Spring has sprung! Preparations for planting across the state are in full swing. Conditions over the last 30 days have been unseasonably warm across the Midwest with positive departures of anywhere from two to four degrees. Early March had a good stretch of dry conditions; the second half of the month experienced a more active storm track in which rainfall (and some snow) fell every few days. With the recent wetness, the last thirty days were also wetter-than-normal.
Soils remain wet from fall 2019, which was the seventh wettest in 148 years of statewide observational records, following the 12th wettest year on record. Taken with 2018, the two-calendar year stretch has been the wettest two-year period on record. There is a silver lining, though. Conditions moving into the 2020 planting season are better than they were at this time last year. Additionally, the above average temperatures and some windy days also helped to dry soils out beginning in early March.
Looking at the Climate Prediction Center’s (CPC) short-term outlooks into mid-April, probabilities indicate very high probabilities of unseasonable coldness with a slight chance of wetter-than-normal conditions. Overnight lows are expected to dip down into the 20s this weekend and into early next week.
While these temperatures shouldn’t impact row crops since corn and soybean planting hasn’t started quite yet, specialty horticulture crops may be impacted as well as forage crops. For forage crops like alfalfa, there is the potential to see some frosted leaves in established stands, but plants should be fine. New alfalfa seedings that may be up have very good frost tolerance due to two main factors. One is their proximity to the soil and the soil’s radiant heat relative to the colder air temperatures. The other is that seedlings have a rather high concentration of solutes (sugars and other compounds) in the cells that help lower its freezing point. If new seedings are frost damaged, they will first appear to wilt and then die over the following 3 to 5 days. As long as at least one set of leaves escapes damage, the plant should recover. Wait a week after the frost and estimate living plants per square foot. If more than 20 plants per square foot remain, the stand will survive in good shape. If there are fewer than 15 plants per square foot, consider interseeding more alfalfa into the stand.
The final April outlook from the CPC shows a slight decrease in the probability of wetter-than-normal conditions, which were found in the initial April outlook released in mid-March. The temperature signal also suggests higher chances of warmer-than-normal temperatures for much of Iowa. What we see in the April outlooks is mirrored in the April-May-June outlooks: elevated chances of warmer and wetter conditions.
Farmers should be mindful of soil conditions, given the current wetness across much of Iowa. Compaction issues are still a concern. Soil temperatures have been trending up across the state over the last few days with upper 40s and low 50s in western Iowa to upper 30s and low 40s in northeastern Iowa. Taken as a whole, farmers should be ready to go when short-term outlooks and forecast show windows of favorable weather.Category: Crop ProductionTags: weather outlookspring weatherJustin GlisanAuthors: Justin GlisanRebecca VittetoeCrop(s): CornMinor cropsSoybeanBiomass and ForageCover Crop
Whether you are thinking about trying strip-till or already using strip-till in your farming operation, the question of timing comes up—fall or spring? There are many factors that go into this decision, including availability of equipment and labor and weather and field conditions that change year to year. This question of fall or spring strip-tillage was the primary focus of a three-year study conducted from 2016 to 2018 at Iowa State University.
A commercial scale test was repeated each year on a minimum of 50 acres in a selected test field. The field site was rotated each year to incorporate varying production conditions into the test. All three fields were in a corn-on-corn rotation. The goal of this trial was to study the impact of varying strip-till timing and nutrient application.
Three treatments were replicated across each field in side-by-side strip trials to minimize the effects of spatial variability within the fields:
- Fall only strip-till with phosphorous and potassium (P&K) nutrient application.
- Spring only strip-till with P&K nutrient application.
- Fall and spring strip-till passes, with the P&K nutrients applied on the fall pass.
A coulter type strip-till machine was used for these studies (Figure 1). It used wavy coulter blades to till a 10-inch-wide zone, while incorporating dry fertilizer product evenly throughout the depth of the zone. This machine was set for 30-inch rows, and the zones were shifted 15 inches each season to be centered between the standing stocks from the previous season. The replacement rate of P&K was calculated for each field depending on crop removal from the previous year and target soil build levels. Monoammonium phosphate (MAP) and potash were used as the source of applied P&K for all fields.
Figure 1: Fall strip-till pass with a coulter style row unit. MAP and potash were applied and incorporated during the tillage pass.
While there were yield differences between the three test fields based on their inherent soil productivity and seasonal weather differences, there were no statistical differences between treatments within the same field (Figure 2). This provides growers with flexibility in the best timing for strip-till in their operation based on available labor and equipment. It also allows them to be flexible with the timing of strip-till year-to-year as weather and other operational factors change. If the fall season is late and wet or there is an early freeze, there is still an opportunity to do strip-till and nutrient application in the spring without substantial yield penalties.
Figure 2: Yield results of the multi-year strip-till timing study conducted at Iowa State University. This data shows no statistical difference between treatments within the same field, indicating that timing of strip-till and nutrient application can vary as needed to fit a given operation or crop year.
The flexibility of strip-till and nutrient application is key to making this system successful in any grower’s operation. It allows the grower to fit strip-till into their operation as it works best for them and change it year-to-year depending on weather and other operational factors.
Category: Crop ProductionTags: strip tillstrip tillageDigital Agapplication timingfertilizer applicationAuthors: Levi PowellMatt DarrRyan W Bergman
In 2019 Iowa had over 460,000 prevented plant acres. As we prepare for the 2020 growing season, one concern we sometimes hear about with prevented plant acres is fallow syndrome. Fallow syndrome happens when the populations of “good fungi” known as vesicular-arbuscular mycorrhizae (VAM) are reduced due to the lack of actively growing roots. These “good fungi” help with nutrient cycling and plant nutrient uptake, particularly for phosphorus (P) in corn. Fallow syndrome is only a concern if there was little to no plant growth in a field last year (i.e. no cover crop and no weeds).
To manage for fallow syndrome, these are our best recommendations based on the knowledge we have:
- If the field is to be planted to soybean, fallow syndrome is typically not a concern. Starter fertilizer is not suggested for soybean. If starter is used, it should not be placed in-furrow with soybean planting.
- If the field was under water for a considerable period of time (several months) last year, inoculating soybean with rhizobia may help with nodulation.
- For corn, research has been inconsistent regarding yield response with fertilizer application.
