Drought-struck areas of the U.S. Plains winter-wheat belt need a deluge of rain and snow this winter to fully recharge parched farmland, an unlikely scenario that means wheat, corn and soybean crops could face a rough new season.
While the worst drought in roughly half a century is slowly loosening its grip on the United States, meteorologists and agronomists warn that the threat has not passed.
Wheat farmers now sowing their last winter seeds, and corn and soybean growers making planting plans for spring, are haunted by the worrisome fact that parts of Nebraska, Kansas and other key agricultural states have the lowest levels of moisture in years. Indeed, Nebraska recorded the driest June, July and August on record and the third-driest September ever, according to preliminary data from the National Climatic Data Center.
Some areas would need 5 to 6 feet of snow on top of more than 15 inches of rainfall over the next few months just to get back to normal, say climate experts. It typically takes about 10 inches or more of snow to make one inch of water.
That would not mark record amounts of precipitation, but would provide much more than normal - and more than can easily be dealt with.
"It's an insane amount of snowfall that would be required... among the top five snowfalls in history," said Al Dutcher, a climatologist with the National Drought Mitigation Center in Nebraska. "That would be a nightmare."
The heavy rains that hit the eastern United States this week when Hurricane Sandy roared ashore had little to no relief to offer for drought-hit states like Nebraska.
The National Oceanic and Atmospheric Administration (NOAA) in October predicted an "enhanced chance" of below normal precipitation for the middle section of the country this winter.
DRY, DRY NEBRASKA
Soil moisture not only is necessary for growth. It also helps insulate plant roots from killing freezes and helps protect a crop from fierce winds that can topple weak stands.
Without adequate soil moisture plants either die outright, or yield poorly, if at all. But just how much rain and snow is required to recharge soil moisture levels to adequate and surplus levels varies widely across the country.
There are so many variables, includng the condition of the soil, and the rate at which water penetrates the soil, that an equal number of inches of rain on different fields the same year, or upon the same field in different years, may still result in material differences in the quantity of water taken into and retained by the soil, according to agricultural researchers.