Inadequate farm crop diversity

Monoculture of crops
Single crop farming
Insufficient polyculture
Monocultures are highly unstable and unsustainable systems that spread not because they produce more food but because they produce more control.
The mindset that assumes that monocultures are essential for solving problems of scarcity underlies programmes such as World Bank-financed schemes that replace diverse natural forests with pine or eucalyptus plantations, and turn diversified farms into monocultures of "miracle" wheat or rice.
Mechanized agriculture has made broadscale farming of single crops very efficient. The advantages for disease and pest management afforded by small-scale intermixed crops have been offset by chemical pesticides.
(D) Detailed problems