- If no P has been applied and fallow syndrome is suspected, suggestions have been to apply either a high P starter rate placed 2x2 (two inches beside and two inches below the seed) or a high P broadcast rate (approximately twice the normal recommended P rate) if soil tests are low and no starter equipment on the planter.
- If an annual P rate was applied in 2019 on acres that were prevented plant, a normal P starter rate placed 2x2 or in-furrow could help is fallow syndrome is suspected.
- If a 2-year rate of P was applied in 2019 on acres that were prevented plant, the additional need for P fertilizer is unlikely.
- Sometimes a yield response has occurred to a higher starter N rate (25 lb N/acre, away from the seed) rather than to P.
- If soils were flooded for a considerable time last growing season, check out the fact sheet “Flooded Soil Syndrome”.
- The University of Minnesota recently published the article “Spring Management of Prevent Plant Acres”, which shares some additional information on how to management prevented plant acres that either had cover crops planted on them or had no weed control management used. Please note that fertilizer recommendations vary from state to state. Thanks to Liz Stahl, Anna Cates, and Lisa Behnken for allowing us to share their article!
Special thanks to John Sawyer and Antonio Mallarino for their review and thoughtful additions.Category: Crop ProductionSoilsSoil FertilitySoil ManagementTags: prevented plantingfallow syndromesoil fertility issuessoil fertilityAuthor: Rebecca VittetoeCrop(s): CornSoybean
Are You Getting the Most Out of Your Tractor?
Determining the proper ballast and tire pressure for your tractor should be a key part of spring equipment maintenance. Proper ballast and tire pressure will maximize traction and tire life while minimizing fuel consumption and compaction.
Ballasting a tractor is the act of adjusting the weight its frame to allow for optimal fuel efficiency and pulling power in the field based on the field operation. Most planters from the last decade are attached to the tractor’s three-point hitch or the rear drawbar. The rear axle often carries more of the planter’s weight in the field. This results in the tractor needing less rear ballast and transferring more ballast over the steer axle to pull the planter. In a tillage application, the tillage tool often has little to no tongue weight when the tool is engaged in the soil, requiring more weight on the rear of tractor to compensate for high draft load. Before altering the ballast or the front-rear weight ratio of the tractor, consider the following questions.
- Does the tractor have a mechanical front wheel (MFW) assist?
- The front-rear weight ratio will be higher on an MFW tractor than a 2-wheel drive model.
- What is the gross weight of the towed implement?
- The tractor needs enough ballast to properly stop the implement while being towed at transportation speeds.
- What is the operational speed of the implement, both in the field and on the road?
- Higher field speed implements often require more ballast to limit wheel slip during operations. The same implement might require 2000 pounds less if towed 3 miles per hour slower.
- Does additional weight transfer to the tractor when the implement is in the transportation position?
- A centerfold planter shows how additional weight can be added to the rear axle when in transport.
- Is the implement balanced in a way that the tongue will put additional weight on the rear axle?
- When a manure tank is loaded, a significant amount of tongue weight is added to the tractor from the tank.
A guideline to the correct ratio between the front and rear axle weights is determined by the Original Equipment Manufacturer (OEM) and can typically be found in the back of the owner’s manual. A worksheet may be found in the owner’s manual to help calculate ballast changes, like this example from John Deere.
If the manual is not available, the PM2089G factsheet available in the ISU Extension Store is a good reference for general recommendations by tractor type (Table 1). This factsheet also provides information on required weight per horsepower based on tractor type and operating speed.
Front-to-rear axle weight ratio as percentage of total weight
Towed / drawbar
% Front / % Rear
% Front / % Rear
% Front / % Rear
Table 1. Provides general recommendations on tractor ballasting by tractor type. The ballast distribution can change front to back up to 10% depending on the type of implement used.
Setting Tire Pressures
Tractor tire pressure should be set according to the tire manufacturer’s specification. Proper tire inflation significantly improves the traction of the machine and reduces soil compaction and operator fatigue. Several factors should be considered when setting tire pressures. If the pressure is too high, the tire’s contact with the soil is reduced. The tractor can experience a higher wheel-to-ground slip and machine bouncing can occur, reducing the pulling power of the tractor. Over-inflation can cause decreased tractor productivity and fuel-efficiency, as well as increased soil compaction. A higher wheel slip can equal higher fuel consumption. Over-inflation also reduces the tire’s longevity.
Over-inflation can be detected in the center of the tire where it has the most contact with the ground. The center lugs are often worn and shorter than the lugs near the outer edge of the tire. If the tire has experiencing a sustained duration of wheel slippage, the tire will often show signs of wear in the lugs as thin lines or groves where the tire was scraped past hard objects like rocks and hard packed soils.
Underinflated tires can also cause uneven tire wear and can ultimately end in tire failure. Underinflated tires show wear in the shoulder and sidewalls of the tire. Extremely low tire inflation can damage the tractor rim. Underinflated tires are extremely unstable and can lead to tractor rollovers.
LSW (Low Sidewall) tires can also be used. Compared to traditional tires, these have a larger rim and slimmer sidewall that allows them to operate at lower pressures while maintaining weight carrying capacity. This reduces soil compaction and minimizes issues with hopping under high load conditions.
To set the tire pressure, know what speed you tend to operate and the load on each axle. Axle weights can typically be found in the back of the owner’s manual or by weighing the tractor. Consider aftermarket additions to the tractor, such as saddle tanks for carrying liquid fertilizer, when making the axle weight determination. Most elevators or grain cooperatives have large enough scales to weigh a tractor and will often let you use them free of charge if you are a customer. OEM tire manufacturers offer load and inflation tables used to set tire pressure based on the size of the tire, the tractor’s intended speed, and weight applied to the axle (Figure 1).
Figure 1: It is important to inflate tires to the proper pressure based on the machine and axle load. As the axle load increases for a specific tire, it will require more pressure to safely handle the load. (Table courtesy of Titan International).
Example: Based on the table above, we will calculate the needed tire pressures for a given machine setup. Assume we are operating a MFW tractor with dual tires on all 4 wheels (8 tires total). The rear tires are a 480/80R50. The rear axle of the tractor has 16,000 pounds of weight on it, measured before the implement was attached. When an implement is added to the 3-point hitch, the rear axle weight increases to 23,000 pounds. We can determine the per tire load by dividing 23,000 by 4 since we have 4 rear tires. We need to be able to support 5,750 pounds per rear tire. Looking at the chart above for our tire size with duals, we would need a minimum pressure of 17 PSI to support this machine setup.
