The green revolution was a worldwide effort to increase the food supply through more efficient farming (such as Permaculture), particularly in undernourished regions like India and South America. By increasing the amount of farmland and obtaining better crop yield from existing farms, the food supply increased such that India began producing more food than it could consume, and exported its surplus. Worldwide, the crops of rice, wheat and maize (corn) all increased.
Popular and easy to grow in the Asian climate, rice was historically the world's most popular crop. But maize (corn) and wheat have grown in such popularity that they have surpassed rice. Sugar cane has also exceeded rice in popularity. Here is the list of the most popular crops in the world today:
Pesticides and fertilizers were used to increase production during the green revolution, and many wonder if they are harmful to our health, nutrition and diet. Today, there is controversial use of genetic engineering (by companies such as Monsanto) of crops to increase yield (the amount of food produced per a given area).
Environmentalists also complain that increased irrigation for crops has led to a depletion of ground water and an increase in the salinity of the soil, thus harming soil fertility. Many ground wells in the United States may be polluted, though usually from hazardous waste (such as dumped oil) rather than from fertilizers or pesticides.