<P> The mechanisation and rationalisation of agriculture was another important factor . Robert Bakewell and Thomas Coke introduced selective breeding, and initiated a process of inbreeding to maximise desirable traits from the mid 18th century, such as the New Leicester sheep . Machines were invented to improve the efficiency of various agricultural operation, such as Jethro Tull's seed drill of 1701 that mechanised seeding at the correct depth and spacing and Andrew Meikle's threshing machine of 1784 . Ploughs were steadily improved, from Joseph Foljambe's Rotherham iron plough in 1730 to James Small's improved "Scots Plough" metal in 1763 . In 1789 Ransomes, Sims & Jefferies was producing 86 plough models for different soils . Powered farm machinery began with Richard Trevithick's stationary steam engine, used to drive a threshing machine, in 1812 . Mechanisation spread to other farm uses through the 19th century . The first petrol - driven tractor was built in America by John Froelich in 1892 . </P> <P> The scientific investigation of fertilization began at the Rothamsted Experimental Station in 1843 by John Bennet Lawes . He investigated the impact of inorganic and organic fertilizers on crop yield and founded one of the first artificial fertilizer manufacturing factories in 1842 . Fertilizer, in the shape of sodium nitrate deposits in Chile, was imported to Britain by John Thomas North as well as guano (birds droppings). The first commercial process for fertilizer production was the obtaining of phosphate from the dissolution of coprolites in sulphuric acid . </P> <P> Dan Albone constructed the first commercially successful gasoline - powered general purpose tractor in 1901, and the 1923 International Harvester Farmall tractor marked a major point in the replacement of draft animals (particularly horses) with machines . Since that time, self - propelled mechanical harvesters (combines), planters, transplanters and other equipment have been developed, further revolutionizing agriculture . These inventions allowed farming tasks to be done with a speed and on a scale previously impossible, leading modern farms to output much greater volumes of high - quality produce per land unit . </P> <P> The Haber - Bosch method for synthesizing ammonium nitrate represented a major breakthrough and allowed crop yields to overcome previous constraints . It was first patented by German chemist Fritz Haber . In 1910 Carl Bosch, while working for German chemical company BASF, successfully commercialized the process and secured further patents . In the years after World War II, the use of synthetic fertilizer increased rapidly, in sync with the increasing world population . </P>

There were at least three independent centers of domestication in the new world