Farmers adjust to new weather norm
By Janet Kubat Willette
jkubat@agrinews.com
Date Modified: 02/02/2012 9:14 AM
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KASSON, Minn. — It's getting wetter and warmer in south central Minnesota.
Every 10 years, the climatology service updates the normals for temperature and precipitation, said Tom Hoverstad, a scientist at the Southern Research and Outreach Center in Waseca.
The 30-year normals, now based on 1981 to 2010 actual weather, show an annual increase in temperature of 0.9 degrees and an annual increase in precipitation of 1.02 inches.
January temperatures are 2.2 degrees warmer under the new normal, with April, September, November and December all a degree or more warmer warmer with the new normal.
The greatest increase in precipitation comes in June and September, up 0.47 inches and 0.48 inches respectively.
"We're used to wild swings in the weather," Hoverstad said at Winter Crops Day in Kasson last week. "What I think relates more to you guys is the new precipitation normals. We have more rainfall to deal with."
More of that rainfall comes in summertime thunderstorms, which bring a greater chance of large hail or flash flooding, he said.
Some farm impacts of the new climate normals include:
• Insect pest populations that are able to overwinter.
• Possible impact on pest migration patterns.
• Heat stress on livestock.
• Many plant diseases favor warm temperatures and high humidity.
"From here on, it's like reading you my diary," Hoverstad said.
He puts out a weekly weather and crop bulletin during the growing season and pulls a line from each one for a crop year in review.
He starts putting out the bulletin about the time the ice is off the lakes, somewhere around mid April.
April 2011 started warm and wet and ended cold and wet. Rain fell on 21 of 30 days. By month's end, 1 percent of state's corn was planted and none of the soybeans. Small grains were only 3 percent planted. The month ended 2.3 degrees colder than normal and 1.25 inches wetter than normal.
Frequent rains continued into May, with four days the longest rain free period. High temperatures went from 36 degrees to 92 degrees in eight days.
Waseca set a new state record for highest May dew point at 78 degrees. Crops were planted in marginal conditions.
On May 16, 47 percent of the state's corn was planted and 9 percent of the soybeans.
By June 5, farmers had made a lot of planting progress. Ninety-five percent of the state's corn was planted and 75 percent of the soybeans.
Extreme heat, including record highs topping 100 degrees marked early June.
The crop caught up on growing degree units. Some yellow was seen in corn fields, which Hoverstad said was likely caused by the crops growing so fast because of ideal conditions.
July continued the trend of warm temperatures, both day and night. A low of 79 degrees on July 19 broke the old record in Waseca set in 1915 for the highest low. Numerous dew point records were set across the state, including an 88 degree dew point in Moorhead. It was the fifth warmest and 10th wettest July on record.
In August, temperatures moderated, coming in at only 0.2 degrees higher than normal, but the rainfall stopped. It was the fifth driest August on record. Small grain harvest was disappointing.
Come Sept. 1, all corn was dented. Soybeans stayed green longer than normal and a frost on Sept. 15 brought the growing season to an end. The frost was two weeks earlier than normal. September 2011 was the driest September since 1968.
Dry weather continued into October. There were no harvest delays and soybeans got too dry. Corn was also dry coming right out the field.
Temperatures topped 80 degrees for seven consecutive days, coming close to the eight-day record.
Dry soil conditions made for difficult tillage and anhydrous ammonia applications. A lot of big clods were left in fields.
It appears the freeze and thaw cycles of this winter have already helped the clods to break apart, Hoverstad said.
He's not worried about the dry soil moisture, as there's still the potential for gain by spring. It could be like 1976, which was a dry fall followed by a wet year in 1977, but there's no correlation between fall soil moisture and yields going back 20 years.