In the age of smartphones and mobile technology, some tire manufacturers have created web-based resources to calculate the correct inflation pressure for many agricultural applications (Titan/Goodyear App , Firestone App). Select the correct application for the tire (spraying, harvesting, tillage, etc.) and input the configuration of the machine—single, dual or triple tires on each side of the axle. A drop-down list of different tires sizes and a box to select the weight of the machine will appear. The calculator will produce the recommended inflation pressure for each tire.Category: Equipment and MachineryTags: tire inflationEquipmentplanting equipmentDigital AgAuthors: Ben CovingtonRyan W Bergman
Wisconsin has been proudly known as America’s Dairyland for many years. However, recent data on dairy farms in the Driftless Region (Figure 1) are suggesting times are changing in the dairy industry for Western Wisconsin and surrounding states. According to the USDA NASS, the number of dairy farms in the Driftless Region with less than 100 head of cattle have been on the decline over the past 10-15 years. On the flip side, farms with 100+ head of cattle have been increasing . The largest dairy farms (>500 head) more than doubled their number between 2007 and 2017. In total, the number of dairy farms showed a slight (<10%) decrease over the same period (Figure 2). This is, in essence, a “consolidation” of dairy farms, where although the total number of dairy farms has not changed drastically, there is a pronounced shift from small dairies to large dairies occurring in this region.
The consolidation of dairy farms in the Driftless Region has been accompanied by substantial changes in the area of annual row crops planted in the region. Over 14 HUC-8 levels watersheds in the Driftless Region (all of which drain into a Mississippi River tributary), a spatial analysis of USDA Cropland Data Layer data indicates that annual crop (corn, soybeans, and wheat) acreage increased in every watershed between 2006 and 2017 (Figure 3a). Across the watersheds, row crop acreage increased by 20,000 or more acres, which for some watersheds was a >30% increase from 2006 acreage (Figure 3b). Most of the land that was converted to row crops came from grasslands & pastures (51.6%) or alfalfa (23.2%) (Figure 4). This reflects the dairy farm consolidation trends in that as the small dairies go out of business, less land is needed for pasture or alfalfa and may be converted to row crops. Another reason for the large increase in row crop acreage could be a strong biofuel market in the late 2000s, which increased the incentive to put more land into production [2,3].
So what are the environmental impacts of such changes? Research is currently underway to quantify the relationships between the trends in row crop acreage, annual precipitation, and regional hydrology that have been observed in the Driftless Region watersheds. We expect this work to be published in the near future. However, similar studies have shown the ways in which row cropping can influence the landscape and impact hydrologic processes. The steep topography of the Driftless Region makes any land that is utilized for row crops particularly vulnerable to soil erosion and compaction . This impacts the hydrologic cycle by reducing the ability of water to infiltrate into the soil profile, which in turn increases runoff [5,6]. With a shift from perennial vegetation to annual row crops (which has been the case with the Driftless Region over the past 10-15 years), there are now periods where the ground is fallow before planting/emergence and after harvest and is highly susceptible to erosion/runoff [5,6,7]. Along with the land cover changes, increases in annual precipitation were observed in the Driftless Region between 2006 and 2017 (Figure 5), which can act to enhance these effects [8,9]. Overall, these findings suggest that the result of an increase in row crop acreage and annual precipitation is an increase in the amount of water leaving the landscape into the waterways. Not only does this affect local hydrology, but in the case of the Driftless Region, it is likely to result in an increase in water, sediment, and nutrients leaving the region via the Mississippi River down to the Gulf of Mexico. Therefore, any future row crop expansion should be accompanied by careful management decisions motivated by both economic and environmental factors.
 USDA National Agricultural Statistics Service (NASS). Website: https://www.nass.usda.gov/.
 Lark, TJ, Salmon, JM, & Gibbs, HK (2015) ‘Cropland expansion outpaces agricultural and biofuels policies in the United States’, Environmental Research Letters, 10.
 Schilling, KE et al. (2008) ‘Impact of land use and land cover change on the water balance of a large agricultural watershed: Historical effects and future directions’, Water Resources Research, 44(7), pp. 1–12.
 Potter, KW (1991) ‘Hydrological impacts of changing land management practices in a moderate-sized agricultural catchment’, Water Resources Research, 27(5), pp. 845–855.
 Juckem, PF, et al. (2008) ‘Effects of climate and land management change on streamflow in the driftless area of Wisconsin’, Journal of Hydrology, 355(1–4), pp. 123–130.
 Knox, JC (2001) ‘Agricultural influence on landscape sensitivity in the Upper Mississippi River Valley’, Catena, 42(2–4), pp. 193–224.
 Zhang, YK and Schilling, KE (2006) ‘Increasing streamflow and baseflow in Mississippi River since the 1940 s: Effect of land use change’, Journal of Hydrology, 324(1–4), pp. 412–422.
 Rogger, M, et al. (2016) ‘Land use change impacts on floods at the catchment scale: Challenges and opportunities for future research’, Water Resources Research, 53, pp. 5209–5219.
 PRISM Climate Group, Oregon State University (2017) 'PRISM Climate Data' [online]. Website: http://prism.oregonstate.edu.Category: Crop ProductionTags: Driftless regionland use changeprecipitationhydrologydairy farmingAuthors: Josh BendorfEmily HeatonCrop(s): Corn
This year let’s all toss out planting windows for corn. Farmers should be focused on when soil conditions are prime to plant. Soil temperatures need to be on the rise; 50oF and rising. Planting 24-36 hours before a cold spell—regardless of how long—is putting your seed at risk of cold injury and reduced germination.
The critical corn planting date for Iowa is before May 18 and soybean is May 20; after which you can expect yield losses. Switching to a well-adapted maturity doesn’t pay off until after June 1 for corn, and about June 15 for soybean, but at that point, it would be more about reducing fall frost risk more than anything.
