Tuesday, November 20, 2018

2018 Wisconsin Corn Performance Trials: Grain - Silage - Specialty - Organic

The 2018 Wisconsin Corn Performance Trial results are now available on the web. Every year, the University of Wisconsin Extension-Madison and College of Agricultural and Life Sciences conduct a corn evaluation program. The purpose of this program is to provide unbiased performance comparisons of hybrid seed corn available in Wisconsin. These results are a ''Consumer Report'' for commercial corn hybrids. The trials evaluate grain, silage, and systems including organic, transgenic and refugia systems. A one bushel per acre increase by Wisconsin corn farmers increases farm income $8 to $32 million dollars

To view or download a copy of the 2018 results, navigate to the Wisconsin Corn Agronomy website at http://corn.agronomy.wisc.edu/ or see http://corn.agronomy.wisc.edu/HT/

Thursday, September 6, 2018

Handling Flooded and Down Corn at Silage and Grain Harvest

Rain events during August produced localized flooding affecting numerous corn fields. Recent high winds combined with saturated soils have resulted in lodged corn. All this is occurring at the dent growth stage (R5) as we head into corn silage harvest season. Heavy silage harvest equipment can further damage soils by causing compaction which could influence next year's crop.

Flooded corn

Flood water from streams and silt can be a source of pathogens. Flooded corn grain is "adulterated" grain. Farmers are strongly encouraged to work closely with their veterinarian and animal nutritionist when determining which vaccination and feeding protocol to use to further protect the herd from possible health issues associated with feeding flooded crop material. Flooded crops should be stored separately from the rest of your feed. In cases of production problems, this allows for feeding or disposal options without affecting your good feed.

Lodged corn

Fields that have lodged at denting (R5) might "goose-neck" back upright if they are still green. However, high yielding heavy ears may prevent the stalks from straightening at all. Fields should respond to any straightening within 7-10 days

Silage harvest

Some things to consider as we head into corn silage harvest season:
  1. Safety first.
  2. Water saturated soils will slow down plant dry-down rate, especially with cooler temperatures. Allowing a little more time for the field to dry out will help alleviate potential soil compaction.
  3. Regardless of lodging, the key management driver is plant moisture.Yield is no longer a concern. Target fields at the ideal moisture content of the storage structure. Bag silos have the greatest moisture range (60 to 70%) and may be best option when the field is variable. 
  4. Good fermentation will help with preservation. Consider a silage inoculant, however, balance the cost of the product with the loss expected in in the field. Don't throw good money after bad.
  5. Use a Kemper head and go against the direction in which it leans.
  6. Reach down low. Run the head as close to the ground as possible. Be wary of rocks and uneven terrain.
  7. Make sure the kernel processor is adjusted correctly. Kernel processing allows for grain that might be more mature extending the harvest window and allowing the soil to dry more avoiding compaction.
Grain harvest

Identify fields that are at greatest risk and harvest these fields first. Fields which experienced late season stress or disease would be prime candidates for early harvest.
  1. Safety first
  2. Reduce ground speed. Slow down and adjust gathering chain and snapping roll speed to match combine speed
  3. Go against the grain. Combine corn the opposite direction from which it leans.
  4. Catch the corn. Adjust gathering chains and snapping plate as close as possible to the stalks.
  5. Reach down low. Run the head as close to the ground as possible. Be wary of rocks and uneven terrain.
  6. Be ready. Scout fields to anticipate harvest problems.
Further Reading

Flooding Effects on Corn

Lodging in Corn

Lauer, J. 2016. Wet Fall Weather, Flooding, Kernel Sprouting and Molds. Agronomy Advice, Field Crops 28.49-127.

Lauer, J. 2008. Flooding Impacts on Corn Growth and Yield. Agronomy Advice. June 2008 Field Crops 28.49-56.

Wednesday, August 8, 2018

Corn Nitrogen Fixation - Getting closer to a reality

Corn is a major user of nitrogen fertilizer. Nitrogen fertilizer production is an energy intensive process that uses 1-2% of the total global energy supply and produces an equivalent share of greenhouse gases. For nearly a century, the "holy grail" for this crop and other cereals has been to engineer a mechanism for biological fixation of atmospheric nitrogen.

It looks like we are one step closer. In a recent publication in PLOS Biology, researchers found that atmospheric nitrogen fixation contributed 29-82% of the nitrogen nutrition  of a Mexican corn landrace. The plants are able to do this by producing a sugar-rich mucilage on aerial roots. The mucilage provides a home for a number of nitrogen-fixing bacteria species. This trait appears to be an ancient trait since it is also found in a close corn relative called teosinte.

Scientists are still a long way from nitrogen fixing commercial hybrids of corn adapted to the Midwest U.S. Corn Belt. But, the fact that biological nitrogen fixation can occur on corn plants opens up many novel avenues for future research and improve nitrogen use efficiency.

Further Reading

Van Deynze, A., P. Zamora, P.-M. Delaux, C. Heitmann, D. Jayaraman, S. Rajasekar, D. Graham, J. Maeda, D. Gibson, K.D. Schwartz, A.M. Berry, S. Bhatnagar, G. Jospin, A. Darling, R. Jeannotte, J. Lopez, B.C. Weimer, J.A. Eisen, H.-Y. Shapiro, J.-M. Ané, and A.B. Bennett. 2018. Nitrogen fixation in a landrace of maize is supported by a mucilage-associated diazotrophic microbiota. PLOS Biology 16:e2006352.