How to do? By using abandoned farms

How? By making use of abandoned farms.As the market for food is globalized,infertile land becomes uncompetitive.Farmers in barren places can't compete with people growing crops on better land elsewhere.As a result, farming has started to retreat from many regions,
and trees have started to return.One estimate claims that two-thirds of land in the US that was once forested but was cleared for farming
has become forested again.Another estimate suggests that by 2030,an area in Europe the size of Poland will be vaccated by farmers.