The economic support structure for agriculture is based on producing more food without taking into account its quality or the environmental damage caused. Subsidizing the use of pesticides harms the health of human and other species and builds up the resistance of the pests. Heavy irrigation aggravates floods, salinization and waterborne diseases. In Latin America millions of hectares of tropical forest, despite its rapid pasture deterioration and low carrying capacity, have been lost to subsidized ranching investments. Conventional farming does not currently bear the cost of cleaning nitrates out of the water resulting from use of fertilizers, or of loss of soil through soil erosion, or of destruction of habitats. Such costs are however absorbed, or avoided, in unsubsidized organic farming but which is nevertheless handicapped in competing with subsidized conventional farming. An organic farm avoids the use of agrochemicals by the use of rotation of crops in a fertility building cycle. It is the cost of this cycle that undermines the economics of organic production because between 40 and 60% of the land at any one time has to be devoted to "non-productive" fertility building (or fertility maintenance). But it is precisely this rotational factor that prevents environmental damage.
Despite US $6.1 billion in annual subsidies for fertilizers and irrigation, the prairie region of the USA (responsible for 23% of USA agricultural production) is becoming progressively more difficult to farm.