Northeast farmers weigh warming climate, drenched fields

"Climate change can easily intensify agricultural susceptibility, but also presents fresh, surprising opportunities," said David Wolfe, professor of plant and soil ecology at Cornell University and senior author of the paper.

For the past two decades, the Northeast has been getting warmer for longer periods of time. It also has seen a 71 percent increase in the frequency of extreme precipitation events -- more than any other region in the United States, according to the paper. Heavy rainfall, for example, increases the likelihood of diseases such as potato and tomato late blight, along with plant-root fungal problems that stress carrots and other root vegetables.

"Heavy rains not only cause disease problems, but can prevent farmers from having access to the fields to plant in spring or to harvest in fall," Wolfe said.

While warmer temperatures expand the agricultural production season, climate change warms oceans and creates a more energetic atmosphere. This, in turn, brings more rainfall, said Art DeGaetano, professor of climatology and director of the Northeast Regional Climate Center at Cornell. Such rainfall extremes are projected to continue through the current century, according to the paper.

For several years, the researchers examined the rainfall three weeks prior to the last frost. "The date of the last frost in the spring gets earlier and earlier. But that pushes you against the time when rainfall increases the most," said DeGaetano.

Fresh market vegetable grower profit is based on reaching markets early, when the crop's value is greatest. Delayed planting due to wet spring soils can have negative financial effects. Farmers can try planting a field even when it is wet, but using heavy farm equipment compacts soil and decreases its ability to hold water, diminishing yield potential.