Why are corn yields declining in Virginia?

There is no doubt corn yields across America have gone up over the past 50-60 years.

Progress in corn yields has been nothing short of phenomenal, but is that still the case in the Upper Southeast?

At a recent meeting of the Virginia Grain Growers Association, Virginia Tech Small Grains Specialist Wade Thomason raised some interesting questions about corn yield trends in his state.

In Virginia, from 2000 to 2011, Thomason says over that 10 year period of time Virginia corn yields have declined by two bushels per acre per year. Most of the growers in attendance agreed they have flat or slightly declining corn yields.

Clearly that trend doesn’t apply to some Virginia corn growers. David Hula, who farms along the James River near Charles City, Va., broke all known Southeast corn production yield records last year with 429 bushels per acre.

Over the past five years, corn yields in Virginia have averaged 102 bushels per acre. In North Carolina, the five-year average stands at 106 bushels per acre. Clearly these numbers fall significantly short of the national corn trend. Similar up and down production trends can be found in other Southeast states.

The National Corn Growers Coalition, established in 2008 by the National Corn Growers Association, makes a poignant case for the productivity of corn: “Farmers today grow five times as much corn as they did in the 1930s — on 20 percent less land. That is 13 million acres, or 20,000 square miles, twice the size of Massachusetts. The yield per acre has skyrocketed from 24 bushels in 1931 to 154 now, or a six-fold gain.

Thomason says the decline in corn production in Virginia is mostly weather related. “I work every year with corn varieties, and I know yield based on varieties is going up. I think there have been similar advances in production technology, so about the only variable left is weather,” he says.

He asked the question: Do we need drought tolerant corn varieties? His yes answer got a few amens from the farmers in attendance.

Perhaps a better question may have been: Do we need irrigation?

At a recent cotton meeting, long-time South Carolina grower Gil Rodgers was a part of a panel talking about irrigation. Rogers has a large row crop farming operation in the PeeDee area of South Carolina and much of his crop land is irrigated.

“The best crop we can grow under irrigation is corn. It consistently produces high yields and, if prices remain good, it’s the crop you can count on most to make money.”

University of Georgia Researcher Dewey Lee has several years of data on irrigated and non-irrigated corn that support the South Carolina grower’s comments. Over a 10-year period from 1997 until 2008, Georgia corn growers with irrigation averaged 152 bushels per acre — slightly higher than the national average for that time period. Dryland corn growers averaged 73 bushels per acre, less than half the national average.

Wade Thomason’s assessment that drought tolerant corn will help Virginia corn growers, and growers throughout the Southeast, is clearly true. However, it is likely adding irrigation will have a bigger, more immediate impact on yields.

Obviously every grower doesn’t have the topography, field size or shape or water or financial resources available to add irrigation to every field. However, irrigation is one answer to sagging corn yields.

Good management and good soil also play a key role. Last year Jim and Jay Justice grew 289 bushels of dryland corn per acre, garnering national honors for their crop. They also farm along the James River near Bremo Bluff, Va.

Nationwide, in 2012 corn growers are expected to plant the largest crop since 1937, when 97.2 million acres were planted. Most of that production will be in the Midwest and most of it not irrigated and none of it planted to drought tolerant varieties.

Why take such a risk on dryland corn? The answer is simple — money. In 2010 corn prices averaged $5.30 a bushel — that’s $1.30 a bushel higher than corn prices had ever been up to that point in time. When all is said and done, 2011 prices will likely average close to $6 a bushel. Hence, the answer as to why U.S. farmers are expected to plant about 98 million acres of corn in 2012.

As is the case in the Southeast, the more acres of corn planted, the higher the percentage of the crop that will be planted on marginal land. The combination of marginal land, lack of irrigation, and fluctuations in weather patterns in the Southeast has trumped advances in corn production technologies and new and improved varieties.

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TAGS: Corn
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