Even if Iowa receives the amount of moisture needed in the coming months to be at or above average for the year, Iowa State University Extension Climatologist Elwynn Taylor does not expect that to fully relieve the state of its drought conditions.
Taylor was the first of four speakers Thursday at the final day of the Farm News Ag Show and drew a crowd of more than 100 people as he spoke about the weather and crop outlook for 2013 and beyond.
"In the past water year, there was 21 inches of average precipitation for central Iowa. That is the driest we have had for a year since 1988 when it was 20.5," said Taylor. "When it's been this dry it takes more than a year to recover. The rain doesn't even recover in one year, let alone the soil."
-Messenger photo by Hans Madsen
Mark Wigans, of Renwick, stands in the doorway of the filled-to-capacity meeting room in the Career Education Building at Iowa Central Community College to listen to Elwynn Taylor, an Iowa State University agricultural meteorologist, speak at the Farm News Ag Show Thursday morning.
To illustrate how dry Iowa's fields are, Taylor asked for a show of hands on how many farmers in attendance had water running through their tiles compared to how many did not.
Around 25 had water; 22 did not.
"That's about 50-50, but normally 80 to 90 percent would have tiles running," said Taylor. "We are all shy of moisture."
Since the beginning of the new water year, Oct. 1, he said the state has seen less than 5 percent of its usual amount of precipitation.
"A small part of the state had what we would expect since Oct. 1, but we are at less than 5 percent of the average."
Taylor said the states in the Corn Belt are all below average in rainfall, while states to the northwest are seeing above average precipitation.
"Montana has three times the moisture it normally sees. They're up 300 percent and that is not the pattern I wanted to see. It is dry from Texas to the Minnesota border."
According to Taylor, the increased moisture in the west is a sign of La Nina, which has likely been to blame for the recent dry conditions in the midwest.
"That is a symptom of a developing La Nina, and La Nina is what has caused problems the past two years."
Taylor also discussed ground and soil moisture and how crops survive during a dry year.
"The average root depth is 5 feet," said Taylor, "and there is about 2 inches of water in each foot. You need to have that 10 inches of water the day you plant and the crops need about 20 inches to have an average year, or 25 to have a record yield. That doesn't guarantee it, but it makes it possible. You need to get that other 10 inches at the right time and right amounts during the growing season."
The national average trend for a corn crop is 160 bushels per acre, he said, and that for many years the trend was above average.
"National yield was above trend for six consecutive years," said Taylor, "but the national yield fell to 122 bushels per acre. We are in a third year and I would expect there to be a fourth year of below-trend years."
Taylor said the previous times there were consecutive below-average years, a strong La Nina weather pattern was part of the problem.
"Each time it was because of a strong, multiyear La Nina event and this has been the second strongest La Nina on record in history."