There might be some hope when it comes to variable rate seeding. Not necessarily from increasing yields, but from seed cost savings. Typical seeding rate response range for common hybrids is going to be 32,000-35,000 and 2,000-4,000 less, for economic seeding rate depending on seed costs. The weather and its interaction with topography and soil is a huge influencer on how variable rate seeding works. Dry weather typically means depressions and field areas that collect water can support higher seeding rates. However, if conditions are wet then upland areas and course soils can support higher seeding rates.
For soybean, using the same 125,000-140,000 seeding rate is still a solid recommendation. Farmers could possibly drop 25,000 on high productivity field areas. Stress areas from Soybean Cyst Nematode or iron deficiency chlorosis or similar may benefit from higher seeding rates, while areas with high white mold potential may benefit from lower seeding rates.
Row spacing on corn may have higher yields for 20” rows compared to 30” rows when yield potential is greater than 240 bu/ac. However, below 240 bu/ac, 20” and 30” rows are yield neutral. I’m quite confident of this for north of Hwy 30 and west of I-35. Less certain for southern Iowa.
The benefit would be that yield benefits could be realized in soybean (unless white mold potential is high), which could help pay for equipment changes. The problems are that a planter, combine head and tires are a huge capital expense and even a soybean yield response may not be able to cover those costs.
Check out the NEW Guide to Iowa Corn Planting.Category: Crop ProductionTags: CornSoybeanplanting dateseeding rateVariable rate seedingrow spacingAuthor: Mark LichtCrop(s): CornSoybean
Extension specialists in Iowa and Minnesota are collaborating to provide a series of short, daily webinars for farmers, ag professionals, Extension personnel and other interested parties from April 6 to April 10. The theme is “Essential Row Crop Management" for spring 2020, with a focus on key topics to be addressed prior to the planting season.
Each webinar will start at 1:00 p.m. with a 10 to 15 minute discussion followed by time for questions and answers. Since fieldwork and planting season is upon us, sessions will be limited to 30 minutes.
These webinars are free and open to all. Topics and presenters are listed below.
- April 6: “Top 3 tips for cover crop termination” with Meaghan Anderson, Extension Field Agronomist, Iowa State University Extension and Outreach
- April 7: “Grain storage management for spring” with Shawn Shouse, Extension Ag Engineer, Iowa State University Extension and Outreach
- April 8: “Management of fertilizer spread patterns” with Ryan Bergman, Program Coordinator, and Matt Darr, Professor, ISU Agricultural and Biosystems Engineering
- April 9: “Pre-emergence herbicide programs” with Lisa Behnken, Extension Educator, Crops, University of Minnesota.
- April 10: “Tillage options this spring” with Jodi DeJong-Hughes, Extension Educator, Water Resources, University of Minnesota
For more information about the series and to register, go to: https://extension.umn.edu/courses-and-events/essential-row-crop-management-online.
Once you register, you will be able to watch any or all of the webinars. If you cannot attend in person, a recording of each session will be available for viewing as soon as they are available. Additional resources on each topic will also be provided through the website above.Category: Crop ProductionGrain Handling and StorageSoilsWeedsTags: eventspring cover cropgrain storagespring tillagefertilizer applicationpreemergence herbicidesAuthors: Meaghan AndersonAngie Rieck-HinzCrop(s): CornSoybeanCover Crop
The USDA Sustainable Agriculture Research and Education (SARE) program, along with the Conservation Technology Information Center (CTIC) are once again sending out a national cover crop survey to farmers.
The survey is primarily geared to grain farmers and those that use cover crops, but it does have questions that any crop producer would find relevant. Farmers are asked to complete the online survey by April 12, 2020. CTIC is also providing VISA gift cards on a random basis to participants who complete the survey. If you would like to take this survey, please click through, or copy and paste this link: https://bit.ly/CCSurvey2020.
Category: Crop ProductionTags: Cover cropcover crop surveyAuthor: Mark LichtCrop(s): Cover Crop
The interactive monitor guide is available from ISU Extension at www.extension.iastate.edu/digitalag/monitors.
With the 2020 crop season approaching, ISU Extension has a tool available to help farmers, crop advisers and agronomists understand almost every machine display on the market, for everything from planting to harvest. The interactive monitor guide, available on the Extension website, offers step-by-step support for managing products, loading and executing variable rate prescription maps, setting up split planter configurations and exporting data.
The guide features drop-down menus for users to choose the operation they are doing—Harvest, Nitrogen, Planting or Wireless Data Transfer—and select the brand of their display, the display model and the function they want it to perform. The site will provide a guide for that specific need and walk the user through the process.
While the site is designed to be used on a mobile device for easy access in the field, it can also be used on a desktop computer to reference from home.
While most operators understand how to use their displays well, some of the finer details can be tricky when it comes to utilizing and exporting data. The online guide provides step-by-step instructions on how to operate the display for each brand and model.
If you are a crop adviser who works with multiple displays or a farmer wanting to master your own display, this interactive site can provide the knowledge and reference you need throughout the crop season. The website is updated periodically as manufacturers release software updates and new monitors to their product line.
For questions or more information about the website, email Ryan Bergman at email@example.com.Category: Equipment and MachineryTags: precision agAg TechnologyEquipmentmachineryAuthors: Ryan W BergmanChris Murphy
With the recent alterations we've all had to make in our lives in the wake of the Coronavirus pandemic, many of your offseason field days, meetings and/or conventions have either been canceled or suspended indefinitely. This could have put a damper on your plans to receive crop management updates from industry members, leaving you in disarray about where to go to now for information and resources.
Due to these worldly conditions, the Iowa State University Integrated Pest Management Program (IPM) has decided to extend its once-a-season offer of its Crop Scout Essentials: Pest Management Field Guides bundle, through April 30. This bundle contains all the resources you’ll need for addressing the pest management decisions facing your fields this year and for years to come. This value bundle gives you five field guides for the price of three: Soybean Diseases, Corn Diseases, Field Crop Insects, Corn and Soybean Field Guide and The Weed Management Guide.
With the new crop season just around the corner, we want you to be prepared for the yield-reducing disease, insect and weed challenges affecting your fields.
Extension field guides are great scouting resources and provide a wealth of information for identifying production issues affecting your operation. Whether you're a grower, certified crop advisor or an industry professional, Extension field guides are tailored to showcase best practices, scouting techniques and provide you with means-tested management options.
