Surplus water hits fields

DES MOINES — Statewide reports from the USDA show a considerable surplus of topsoil and subsoil moisture in Southeast Iowa for the first time in recent memory, as excessive rainfall washes through Iowa fields.

The latest Crop Progress & Condition Report showed 16% of Southeast Iowa’s fields reporting a “surplus” of topsoil moisture July 13 and 20, but the number grew from 7% to 11% in the same period for subsoil moisture. Statewide averages were higher, at 21% and 17% surplus, respectively. State Climatologist Justin Glisan said in the same report that such excesses likely contributed to countless flash flood warnings issued over the weekend, “due to higher intensity rainfall on top of saturated soil profiles.”

Rain during the reporting period came down heavy but isolated, with torrents hitting some communities hard while others stayed mostly dry.

An Iowa Environmental Mesonet data station in Wellman for example, measured 1.33 more inches of rainfall on July 19 than another in Crawfordsville, on the opposite end of Washington County. And neither clocked more than a few drops of precipitation July 16-18, when a National Weather Service monitor at the Washington Municipal Airport — in the center of the same county — logged a handful of late-night and early-morning downpours totaling over 2 inches.

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Farmers say the excessive precipitation could have damaged crops and hay bales where streams overran their banks and flooded nearby fields.

“Some low-lying areas are getting way more water than they need, it’s different than it’s been for several years because we’ve been in, I would say, a fairly dry cycle,” said Lance Bell, president of the Washington Keokuk County Corn & Soybean Growers. “If the water was deep enough to cover them up, it probably ruined them. But if they just got really wet feet for a few days and then dried out, not so much … whether it was really bad, or just a little bit detrimental, that remains to be seen.”

Humidity threatens disease pressure

With hot, humid conditions now in the forecast, Iowa State Extension Office Agronomist Rebecca Vittetoe said she was keeping an eye out for gray leaf spots and southern rust, two fungi known to damage Midwestern corn crops in the current climate.

“Recently we’ve been too warm for tar spot. The fields we are finding it in, I’m guessing that infection happened back in June,” she said in an email. “There is a lot of talk around tar spot, or there has been, especially since it was first found in a field in Poweshiek County back in June. And since it’s still a newer disease/what we’ve seen it can do in fields if we have the right conditions, it is on the minds of many.

“[Gray leaf spots and southern rust] are two diseases I’m definitely keeping my eyes on here. We’ve had favorable conditions for them. If we see them showing up in fields, since they are both caused by fungal pathogens, a fungicide may be warranted. Typically, where we see the most benefit from a fungicide application if it’s needed [is] when the corn is between R1 (silking) and R3 (milk) stage.”

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That window is closing fast, however.

According to the USDA’s Monday Crop Progress & Conditions report, 71% of Southeast Iowa’s corn crop has reached the silking stage. But 13% has already reached the dough stage, also known as R4, immediately after the milk stage.

Growers say the sense of time pressure is magnified by muddy cropland, which can block access for heavy farm equipment needed to apply fungicides.

“Timing is kind of important,” Bell said. “And if you’re using a ground rig — meaning you’re driving something through the field — if it gets too muddy and you can’t get through it, then that becomes a problem.”

Also at play are prices.

Fungicide is expensive -roughly $30-40 an acre — and with low market rates for grain commodities, some producers worry it’s not worth the cost.

“With the current price of corn, you’re going to need eight to 10 bushels of gain just to break even, and that’s possible but it’s a lot to ask,” said Jeff Cuddeback, a farmer in Washington County. “Just on our own farm, my dad and I have differing opinions on what to do about that … he’s not excited about spending the money when crop prices are this low. While I don’t like spending the money, I would rather spend it in hopes of preserving the bushels we have out there.”

Corn and soy quality hold up for now

For the moment, corn’s quality seems to be holding up. According to the USDA, 86% of corn crops are in “good” or “excellent” condition statewide. Another 11% are currently “fair,” while 3% are “poor” or “very poor.”

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Soybeans paint a similar picture. The USDA said 74% of Southeast Iowa’s soybeans had bloomed, and 44% had set pods as of July 20. Statewide, 80% of the crop is in “good” or “excellent” condition, while 17% is holding up “fair” and 3% is “poor” or “extremely poor.”

Regional commodity quality stats were not included in the report.

As of the July 20 USDA report, other farm-grown products showed high quality marks as well, with over 80% of hay and oat crops in good or excellent condition, as well as 79% of pastures.

Those numbers might sink moving forward, however, as data pours in following the latest round of flash floods across the state.

In addition to potential water damage, Cuddeback said he had some concerns about nitrogen loss affecting corn crops amid the series of midsummer showers.

“The risk is leeching of nitrogen, out of the soil profile,” he said. “The way to rectify that would be to come back with a late-season application, which I’ve only ever had to do one time … that particular year, as I recall, it did pay. But it’s an expensive application with an uncertain outcome.”

Comments: Kalen.McCain@southeastiowaunion.com