July rains provide moisture boost for area crops

July 18, 2016

Kim Ukura, Morris Sun Tribune

Storms that rolled across Minnesota in early July may have brought the "million dollar rain" area farmers needed to keep this year's growing season on track for a successful harvest this fall.

Farmers were able to get planting on time this spring, and good soil moisture at the start of the growing season helped crops get started, said Curt Reese, a scientist in agronomy and soil science at the West Central Research and Outreach Center in Morris.

"The start of the season was fairly optimal," Reese said. "Most farmers have low wet areas that one tends to go around or mud them in — we really didn't see that this year, and even in drier ground you had good soil moisture."

The biggest weather problem early in the season, said Reese, was a frost event on May 15 and 16 that damaged recently planted corn.

"Most of the corn around the area was frozen off, but at that point the growing point was below the ground and it recovered — it took awhile, but it's certainly starting to look pretty good," Reese said.

Although lawns and backyard gardens struggled early in the summer due to lack of rain, Reese said dry weather in May and June did not cause much damage to corn and soybean crops. In fact, the dry weather may have benefitted these crops by forcing them to develop a deeper root system.

When there is low rainfall, growing crops need to dig deep to get the moisture they need, Reese said. These deep root systems help make crops more resilient in late-July and August, when their moisture needs are higher.

"If you're going to have a dry period during your crop growth, you're better off to have it early," said Reese.

That said, heavy rainfall in early July came at just the right time for area crops. The WCROC recorded 4.51 inches of rain on July 5, with another .59 inches on July 6, for a total of 5.1 inches for the two day storm. Rainfall over the weekend added another 3.31 inches between July 10 and July 12.

Only 5.73 inches of rain fell from April to June 2016, 3.53 inches below normal for that time period. In all of 2016, precipitation is down 4.57 inches from normal, with just 7.29 inches recorded in the first six months of the year.

"Hopefully the weather pattern has changed so we'll start picking up our weekly rains," said Reese. "We were certainly getting dry."

Reese said his biggest concern for crops this season is small grain crops like wheat, oats and barley. Lack of moisture and warm weather during development means small grains are maturing faster than usual. In general, this makes it less likely there will be a good yield, Reese said.

"A lot of farmers said the wheat was heading earlier, so there's a concern there," said Reese. "There's also a concern for just plain running out of moisture."

Regional temperatures have been slightly higher than average for most of the season, creating a good number of recorded Growing Degree Days. The average between April and June is 923 GDD. This year, the area has seen 984 GDD.

Growing Degree Days are a measurement of accumulated temperature or heat. It is measured by subtracting 50 degrees, the base temperature for corn growth, from the average temperature for the day. The maximum average temperature is 86 degrees, the highest temperature for corn growth.

A day that averaged 80 degrees, for example, would accumulate 30 GDD. In June, July and August, the average is about 20 GDD per day. The biggest impact on increasing GDD for the year is warm overnight temperatures, Reese said.

Going forward, Reese said the region needs warm (but not hot) temperatures and timely rains to ensure good crop yields this fall.

Reese also encouraged area farmers to be aware of weeds and other pests that may be a problem in the region. Farmers should be looking for soybean nematodes and aphids, which can cause problems for area crops.

And although it's too late to spray for some weeds like waterhemp, a Roundup resistant plant common in the area, Reese said farmers can look for it this year and plan for best management practices in 2017.

"Spend some time scouting fields," Reese said. "Those type of problems are going to be here next year, and we need to adjust our practices to help mitigate the problems next year."