WORTHINGTON -- As the thunder rolled and the rain began to fall Monday night and continued intermittently during the day on Tuesday, farmers across southwest Minnesota were calling the much needed moisture "a million dollar rain."
But is it too little too late for crops that have been void of rainfall and subject to high heat and humidity in recent weeks?
Not at all, according to University of Minnesota Extension Crops Educator Lizabeth Stahl of the Worthington Regional Extension Center.
Granted, this year's yields may not be as abundant as those harvested last fall, but southwest Minnesota crop farmers still have a chance to bring in good yields.
"Overall, we've got something to work with," Stahl said. "We can come out with decent yields."
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That's unlike the severe drought areas of northwest Minnesota and central South Dakota, where crops have burned up because of the lack of rain.
Precipitation statistics for southwest Minnesota on Saturday showed the region a trace up to three inches short of moisture, whereas areas to the north are three to six inches short. Stahl attributed the region's wet spring with saving this year's crops from real severe damage in recent weeks. The crops were able to tap into some moisture, and Tuesday's rains helped offset the dwindling supply.
Southwest Minnesota was officially moved into the moderate drought category on July 25. The designation came just after the region's corn crops completed tasseling, pollination and fertilization. Now, as both the corn and soybean plants work on filling out ears and pods, any rain that comes will be greatly appreciated.
"Most of the corn was successfully pollinated," Stahl said.
Farmers who are concerned about the success of pollination in their corn crop can do a simple check by opening up the ear and checking to see if the silk shakes loose. Silks that are loose prove that the plant has pollinated, she added.
Although top yields may no longer be attainable, at this point it's impossible to predict what kind of yield farmers will see come harvest. Crop data shows that corn, if under severe moisture stress for a period of four days, will result in yield reductions of 40 to 50 percent. Soybeans, on the other hand, would show a 19 percent yield reduction during the same four-day period.
"Most of our beans didn't see that visible moisture stress, unless there were pockets in the field where there are sandier soils," Stahl said.
Soybeans are just now in the stage of filling pods -- a critical time when adequate, timely rains are needed. The same can be said for the corn crop, as ears are in the blister stage.
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"It's a real critical time for corn and soybeans right now," Stahl said, adding that for the crops to continue to do well, corn needs about three-tenths of an inch of water per day, while soybeans need about a quarter of an inch of water on days when the temperature exceeds 90 degrees. On days when the temperature is cooler, the plant will need less water.
As farmers remain concerned about drought stress to their corn and soybean fields, they must continue to monitor the presence of pests and diseases. Stahl said one of the main concerns this year is the spider mite, an insect that attacks soybean fields.
"A lot of people are spraying for aphids, but they have to watch out for spider mites, too," Stahl said.
She added that while many farmers have waited to spray for aphids until their fields have reached threshold levels, some are spraying earlier than recommended.
"If you're spraying for aphids before you need to, you could create a problem by flaring up spider mites," she continued.
Though corn and soybean fields dominate southwest Minnesota's landscape, the area's alfalfa fields may also be impacted by the lack of rainfall. Stahl said alfalfa under drought stress will appear shorter, and the number of stems will be less than during an average year of moisture. However, the leaf-to-stem ratio increases under drought stress, which helps maintain the alfalfa's quality.
"If you don't have very much alfalfa out there, skip the cutting, let it grow, and cut it later," Stahl said. "If the crop is thin but it looks like you've got a decent yield, then you could harvest on schedule."
