Currently there is a trend of people erecting buildings, cutting down trees and hedges etc, then applying for planning retrospectively. Another trend is to buy a small piece of agricultural land and to use "loopholes" in the laws(this used to be called paragraph 79) to apply for "change of use" to  build houses or apply for "diversification" to build leisure facilities, which may have otherwise have been refused. Such landowners often do not have agricultural backgrounds and have no intentions of using land for agricultural purposes. As a result modern residential and other buildings are appearing on previously open countryside.