A recap of the Badger Crop Connect webinar on July 28, 2023
Since May much of Wisconsin has faced drought. While some areas got spotty summer thunderstorms other areas have not. The scarcity of rainfall and unrelenting heat means that since the first Badger Crop Connect Drought Webinar in June the drought has gotten worse in parts of Wisconsin. State experts came back in Part 2 of the webinar to provide continuing information related to the impacts, measures to be taken, and potential consequences to corn, soybean, and forage crops as well as update on the drought, disease and pest management and the resources available from FSA in drought affected counties. Look at the July 28, 2023, webinar’s highlights and recording below.
Are we still in a flash drought? Status of the 2023 cropping season
Joe Lauer UW-Madison Corn Agronomist Extension Specialist
Corn is pollinating all over the state of Wisconsin. Normally in Wisconsin, this could be anywhere from July 15 to August 5th for most varieties. It’s the most critical period for the corn life cycle. Joe Lauer noted that at the Arlington research station growing degree unit accumulation is slightly above average, but rainfall is low at only 11 inches since April 1st. It normally takes 20-24 inches of rainfall to produce a 200-bushel corn crop. Currently, corn plants are in, or near reproductive stages across the state; during these stages, corn is using around 1.5-2 inches of rain per week.
Drought has caused a delay in tasselling, and it’s creating a shortened window for pollination. We also have had hot temperatures and pollen is not viable over 95 degrees F. During these reproductive stages the corn plant is determining the number of kernels it will develop along the length of the ear as well as the kernel weight. Watch the webinar to learn more about checking the pollination success of drought-stressed corn.
Wisconsin’s state of soybean and small grains
Shawn Connley UW-Madison Soybean and Small Grains Extension Specialist
The wheat harvested so far has been excellent, 100 bu/ac averages in southern Wisconsin with high test weight. This was mostly from low disease pressure because it was so dry. Many oats were planted later than normal, and this came with challenges for the crop of lower test weight, yield, and higher weed presence.
The early season drought stress has not affected the soybean crop thus far. Soybeans are better able to compensate for dry periods due to phenotypic plasticity and their ability to flower and pollinate over a period of four to six weeks. However, they still generally require 18-24 inches of precipitation for a high-yielding crop. Will we get the 9” of rain needed to finish off the crop this season?
If you are in need of emergency forage, you can watch the webinar to learn what the best stages are to harvest the soybean as forage. Phytophthora has been found in several areas that received heavy rains and had standing water or highly saturated soils recently. The most important management practice for this fungal disease is to keep track of where it shows up and plant resistant varieties. Finally have you experienced any recent hail damage, spider mites, or soybean aphids like northern Wisconsin hear what Shawn has to say about what to do.
Managing drought stress in forage systems
Marta Kohman UW-Madison Forage Systems Agroecology State Specialist
Do you know why some forages are more drought tolerant than others. What is occurring to the crop after cutting that affects yield and quality? Do you have enough forage stored? Around 31% of USA alfalfa hay acreage is experiencing some level of drought. Laboratory analysis during drought will be important information to utilize to feed, sell or buy. Looking for rescue forage options, harvest soybeans, or you can still plant oats, forage rye, by mid-August and get 4000-6000 lbs DM/acre.
Finally, the webinar alerts farmers to watch out for potential forage health issues- prussic acid poisoning and nitrate toxicity. Get the symptoms from the webinar recording or links below.
– Drought stress in alfalfa areas (click on “Livestock & Forage”, and then on the “Map”): https://agindrought.unl.edu/
– Nitrate poisoning in cattle (some information on prussic acid as well): https://www.uaex.uada.edu/farm-ranch/animals-forages/beef-cattle/nitrate-poisoning-in-cattle.aspx
– Heat stress management in dairy: https://dairy.extension.wisc.edu/files/2021/02/Animal-Handling-during-Heat-Stress.pdf
Fertility Management in Dry Conditions
John Jones UW-Madison Researcher
Drought is not common in Wisconsin and John Jones wants everyone to be aware of what soil fertility is most affected during and after drought.