Should you be looking for bulk orders of these guides for a cheaper price, the Iowa State Extension Store offers bulk orders of the following guides: Soybean Diseases, Corn Diseases, Corn and Soybean Field Guide and the Weed Identification Field Guide.
Certified Crop Advisor Continuing Education Units
As a lot of offseason events have been canceled, it may be difficult to find ways to earn CEUs as a CCA. While not worth as much as a regular crop meeting, the Crop Protection Network (CPN) does offer CEUs for reviewing each of their 22 publications and passing the corresponding follow-up quizzes.
The Crop Protection Network also offers plenty of free, downloadable publications on diseases, fungicide efficacy tables and research advancements in crop-pest management.
Category: Crop ProductionInsects and MitesPesticide EducationPlant DiseasesWeedsHerbicide ResistanceTags: Crop Scout essentials bundlefield guidescrop managementIPMAuthor: Ethan StoetzerCrop(s): CornSoybean
Planting season will soon be upon us, despite the current pandemic. This ICM Blog will discuss a few key things to focus on regarding planter set-up as we approach the 2020 planting season. For a video version of this article, see Planter Maintenance and Set-up.
Proper planter set-up is critical for optimizing plant spacing no matter the color, age, or size of your planter. While newer equipment may allow us to plant in less than ideal conditions, I sometimes see those fields later in the year with interesting results—some good and some not. If you have not made adjustments to your planter set-up in the past few years, things to keep in mind include the following:
- Row cleaners come in various configurations. However, remember with row cleaners, the concept is to not till a trench. Instead the purpose of row cleaners is to only move aside any residue from prohibiting the double-disc openers from placing seed at the proper seeding depth. In other words, tickle the soil and don’t till a path. I often see seeding depth issues related to aggressive row cleaners in no-till corn planted into soybean stubble. If you are in a strip-till system, you may be more aggressive with the row cleaners. If planting into standing fall-planted cereal cover crops, I am hesitant to use row cleaners due to wrapping and plugging from the cereal crop.
- Single-row coulters function as a form of tillage ahead of the double-disc openers. There are several styles of single row coulters available and in most planting conditions some soil contact is desirable. The major challenge when using coulters is soil moisture and speed. The deeper we run coulters, the higher the risk of soil sticking to the coulters. Consequently, soil may be tossed from the row, especially as planter speed increases. This can result in shallower seed placement. Additionally, if soil sticks to the coulters, it can contribute to sidewall compaction.
- One can make the case that the double-disc openers are the single most important thing on your planter. The double-disc openers will allow proper seed depth and slice an opening to properly place the seed at the ideal planting depth. If you are not sure the last time you purchased new ones, I recommend you do some measuring to check for wear on the openers. With most planters, the double-disc openers should measure 15” in diameter; however, this can vary based on the brand. There should never be more than a ½” of wear. When worn openers are used, it typically results in “hair pinning” of residue causing shallow planting depth.
- If increasing planter speed, more down pressure is needed. How much more pressure depends on soil moisture conditions and residue cover. Take time to get out and check field conditions and planter settings to make sure the seed is getting placed at the proper depth. Make adjustments as needed. For more information see High Speed Planting Technology.
- There are numerous closing wheel and drag chain setups; however, their functions are the same: to provide proper seed-to-soil contact. This is critical to help with even crop emergence. Also, consider as planter speed increases, down-pressure should be increased. Almost any set-up can mash the seed slot closed; however, ask yourself “do you want the seed slot to open back up after it dries?” Again, taking time to check behind the planter and look for good seed-to-soil contact in the furrow, as well as potential issues like compaction or malformation of the seed furrow is worth the effort while planting.
Be sure to monitor seed depth while planting as all the technology in the world is no substitute for a pair of pliers and digging behind the planter. The technology is fabulous to watch and can greatly improve the capacity for most farmers. Nevertheless, it is still important to ground truth planter settings. Do not “set it and forget it” as soil conditions vary from field to field and even within a field. Take the time to make the proper adjustments.Category: Crop ProductionTags: plantingplanter adjustmentsplanterAuthor: Aaron Saeugling
The Crop Protection Network (CPN) has published its 2020 fungicide efficacy tables for foliar diseases of corn and soybean, and for seedling diseases of soybean. These three publications can be found at the CPN website, under resources and publications.
Plant pathologists from across the country, participating in several plant disease working groups, assembled these guides for the purpose of reporting the efficacy of various fungicides. The data used for calculating an efficacy rating was compiled from national fungicide trials published through Plant Disease Management Reports (American Phytopathological Society, APS) throughout 2019.
This is the third iteration of fungicide efficacy tables that CPN has produced. These resources are an imperative tool for farmers, agribusiness professionals, certified crop advisors (CCAs) and extension specialists as fungicide efficacy can change from year to year. Because the ratings are released every year, users of these tables are getting the most useful information possible, as a fungicide’s efficacy can vary from year to year, and region to region.
The ratings in each of the three guides are measuring the effectiveness of an active ingredient, and do not necessarily reflect yield increases or decreases as a result of application. An efficacy rating may depend on the rate of the fungicide applied. Combining active ingredients can protect against a broader spectrum of diseases, as well as reduce the potential for disease resistance. The ratings in the tables where calculated to serve only as a guide. It is an applicators legal responsibility to read and follow label directions. Tables include:
- Fungicide Efficacy for Control of Soybean Seedling Diseases
- Fungicide Efficacy for Control of Corn Diseases
- Fungicide Efficacy for Control of Soybean Foliar Diseases
In addition, CPN has also updated its Soybean Seedling Disease publication. This guide has been updated from its 2015 iteration, complete with photos, scouting measures and research updates. All of these publications can be found under the publications tab, within the CPN resource section, at cropprotectionnetwork.org.
CPN is a multi-state and international partnership of university and provincial extension specialists, and public and private professionals that provides unbiased, research-based information. Our goal is to communicate relevant information to farmers and agricultural personnel to help with decisions related to protecting field crops.Category: Crop ProductionTags: fungicidesfungicide efficacy tableAuthor: Ethan StoetzerCrop(s): CornSoybean
Due to COVID-19 and the need for social distancing, the Iowa State University Plant and Insect Diagnostic Clinic (PIDC) has made the decision to implement as much distance diagnostics as possible in order to greatly reduce the numbers of physical samples.
