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Does corn still need rescuing?

Published July 23, 2015

URBANA, Ill. - The 2015 Illinois corn crop continues to develop on schedule, with 75 percent of the crop having reached silking by July 19. But the crop condition rating continues its steady downward trend, with the good plus excellent percentage now at 55 percent, down from its high of 79 percent at the end of May, said a University of Illinois crop scientist.

“Virtually all of this decline is due to standing water, past or present,” said Emerson Nafziger. “Rainfall frequency and amount has moderated some, but parts of western Illinois have received more than 6 inches so far in July.”

Nafziger added that growing degree accumulations since May 1 are running close to average for the whole state. “With planting a little ahead of normal this year, we can expect the crop to reach maturity beginning in early September or even late August,” he said.

Soil samples taken at tasseling at several sites from a nitrogen tracking project (funded by the Illinois Nutrient Research and Education Council) show that soil nitrogen levels have fallen considerably in recent weeks to levels at or below 50 lb nitrogen per acre in the top two feet of soil.

For the crop that is well past pollination, the number of kernels developing per ear is an indicator of maximum yield potential. According to Nafziger, crops with badly damaged root systems have, in most cases been showing pale or yellow leaves, death of lower leaves, and stunting, and either show no ears at all or have very low numbers of kernels.

“Their yield potential is low and can’t be improved,” he said.

In some cases, Nafziger said that the crop is only now starting to show loss of green color or yellowing, including lower leaf firing that may be moving up the plant. Some of this is occurring in parts of Illinois that have started to dry out where crops are expected to start recovering. This still seems to be occurring mostly in lower parts of fields, where water may have stood temporarily, perhaps several weeks ago, he noted.

“It seems logical to think that nitrogen deficiency developing now in fields where standing water hasn’t been a big concern is due to loss of nitrogen finally showing up as the plant continues to take up nitrogen,” Nafziger said. “There certainly might be some of that happening.”

Another possibility, he added, is that limitations of the root system from earlier damage are only now showing up, especially as surface soils start to dry and roots start to draw water from a little deeper in the soil.

Can we know which is the case, and is there anything we can still do about it?

“Either of the situations might mean the crop could respond to nitrogen applied to the surface, as long as the nitrogen can get into the plant. Before spending the equivalent of about 10 bushels of corn to apply urea by air, though, it would be good to try to assess the yield potential and to try to figure out if the crop is in good enough condition with enough kernels to make a return on the investment likely,” Nafziger said. “There’s no sure indicator of the potential of the crop to respond, but as a start, it should have most leaves still intact and around 450 to 500 kernels developing per ear.”

If a decision is made to apply more nitrogen to a field, the rate should be restricted to no more than 40-45 lb and the nitrogen should be applied as soon as possible, he added. “Protecting urea with Agrotain should help reduce volatility, but if urea stays on the surface long enough (without enough rain to move it into the soil), it is not going to get into the plant to do much good anyway.”

Foliar nitrogen is another possible source of nitrogen. The lower rate of nitrogen applied (usually 10 lb per acre or less) might be enough to carry the crop until its roots can take up more nitrogen from the soil, Nafziger explained. “With any source, the idea is to keep deficiency from advancing. The amount of green leaf area is closely tied to grainfilling rate. Dribbling UAN could work, but getting it into tall corn without delay in fields with wet spots might be difficult.”

Even if temporary nitrogen deficiency can be relieved by supplemental nitrogen applied this late, Nafziger added that nitrogen will not prove to be the most limiting factor in most fields. “Yield prospects will depend mostly on the ability of the root system to continue to take up water, and along with it some nitrogen, through the next month to 6 weeks,” he said. “Some of the developing nitrogen deficiency that we are seeing now may be the result of root systems that are damaged more than we think. In that case, even moderate stress as surface soils dry out might send plants into a downward spiral.

“There’s no good diagnostic for root system intactness, but pulling a few plants might provide a hint. If root systems seem small, shallow, or have darkened areas and dead root tips, the prognosis isn’t great,” he added.

“Things are looking better in parts of the state or fields where water hasn’t stood recently and where roots are getting some oxygen. Aside from the downpours, the weather continues to be good, without high temperatures so far. More low-humidity days would help, but humid days with sunshine are still helping the crop,” Nafziger said. “It’s not 2014, when temperatures this time of year were well below normal. But kernel set should at least be normal in undamaged parts of fields. That means they have the potential for good yields at least

Illinois releases strategy to reduce nutrient pollution in the Gulf

Published July 22, 2015

URBANA, Ill. - Illinois may be hundreds of miles from the Gulf of Mexico, but it’s a key contributor to the “dead zone,” a section of water the size of Connecticut devoid of oxygen that forms every summer. The culprit is millions of pounds of nutrients from farm fields, city streets and wastewater treatment plants entering the Gulf each year through the Mississippi River system.

