From the 16th century there were many changes in traditional farming practices in Briain. These changes intensified during the 18th century. This was partly due to the need to provide food for the rapidly increasing population. Food production increased partly because of new farming techniques, such as crop rotation. Woodland was also cleared to create new farmland, and upland areas, previously used for sheep farming began to be used to grow crops. New types of crops were bred, including new fodder crops, such as turnips, which were used to feed animals. These new fodder crops meant that land previously used to graze animals was used to grow food. New ways of improving soil quality were also discovered, such as adding lime to fields, and creating better manure. Many new machines, such as seed drills and threshing machines, were invented to help speed up work and make it more efficient. As well as changes to crops, there were also changes in animal farming, particularly as new breeds were developed and better feeds and fodder crops introduced. The increased efficiency in farming meant that many farmers became very wealthy. They often used their new wealth to build new farm buildings, barns and byres, and model farms are common in the north-east.