It takes a long time, up to several decades, before the benefits of organic farming take full effect on land that was previously cultivated conventionally, a new study from Lund University suggests. After thirty years, the plant species richness around the cultivated crop had doubled on organic farms compared to conventional farms. It takes a long time, up to several decades, before the benefits of organic farming take full effect on land that was previously cultivated conventionally, a new study from Lund University suggests. After thirty years, the plant species richness around the cultivated crop had doubled on organic farms compared to conventional farms. Ecology Agriculture Phys.org – latest science and technology news stories