Subsistence farmers are threatened by the increasing use of genetically modified crops because these crops... deplete the soil faster than selectively bred crops, resulting in desertification and displacement

can easily be grown organically, resulting in a decrease in demand for nonorganic foods

reduce the nutritional value of foods, resulting in increased malnutrition
make land more profitable to use, resulting in eviction by landlords who want to profit from the land

require less labor to cultivate, resulting in a shift of the agricultural workforce into industrial labor