We have made this decision due to federal, state and university guidelines to protect the health of our staff and students, and because clinic staff will not be able to normally access campus or their workplace.
Therefore, before sending in a sample, please contact us through email at firstname.lastname@example.org. We will do as much distance diagnostics as possible at no charge. We will continue to evaluate the situation over the next weeks and months as the growing season will increase testing needs. Please keep watch on our social media pages (listed below) where we will give any updates and still provide you with your horticulture and gardening news.
Recently Iowa State University (ISU) completed a five-year study of high speed planting technology using the Precision Planting SpeedTube and the John Deere ExactEmerge seed meter and seed delivery system. Both planters provided excellent singulation and spacing of corn while planting up to 10 miles per hour (High Speed Planting Technology Article, Link 1).
In agriculture, it is rare that a single technology will provide a guaranteed yield response every year. Although there are examples like section control (Precision Ag Technology Savings Article, Link 2), most ag technologies provide different levels of yield and economic impact depending on the growing season. When considering the yield benefits of high speed planting, it’s important to consider two areas where this new technology has an opportunity to enhance yields in a given year.Plant Spacing and Skips
The most direct influence a planter row unit can have on yield is in its number of seed skips or unplanted seeds. A significant amount of skips will result in a net reduction in overall corn population. In testing conducted at ISU, we observed a significant increase in the number of skips at planting speeds of 7.5 miles per hour and greater when using a conventional vacuum seed meter, compared to a meter designed for high speed operation. The combination of skips produced at the seed meter and skips produced by excessive seed bounce in the drop tube often exceeded 10 percent for a conventional planter meter operating at 10 miles per hour.
Figure 1: Summary of corn skips for conventional and high-speed planting units. Conventional planters significantly increase the amount of skips as planter speed increases. High speed planters are able to maintain a low level of skips at all speeds up to 10 mph. High speed data presented includes both Precision Planting SpeedTube and John Deere ExactEmerge which both produce similar corn spacing results.
Increasing seed meter skips and seed bounce in the drop tube resulted in less consistent seed spacing. As previously discussed (High Speed Planting Technology Article, Link 1), the standard deviation of seed spacing increased proportionally as planter speed increased with conventional planters. Seed spacing with high speed planters was consistent at all speeds tested, up to 10 miles per hour.
During side-by-side comparisons in the same field planted with the same variety, we observed that high speed planters produced statistical yield advantages ranging from 0 to 3 bushels per acre. While not guaranteed to provide a positive yield response in a single year, improved spacing and reduced skips is a foundation to strong corn production, and high speed planting technology can deliver excellent results over a wider operating range than traditional planter row units.Timely Planting
The economic benefit of reduced skips and improved corn spacing are only achieved when planting at high speeds. When operated at the manufacturer-recommended speed of approximately 5 miles per hour, the majority of conventional planting systems can achieve high-quality spacing that will maximize yield.
Corn yield potential is influenced by planting date (Best Corn Planting Dates for Iowa, Link 3). Although the specific date range varies based on where you farm, all regions of the corn belt have date ranges that maximize yield potential. As corn planting extends beyond the optimal planting window, corn yield potential can drop by as much as 3 to 5 percent per week.
If you are one week beyond your optimal window for 20 percent of your corn acres, it will have a net impact of approximately $6 per acre across your farm. For a 1,000-acre corn producer with 200 acres of late planted corn, the average economic impact will be $6,000. While this is certainly not guaranteed in a specific year, there is strong agronomic data to suggest this economic impact is real over the long term.
There are multiple ways to increase planting capacity and plant more corn within the optimal window. This includes using a larger planter, operating multiple planters or planting at a higher ground speed. Each producer decides how to optimize their own operation to balance logistics, cost and labor capacity. For many, choosing high speed planting technology is a way to maintain current equipment size while planting more acres per hour with the same amount of labor.
Recommendations for planting capacity are heavily driven by risk management. Producers should consider if they are planning for a typical planting season, or an overly wet and narrow planting window that may occur once every five years. This decision will be different based on the risk management practices of each producer. High speed planting technologies are simply another way to manage risk, provide growers with another tool for managing narrow planting windows and get more corn planted within the optimal planting period for their region.Soybean Survival Rate & Yield
In the high speed planting study conducted at ISU (High Speed Planting Technology Article, Link 1), we found soybean survival rates at harvest are higher when they are planted with a system that can singulate and maintain good spacing, even at high planting populations. The yield advantage of improved singulation and survival rate in soybeans ranged from 0 to 2 bushels per acre in a given year. Results where similar across seeding rates ranging from 100,000 to 160,000 seeds per acre which highlights soybean yield flex across populations. While this result does not suggest a guaranteed financial gain from yield improvement, it does highlight the potential of high speed planting systems, and specifically the improved seed delivery systems, to enable reduced soybean seeding rates to achieve the same at harvest plant density and yield.Equipment and MachineryTags: high speed plantingyield considerationsAuthors: Matt DarrRyan W Bergman
Many farmers put grain in the bin wetter than normal last fall and were somewhat rescued by the cold weather that allowed them to put cold grain into storage. In the coming weeks as spring starts to bring warmer temperatures, grain held through the winter at a high moisture content should be dried or marketed as soon as possible to prevent quality loss and mold growth.
Monitor grain condition and act fast if hot spots, a musty/moldy smell, or elevated CO2 levels (above 600 ppm and rising) are observed. Grain held this winter at a very high moisture content (above 20%) may have already used its safe allowable storage life. For this grain, it may not be advised to attempt to store it any longer after drying it this spring. Observe the allowable storage time for grain in this recent blog post and be sure to account for a shorter allowable storage time with low test weight and low quality grain.
Wet grain should be dried as soon as spring temperatures start to warm. Conditions become suitable for natural air/low temperature bin drying when average daily temperatures are above 40 degrees. The air dewpoint temperature gives a good indication of whether air has much capacity to dry; a 20-degree difference between the air temperature and the air dewpoint temperature indicates good conditions for drying. See more details about natural air/low temperature bin drying at this website.
Do not warm grain that is already dry if you intend to keep storing it; instead, run aeration cycles in cool weather to maintain grain temperature below 40 degrees. The dewpoint temperature tells you about how cool grain will get during aeration. A large drying fan can cool a bin in about 15 hours, while an aeration fan will take close to a week to cool a bin. Estimate the time to cool a bin with your size fan in this recent blog post. If grain temperature is well below freezing, such as 20 degrees, gradually warming it to just above freezing may prevent excessive condensation and frozen chunks this spring or summer.
