 and 1960 and became the main source of farm power. United Kingdom first started using tractors in the 1930s, but agricultural transformation in Japan and some European countries (Denmark, France, Germany, Spain and former Yugoslavia) did not take place until about 1955. Thereafter, the adoption of motorised mechanization took place very quickly, completely superseding animal traction. Using tractors as farm power enabled, and even triggered, innovations in other agricultural machinery and equipment that greatly eased the toil associated with agriculture and allowed farmers to carry out tasks more quickly. At a later stage, motorised machinery also increased in many Asian and Latin American countries. A study in 11 countries proves this low level of mechanisation in the region, finding that only 18 per cent of the sampled households have access to tractor-powered appliances. The remaining ones make use of either simple hand-held tools (48 per cent) or animal-powered equipment (33 per cent). If rising wages and labour scarcities drive the adoption of automation then it is not likely to create unemployment. Automation can also stimulate agricultural employment. For example, it can enable farms to increase their production following growing food demand. Agricultural automation is part of the structural transformation of societies through which increased agricultural labour productivity gradually releases agricultural workers, giving them the opportunity to take new jobs in other sectors, including industry and services. On the other hand, automation that is forcibly promoted, such as through government subsidies, could cause rising unemployment and falling or stagnant wages. The
Food and Agriculture Organization of the United Nations (FAO) advises against governments implementing distortive subsidies for automation because doing so risks increasing unemployment. FAO also advises against restricting automation on the assumption that this will save jobs and incomes, because it risks making agriculture less competitive and productive. Instead, the recommendation is to concentrate on creating an enabling environment to adopt automation – particularly by small-scale agricultural producers, women and youth – while making social protection available to least skilled workers, who are more likely to lose their jobs during the transition. ==Applications==