The success of the drive to introduce new high-yield varieties tends to exacerbate the instability of the international crop trade in agricultural commodities; import demand from previously low-producing countries leading to price falls and surpluses in exporting countries. The resulting shifts in trade patterns make price stabilization more difficult. Although regulating the growth of plants is as old as farming itself, the use of chemical compounds in agriculture has been one critical aspect of the contemporary explosion of crop yields. It remains to be fully seen what environmental effects these unnatural manipulations of the food chain will have in the long run.
The enormous short-term increase in grain yields were made possible by high-yield crop varieties, pesticides, fertilisers and mechanization. Hailed as the solution to the world's food problem, but the green revolution has created more problems than it has solved. By far, the manufacturers of pesticides, fertilisers and farm equipment grew riches by the green revolution. The only farmers who benefited were the relatively rich ones who could afford the seeds, pesticides, fertilisers, tractors and irrigation equipment. The crops involved in the green revolution such as rice and wheat were often not the ones wanted by the masses of farmers. The green revolution was aimed at cash crops decreasing the availability of food crops. It led to a galloping erosion of native plant varieties in favour of highly inbred imports. Mechanization decreased the number of jobs available in the countryside. The varieties of seeds involved required good soil and plentiful water. The farmers on small plots of marginal land who grew staples like beans, cassava, yam, millet, sorghum and maize were driven into deeper poverty and increased dependence on large landholders or moneylenders. Land speculation caused land prices to rise, and peasants renting land found their rents soaring. Many were forced to leave the land swelling the ranks of urban slum-dwellers. Land ownership became more concentrated.