Lester R. Brown writes: In the early spring this year, US farmers were on their way to planting some 96m acres in corn, the most in 75 years. A warm early spring got the crop off to a great start. Analysts were predicting the largest corn harvest on record.

The United States is the leading producer and exporter of corn, the world’s feedgrain. At home, corn accounts for four-fifths of the US grain harvest. Internationally, the US corn crop exceeds China’s rice and wheat harvests combined. Among the big three grains – corn, wheat, and rice – corn is now the leader, with production well above that of wheat and nearly double that of rice.

The corn plant is as sensitive as it is productive. Thirsty and fast-growing, it is vulnerable to both extreme heat and drought. At elevated temperatures, the corn plant, which is normally so productive, goes into thermal shock.

As spring turned into summer, the thermometer began to rise across the corn belt. In St Louis, Missouri, in the southern corn belt, the temperature in late June and early July climbed to 100F or higher 10 days in a row. For the past several weeks, the corn belt has been blanketed with dehydrating heat.

Weekly drought maps published by the University of Nebraska show the drought-stricken area spreading across more and more of the country until, by mid-July, it engulfed virtually the entire corn belt. Soil moisture readings in the corn belt are now among the lowest ever recorded. [Continue reading…]