With the potential for poor quality grain in the bin, it is especially important to use good grain safety practices. Poor quality grain can cause problems such as surface crusting, hollow spots in the grain mass, grain that won’t flow when unloading, and sidewall buildup in the bin. Do not enter a bin if any of these occur, and instead attempt to work on the grain from above by poking and prodding it. If you have good quality grain and you must enter a bin, have an observer with you, use a life harness, and lockout/tagout grain equipment to keep it off.Category: Grain Handling and StorageTags: wet graindryinggrain storageAuthors: Kristina TeBockhorstShawn Shouse
Miscanthus research plots at Iowa State University's Sorenson Farm. Mature miscanthus is able to tolerate a flood better than corn and soy. Picture credit: Heaton Lab
The hypoxia zone in the Gulf of Mexico is a huge environmental issue, luckily there may be a solution to help reduce it. Vegetative and hydrologic modeling show that perennial grasses like miscanthus and switchgrass are better for water quality compared to annual crops.
Field trials at the University of Illinois at Urbana-Champaign concluded that miscanthus and switchgrass are more water-intensive than corn and soybeans. Along with using more water, perennials tend to have a longer growing season and provide more ground cover than annual crops. Based on this knowledge and modeling, it is assumed perennials could reduce nitrate levels in water, create less runoff, and reduce spring flooding in wetter climates compared to annuals systems.
Drainage pump for miscanthus plot at Iowa State UNiversity's Kitchen Farm. Picture credit: Heaton Lab
Iowa State University is currently conducting research to better understand how different cropping systems can alter the water cycle. Individual drainage has been set up under plots of miscanthus, biomass sorghum, corn, and soybeans with the goal of quantifying how much water and nitrate is flowing through each system.
Perennial crops offer many environmental benefits, and it appears that improving water quality could be added to the list. Be on the lookout for future blogs regarding miscanthus and an update on Iowa State’s findings regarding perennials and water quality! Also, be sure to check out ISUBiomass on Facebook, Twitter, and Instagram for more information regarding miscanthus.
Product of ISUBiomass Undergrad Team
 Vanloocke, Andy, Tracy E. Twine, Christopher J. Kucharik, and Carl J. Bernacchi. "Assessing the Potential to Decrease the Gulf of Mexico Hypoxic Zone with Midwest US Perennial Cellulosic Feedstock Production." GCB Bioenergy9, no. 5 (2016): 858-75. doi:10.1111/gcbb.12385.
 "The Pros and Cons of Miscanthus --uses More Water, Leaches Less Nitrogen." Department of Agricultural and Consumer Economics. September 9, 2010. Accessed December 17, 2018. https://ace.illinois.edu/news/pros-and-cons-miscanthus-uses-more-water-l....Category: Crop ProductionTags: miscanthuswater qualityAuthors: Tyler DonovanEmily HeatonCrop(s): Biomass and Forage
The Iowa State University on-farm cooperator demonstration trial program has a long-standing relationship with Iowa corn and soybean farmers. This program provides support and assistance to farmers interested in setting up strip trials to test new ideas on their farms. Local agricultural specialists, associated with ISU research farms, assist cooperators in the design, implementation and the analysis of the trial. The answers received from these trials allow farmers a firsthand look at products and practices so they can make better decisions on their operations. In 2019, 36 farmer-cooperators in 24 counties assisted in conducting 91 on-farm trials.
On-farm trials focus on agronomic practices and products, farm management studies and mechanical approaches to help producers improve their operations. These trials are conducted by farmer cooperators on their own farms or through ISU Research farms and associations. Test strips have varying sizes that meet individual farmers equipment and have at least three replications per treatment. The results from all ISU on-farm demonstration trials are reported every year in the ISU Research farm reports at the ISU digital repository. The trials can be found here https://www.iastatedigitalpress.com/farmreports/ and by searching each individual farm report.
An example of an ISU on-farm trials study from 2019 would be the application of the nutrient sulfur to both corn and soybeans. Sulfur deficiency has been showing up more frequently in Iowa corn fields in recent years. Studies have shown that yield responses are possible when fertilizing corn with sulfur. While deficiencies are more common in coarse or eroded soils, visual symptoms of sulfur deficiency can occur in all soil types. The objective of these trials was to evaluate potential yield response in corn and soybeans to sulfur applications. While only one trial in this study resulted in a significant yield response that we can be confident was related to the application of sulfur, results on your own farm may vary. Read more about Sulfur Management for Iowa Crop Production (CROP 3072).
Iowa State University and the on-farm trials program are committed to helping producers to improve their farms by providing unbiased information to help make decisions. Farmers conducting on-farm trials and sharing results from many sites within a region provides a better understanding of how management decisions interact with weather and soil variability. This understanding can help improve profitability for all farmers across the state. If you would like to learn more about ISU on-farm trials and on-farm trial results, or would like to create your own trial, please contact a member of the on-farm team listed below. You can also contact your local ISU field agronomist with questions about trials and information.
On-Farm Trials Team:
- Mike Witt, ISU Field Agronomist, On Farm Trials Coordinator, email@example.com, 641-430-2600
- Zack Koopman, Ag Engineering/Agronomy Farm, Ag Specialist Boone, IA firstname.lastname@example.org
- Lyle Rossiter, Allee Farm, superintendent, Newell, IA , email@example.com
- Jim Rogers, Armstrong Farm, Ag Specialist, Lewis, IA, firstname.lastname@example.org
- Brandon Zwiefel, Northern Farm, Ag Specialist, Kanawha, IA, email@example.com
- Shannon Hoyle, Northeast Farm, Ag Specialist, Nashua, IA, firstname.lastname@example.org
- Andrew Weaver, Northwest Farm, Ag Specialist, Sutherland, IA, email@example.com
- Chad Hesseltine, Southeast Farm, Ag Specialist, Crawfordsville, IA, firstname.lastname@example.org
- Craig Riesberg, Western Farm, Ag Specialist, Castana, IA email@example.com
Now is the time to be thinking about improving pasture stands by either the frost seeding method in February and early March or interseeding later in the spring months. Below are guidelines and considerations when it comes to frost seeding or interseeding.