Now the state of Illinois has just released a plan—the Illinois Nutrient Loss Reduction Strategy—to keep those nutrients out of the water.

The collaborative effort began almost two years ago in response to the federal 2008 Gulf of Mexico Action Plan, which calls for all 12 states in the Mississippi River Basin to develop plans to reduce nutrient losses to the Gulf. The process was spearheaded by the Illinois EPA and the Department of Agriculture and facilitated by Illinois Water Resources Center (IWRC) and Illinois-Indiana Sea Grant (IISG).

“It’s the most comprehensive and integrated approach to nutrient loss reduction in the state’s history,” said Brian Miller, director of IISG and IWRC. “But what really sets the plan apart is how it was developed. Government agencies, agricultural producers and commodity groups, non-profit organizations, scientists, and wastewater treatment professionals were all at the table working together to create this strategy.”

The approach outlines a set of voluntary and mandatory practices for both urban and agricultural sources for reducing the primary drivers of the algal blooms—phosphorus and nitrogen—that  lower oxygen levels. By targeting the most critical areas and building on existing state and industry programs, these practices are expected to ultimately reduce the amount of nutrients reaching Illinois waterways by 45 percent.

Led by researchers at the University of Illinois, the study uncovered numerous cost-effective practices for reducing nutrient losses. At the heart of the strategy is a scientific assessment that used state and federal data to calculate Illinois’s current nutrient losses and determine where they’re coming from.

The plan for wastewater treatment plants is relatively straightforward. The state had already begun to cap the amount of phosphorus they are allowed to release, restrictions that will likely be expanded under the new plan. The strategy also calls for sewage plants to investigate new treatment technologies that could lower phosphorus levels enough to prevent algal blooms in nearby waterways. 

For farmers and others working in agriculture, the options are a little broader. Most of the recommended practices, such as installing buffer strips along streambanks to filter runoff, planting cover crops to absorb nutrients, and adjusting nitrogen fertilizing practices have been used successfully in Illinois for years.   

“There is no silver bullet for reducing nutrients,” said Mark David, a University of Illinois biogeochemist and one of the researchers behind the scientific assessment. “It is going to take at least one new management practice on every acre of agricultural land to meet the state’s reduction goals.”



Controlled burns increase invasive grass in hardwood forests

Published July 21, 2015
grad student taking measurements
University of Illinois graduate student Stephanie Wagner measuring soil moisture.

URBANA, Ill. – Controlled burning is widely used to maintain biodiversity and enhance regeneration of important deciduous tree species such as oak and hickory, but a recent University of Illinois study found that this practice also increases the growth of an aggressive species of invasive grass.

Microstegium vimineum (also called Japanese stiltgrass or Nepalese browntop) is an abundant non-native grass in southern Illinois where the study was conducted.

“We found that fire promotes the recruitment and growth of M. vimineum, particularly under moist soil conditions,” said U of I landscape and ecosystem ecologist Jennifer Fraterrigo. “The Shawnee Hills region was never glaciated. Consequently, there are many places on the landscape that collect moisture and are highly vulnerable to invasion,” she said. “Burning these areas will likely result in large invasions if seeds are present.  In drier areas, burning has a weaker effect so invasions will be less severe.”  

In the study, burning increased grass biomass by 214 percent in wetter sites compared to 135 percent in drier sites.

M. vimineum can produce a dense carpet of growth that shades out tree seedlings and other resident plants,” Fraterrigo said. “It also competes well for nitrogen, thereby limiting the amount available of this nutrient to other species. Unfortunately, there do not appear to be many herbivores that eat this particular grass. So once it is established, it can be difficult to eradicate.”

Fraterrigo said that although most plants in deciduous forests are perennials, M. vimineum is an annual grass that produces copious amounts of tiny seeds that can be easily moved by vehicles, wildlife, and even water.

“Following burning, uninvaded areas will be highly vulnerable to invasion by M. vimineum if there is a nearby seed source. Even without fire, these places may eventually be invaded, but fire can speed up the process and intensify the invasion,” Fraterrigo said.

“Invasion also alters fire behavior. The thatch from dead grasses is highly flammable and increases fire temperature. Hotter fires may result in reduced survival rates for tree seedlings and germination rates for seeds banked in the soil.”

Fraterrigo hopes that this research will create an awareness that invasion is a potential side effect of burning. “Fire is one of the best management tools that land managers have at their disposal so we can’t expect managers not to burn at all,” Fraterrigo said. “Several rare native plant species thrive following controlled burning, which reduces dominant competitors. If we stop burning, those species may disappear.

“However, we need to be more cautious about when and where we use prescribed fire,” she said. “And we may need to combine fire with other management techniques to prevent large invasions from happening. Harvesting is labor intensive and costly, but using herbicides post-fire may lessen the extent to which fire promotes invasion.”  

