The British agricultural revolution is the name ascribed to a series of developments in agricultural practices in Britain over the course of the 18th century.

In England, the agricultural revolution followed directly from seven years of poor harvests, with farmers being particularly keen to capitalise on whatever they could reap. In Scotland the issues were somewhat different, and the enforced improvements resulted in a massive change to both the landscape and the population, culminating in the so-called Lowland Clearances.

At its most basic, the agricultural revolution consisted of four key changes in practice:

Inclosure

Prior to the 18th century, agriculture was much the same across Europe, and had been since before the Middle Ages. The system in operation was essentially post-feudal, with each villager subsistence farming their own strips of land in one of three large open fields.

From as early as the 12th century, some open fields in Britain were being inclosed into individually owned fields, with the process taking off rapidly in the 15th and 16th centuries as sheep farming grew more profitable. This led to villagers losing their land and grazing rights, and left many unemployed. In the 16th and 17th centuries, the practice of inclosure was denounced by the Church, and legislation was drawn up against it, but the developments in agriculture during the 18th century required large, enclosed fields in order to be workable. This led to a series of government acts, culminating finally in the General Inclosure Act of 1801.

While the villagers received compensation for their strips, it was minimal, and the loss of rights for the rural populous led to an increased dependency on the Poor law. Only a few found work in the (increasingly mechanised) inclosed farms. Most were forced to relocate to the cities and find work in the emerging factories, opening the way for the Industrial Revolution.

By the end of the 19th century the process of inclosure was largely complete.

Mechanization

Jethro Tull made the first advancements in agricultural technology with his seed drill (1701) - a mechanical seeder which distributed seeds efficiently across a plot of land.

Joseph Foljambe's Rotherham plough (1730), while not the first iron plough, was the first iron plough to have any commercial success, combining a number of technological innovations in its design, and being lighter than traditional ploughs. It remained in use in Britain until the development of the tractor.

Andrew Meikle's threshing machine of 1786 was the final straw for many farm labourers, and led to the 1830 agricultural rebellion of Captain Swing (a mythical character comparable to the Luddite's Ned Ludd).

Increasing mechanisation improved farming efficiency and reduced costs, not least by making many workers redundant.

Four Field Crop Rotation

During the Middle Ages, the open field system had employed a three year crop rotation, with a different crop in each of the three fields - eg. wheat and barley in two, with the third fallow.

Following the Black Death, depopulation made possible a shift in diet away from cereals towards meat and other animal products. Correspondingly, in many locales, legumes such as peas and beans, which made excellent livestock fodder, replaced barley as the spring crop in the three-field crop rotation. Also, some crop fields were retired towards permanent pasture. Over the following two centuries, the regular planting of legumes slowly increased the fertility of croplands, and when the pastures were brought back into crop production after their long fallow, their fertility was much greater than they had been in medieval times.

The Dutch discovered a still more effective four-field rotation system, introducing turnips and clover to replace the fallow year. Clover was both an ideal fodder crop, and it improved grain yields in the following year, simultaneously increasing cereal and livestock production. The-four field system was introduced to Britain from Holland in 1730 by Viscount Charles "Turnip" Townshend.

Selective Breeding

In England, Robert Bakewell and Thomas Coke introduced selective breeding (mating together two animals with particularly desirable characteristics), and inbreeding (to reduce genetic diversity in desirable animals) programs from the mid 18th century as methods for producing bigger and more profitable livestock.