First nitrogen carryover is common following a drought N, due to low crop removal. Along with N carryover Dr. Jones also shared data showing how on average corn will remove 30 lbs./ac and 18 lbs./ac less of K and P respectively during a drought year compared to an average year. Soil is better able to supply N in wet years.
Second, soil water is needed to move nutrients! Potassium(K) deficiency is very prevalent this year, because K is very affected by no water, especially in low K testing soils. This year’s crop variability means variable crop uptake. Soil tests should be taken when soil moisture returns to a near-normal state and carry-over nutrients should be factored into next year’s fertility plan. Thus, there is an opportunity for zone soil sampling and VRT applications in the next crop season.
Wisconsin Drought Update
Steve Varvus State Climatologist
Compared to the June 8 Badger Crop Drought webinar, July 28 is a lot worse. Steve noted that the drought severity index was one of the most useful tools for comparing current conditions to the past. Since the year 2000 only two other years, 2005, and 2012 have been as dry as this year. Extremely dry air masses have been present in the state of Wisconsin since May (the low humidity) resulting in Wisconsin having recorded its 3rd driest May- June period (Statewide average 3.5” worst in the nation). This is only 46% of the normal rainfall we get.
Seeing local drought? Check out the links below on how to submit local drought impacts to the weather service. What’s been good is the dry air masses without humidity allow for cool nights. We also had the worst air in the world on June 27 due to Canadian wildfire smoke, but this is not a major factor affecting crop health.
See what state climatologist predicts for the rest of the growing season in the webinar.
Wisconsin State Climatology Office: https://www.aos.wisc.edu/~sco/
Condition Monitoring Observer Reports (CMOR):
Wisconsin CoCoRaHS Network monitoring reports: https://www.cocorahs.org/Content.aspx?page=condition
National Integrated Drought Information System: https://www.drought.gov/
- select Wisconsin in the “By Location” drop-down menu and then select Hay, Soybean, or Corn in the “By Sector” drop-down menu.
US Agricultural Commodities in Drought: https://agindrought.unl.edu/
- select Row Crops, Livestock and Forage, or Specialty Crops and then select information as Data, Table, or Map.
National Agricultural Statistics Service (Crop Progress & Condition Weekly Reports):
FSA Drought Assistance Programs
John Palmer USDA
Due to the drought, automatic Secretary of Agriculture disaster designations have been triggered in some Wisconsin counties. Learn if you live in one of those counties by listening to John Palmers webinar presentation. He explains CRP emergency haying and grazing, emergency production loss loans (for at least 30% crop loss), Assistance for water, feed, livestock transport related to grazed livestock, and forage disaster program.
John Palmer covered the USDA’s drought response and federal assistance programs. The most popular and likely most utilized program is release for CRP land for grazing or haying without a monetary penalty. To use CRP ground for haying or grazing, producers must live in a county experiencing a D2 drought, and they must receive permission from their local FSA office.
Find a local FSA center locater link. https://www.farmers.gov/working-with-us/service-center-locator
In-season Pest Management Updates
Josh Kamps Extension Crops Educator
Josh reminded us to evaluate corn rootworm damage on roots, especially in fields with continuous or second year corn. Beetle populations may target late planted or late emerged corn fields and could result in higher populations in the following years. Josh encouraged growers to utilize the apps “Tar Spotter” and “Spore Caster” to help aid in predicting the incidence of tar spot and white mold respectively. Weed escapes and populations should be scouted now until the end of the growing season to help determine harvest strategies and next year’s crop plan. Check for local insect issues by reviewing the weekly DATCP trapping report (link below).
An investment of 20-30 minutes in combine cleaning of the head, feeder house, rock trap, tailings elevator and rear axle can reduce weed seeds by over 70% before entering the next field or when cleaning up at the end of the season. Learn more about cleaning a combine.
Figure 1. The distribution of foreign material, and possibly weed seeds, by percentage in various areas of the combine following soybean harvest. Adapted from: Hanna, H.M et al. (2009).
Image 1. Palmer amaranth plant
Field notes program: https://datcp.wi.gov/Pages/Programs_Services/FieldNotesNewsletter.aspx
Wisconsin Crop Manager: https://ipcm.wisc.edu/wcm/