“Positive feedbacks between fire and non-native grass invasion in temperate deciduous forests “ by Stephanie Wagner and Jennifer Fraterrigo was published in Forest Ecology and Management.

The research was supported by the National Institute of Food and Agriculture,  the U.S. Department of Agriculture, McIntire-Stennis Program, and the University of Illinois.





Soybean supply-and-demand tug of war

Published July 20, 2015

URBANA, Ill. – The November 2015 soybean futures traded to a low of about $8.96 on June 15, rebounded to $10.45 on July 14, and are currently trading near $9.90. According to University of Illinois agricultural economist Darrel Good, the volatility in prices reflects the market’s reaction to generally positive supply factors and some negative demand factors.

“On the supply side, the smaller-than-expected June 1 stocks estimate resulted in the USDA lowering the projection of 2014-15 marketing year-ending stocks to 255 million bushels in the July 10 World Agricultural Supply and Demand Estimates (WASDE) report ,” Good said. “That is 75 million bushels less than projected a month earlier and 220 million bushels less than projected in the fall of 2014. The June 30 USDA Acreage report indicated that harvested acreage of soybeans this year would be about 700,000 acres more than projected based on the planting intentions reported in March.

“However, there is a general consensus that not all of the intended acreage was actually planted due to extremely wet conditions in Missouri, Illinois, Indiana, and Ohio,” Good said. “In addition, flood damage may result in more than the usual amount of abandonment of acreage that did get planted. Those same conditions are also expected to result in an average U.S. soybean yield below the projection of 46 bushels in the July 10 WASDE report. In short, the 2015 crop is expected to be smaller than the current USDA projection of 3.885 billion bushels, but expectations are in a wide range.”

The USDA will release the first survey-based production forecast in the Crop Production report to be released on August 12. That report will reflect the results of the re-survey of soybean planted and harvested acreage in a few states.

“Consumption of old-crop soybeans remains strong and on track to reach the record levels currently projected,” Good said. “The National Oilseed Processors Association reported that the crush by its members in June 2015 was 20 percent larger than in June 2014. Crush in July and August needs to be about 7.5 percent larger than that of a year earlier in order for the marketing-year crush to reach the current USDA projection of 1.83 billion bushels. With about 6.5 weeks left in the 2014-15 marketing year, exports need to average about five million bushels per week in order to reach the current USDA projection of 1.825 billion bushels. That is less than the 8.4 million bushel average of weekly export inspections for the seven weeks ended July 16. Unshipped sales of 94 million bushels as of July 9 were sufficient to supply the necessary shipments.”

Good said the concern about soybean demand centers on potential export demand for the 2015 crop. The USDA currently projects 2015-16 marketing-year exports at 1.775 billion bushels, only 50 million bushels less than the record-large exports expected of the current year.

As of July 9, the USDA reported that only about 252 million bushels of soybeans have been sold for export during the upcoming marketing year. Sales are at the lowest level for that date since 2009 and are only about half as large as the average level of sales on that date in the previous three years. Current new-crop sales represent 14 percent of the projected exports for the upcoming marketing year. In the previous three years, sales at this time of year accounted for 25 to 41 percent of the marketing-year total exports. Sales to China, by far the largest customer for U.S. soybeans, stood at only 89.5 million bushels as of July 9 this year. Sales to unknown destinations, which likely include China, totaled 120 million bushels. In the previous three years, combined sales to China and unknown destinations averaged 457 million bushels, compared to only 209.5 million bushels this year.

“It is possible that the slow pace of new-crop export sales so far this year reflects a shift away from the recent seasonal pattern of export sales back to the pattern that prevailed during the period from 2006 through 2010,” Good said. “During those five years, new- crop export sales as of about July 9 accounted for an average of only 14 percent of marketing-year exports.

“If the pattern has shifted, then sales for the upcoming marketing year are currently on track with the USDA projection,” Good said. “The concern, however, is that the slow pace of export sales so far this year may be reflecting the loss of market share to lower-priced South American soybeans. The trade, for example, has reported large export sales of South American soybeans for delivery early in the 2016 calendar year.”

The current USDA projections are for year-ending stocks of U.S. soybeans to increase from 255 million bushels this year to 425 million bushels next year. “Even if the crop is smaller than currently projected, supplies should be fully adequate to meet expected consumption during the year ahead,” Good said. “At the projected level of consumption, the crop would have to be 170 million bushels smaller than currently projected in order to prevent a buildup of stocks and 275 million bushels smaller to reduce year-ending stocks to 150 million bushels. If export demand is weaker than projected, an even smaller crop would be required before U.S. supplies were small enough to require some rationing,” he said.

Good added that confirmation of smaller U.S. production prospects in the August 12 USDA Crop Production report might result in some price strength from current levels. A combination of smaller-than-expected production and improved export sales may be required to push prices above recent highs.