|Four-Field Crop Rotation|
|Research Points Needed|
|Building Needed||Tenanted Farms|
By planting four different crops in succession the quality of soil in a field can be markedly improved.
Simply: better soil means better harvests, and by grouping fields into fours, the crops are grown every year, just in different places. Farmers have long practiced crop rotation, leaving fields to lie fallow one year in every four to recover their fertility. This system works, but it means that a quarter of farmland is doing nothing every year. This reduces profits and food supply. Four-fields rotation adds an extra, useful crop to the series that actually improves the soil, clover or turnips are typical plantings.
Viscount Charles "Turnip" Townshend (1674-1738) brought this Dutch invention to England, earning his nickname for his devotion to the crop and his exceedingly predictable dinner conservations on the subject. Despite the boredom of his dinner guests, his improvements worked, and were part of a larger agricultural change that further enriched the landed classes. In England, with the Enclosure Acts that effectively stole the common grazing lands of the rural community, crop rotation made the wealthy even wealthier.
Four-Field Crop Rotation allows for the second tier of farm buildings to be built, dramatically increasing the speed at which regions develop new towns. The small cost of these farms is a small price to pay for such an advantage.