Frost seeding involves spreading forage seed on existing pastures during the late winter or very early spring while the ground is still frozen. Freeze-thaw cycles then provide shallow coverage of the seed, which help shield the seeds from early spring rains. Frost seeding is the easiest method to add new forage legumes to pastures, and is likely the least expensive method, as well. To increase this method's success, spread seed on the thinnest pasture sod areas first and on areas where bare soil has been exposed due to heavy grazing or disturbance.
When it comes to frost seeding, don’t frost seed on top of a snow cover. The goal of frost seeding is to get seed on bare soil. If snow accumulates after you’ve frost seeded on bare ground, that is perfectly fine.
Red clover has been the Iowa forage species of choice for frost seeding. Other legumes, such as white clover and birdsfoot trefoil, also can be frost seeded but with less success than red clover. In general, frost seeding does not work as well with grasses.
A few well-researched steps will improve the success of frost seeding. Those steps, seeding rates and guidelines are available in the ISU Extension and Outreach publication Improving Pasture by Frost Seeding.
Interseeding offers an opportunity for improving pasture productivity too. Interseeding involves using a no-till drill to add additional forage species into an existing pasture stand. Interseeding is normally done from mid-March through early May when soil moisture and temperature are more suitable for rapid seedling establishment.
Interseeding can be accomplished with relatively few field operations. Opening of the grass sod, shallow seed placement, and seed coverage are required. While a number of drills are available for use in sod-seeding efforts, drills vary in their effectiveness based on ability to penetrate sod, provide uniform seed depth and metering, and the ability to cover the furrow. Equipment limitations for sod-seeding implements sometimes are overcome by operator experience and home shop modifications.
Figure 1. Interseeding in a pasture.
Clovers, alfalfa, and birdsfoot trefoil are legumes that have been successfully interseeded. Legumes interseeded into grass sod will help increase pasture yield, improve forage quality, and eliminate or minimize the need for nitrogen fertilizer. Perennial forage grasses can also be successfully established by interseeding. Thin, low-producing, grass sod might best be improved by interseeding a grass legume mixture.
A seeding delay into late spring to improve growing conditions often also leads to a greater competition from the existing grass sod. Close grazing in the fall or spring, ahead of interseeding, will help to reduce sod competition. Contact herbicides are sometimes also used to temporarily further reduce competition from plants present in the stand. Use only labeled herbicides for sod suppression and follow label instructions.
Interseeding success depends a lot on paying attention to details, timeliness, careful management of sod competition, controlling seeding depth to no deeper than one-fourth to one-half inch, and a little bit of luck with weather.
Interseeding research has been conducted in many parts of the U.S. and around the world. It shouldn't come as a surprise that the conclusions from these efforts all point to several very important issues that must be met for successful interseedings. See ISU Extension and Outreach publication Interseeding and No-Till Pasture Renovation for more suggested seeding rates and guidelines.
For more information, please contact your local Iowa State University Extension and Outreach field agronomist.Category: Crop ProductionTags: frost seedinginterseedingpasturesAuthors: Stephen K. BarnhartMeaghan AndersonRebecca VittetoeCrop(s): Biomass and Forage
CLARION, Iowa – A growing season outlook and a discussion on corn planting date research will highlight the annual meeting of the North Central Iowa Research Association March 4. The meeting will also feature an update of research at the Iowa State University Northern Research Farm at Kanawha.
This educational meeting will be held at The Red Shed Event Center, 908 Second Street NW, Clarion.
Registration and refreshments will begin at 9:30 a.m. and the meeting will start a 10 a.m. The meeting will adjourn at 1:30 p.m.
Speakers include board president Dennis Schwab, Matt Schnabel, Brandon Zwiefel, Mark Licht, Dennis Todey and Paul Kassel. Topics include planting date research, on-farm research, our changing growing season and an update on herbicide resistant traits in soybean.
There is no cost to attend. Participants are encouraged to pre-register by March 1 to help plan for meal numbers and handout materials. To register, call the ISU Extension and Outreach office in Wright County at 515-532-3453, or the ISU Extension and Outreach office in Hancock County at 641-923-2856.
Certified Crop Advisers can earn 3.5 CEUs (0.5 PM, 2.5 CM, 0.5 PD) for attending this meeting.
The North Central Iowa Research Association board of directors will meet at the conclusion of the annual meeting.Category: Crop ProductionTags: CornSoybeancrop productionAuthor: Paul KasselCrop(s): Corn
Iowa State University (ISU) Extension and Outreach will host two soil fertility workshops to help ag producers interpret soil test results and determine fertilizer needs and recommendations.
The first workshop will be held Wednesday, Feb. 26 at the ISU Extension and Outreach Sac County office location at 620 Park Street in Sac City. The same workshop will also be hosted the following day, Thursday, Feb. 27 at the ISU Extension and Outreach Clay County office located at 110 West Fourth Street in Spencer. Registration for both workshops will begin at 9:30 a.m. with the meeting held from 10:00 a.m. to 1:00 p.m. A light lunch will be provided.
"Producers are looking for ways to optimize crop yields and use their fertilizer dollars wisely" said Paul Kassel, field agronomist with ISU Extension and Outreach. “This workshop is designed to help farmers analyze their soil test results and determine how they can best supplement their soil’s fertility needs without breaking the bank.”
The workshops will help participants learn about soil testing procedures and applying those test results; calculating crop removal rates of phosphorus and potassium; reviewing crop yield responses to different soil test levels; and understanding return on fertilizer investments. There will also be a review of soil pH and ag lime usage, and a discussion about research on crop response to sulfur applications.
Certified Crop Advisor CEU credits will be offered. There will be two Nutrient Management credits and one Soil Water credit.
Kassel said that he will lead the workshops and be joined by Agronomist Mike Witt in Sac City.
To register for the Sac City workshop, call 712-662-7131. To register for the Spencer workshop, call 712-262-2264. Registration fee for both locations is $10 and will cover the training, resource materials and a light lunch.
Questions can be directed to Paul Kassel at 712-262-2264 or firstname.lastname@example.org.Category: Crop ProductionTags: fertilizer applicationfertilizer managementAuthor: Paul KasselCrop(s): Corn