Non-Fiction

According to farmer Justin Isherwood, gauging precisely how much to water a vegetable crop “approaches high-energy physics.” He looks skyward and lists the variables, starting with the obvious: rainfall, air temperature, humidity, soil composition. Also, wind speed, the phase of the plant’s growth cycle, where moisture settles, the slope of the land and whether a hedge or forest abuts the field. After decades in the business, decisions become almost intuitive. But along with external factors, a farmer weighs one important internal factor—how much he’s willing to gamble.

“Without irrigation, you’re taking a risk,” says Isherwood, who grows corn, peas, soybeans, pearl millet and potatoes near Plover, Wisconsin.