Cover Crops for Better Corn and Soybeans

Our webinar on Wednesday featured Sarah Carlson, Strategic Initiatives Director at Practical Farmers of Iowa, who explained how cover crops and be a win-win for cash crops and the environment.

Cover crops can address water quality concerns, reduce soil erosion, and improve soil health. The figure above, from Carlson’s presentation, shows the effectiveness of cover crops at reducing nitrate in tile lines (10 mg/L is the drinking water standard). Despite these long term benefits, cover crops are not a widely used practice.

During the webinar, Carlson explained that low cover crop adoption may be linked to the amount of rented farmland in Iowa. Due to the nature of renting, renters need to see benefits to cover crops “tomorrow” rather than over the long term. Messaging about the benefits of cover crops that focuses on long term benefits will not increase adoption in areas where the majority of farmland is rented.

Carlson shared the highlights from several research projects that assess the more immediate benefits of cover crops. These short term benefits include reduced herbicide costs, weed control, as well as the effect of different cover crop termination dates ahead of soybean planting on yield. The results of these projects have indicated that cover crops can reduce herbicide costs (in some instances paying for themselves with the savings) and can offer weed control in the instance of herbicide-resistant plants.

To learn more about these research projects, their results, and the benefits of cover crops, watch the full webinar!

Join us on Wednesday, November 4 for a webinar with Adam Schnieders, water quality resource coordinator with the Iowa Department of Natural Resources, titled “Nutrient Reduction Progress at Iowa Wastewater Treatment Facilities.”

Hilary Pierce

Virtual Field Day November 5: Exploring Impacts of Cover Crops, Tillage & N-Inhibitors on Crop Performance and Water Quality

Iowa Learning Farms, in partnership with the Iowa Nutrient Research Center, and Conservation Learning Group (CLG), is hosting a free virtual field day exploring impacts of cover crops, tillage and nitrogen-inhibitors on crop performance and water quality on Thursday, November 5th at 1 p.m. CST. Join us for a live conversation with Matt Helmers, Director of the Iowa Nutrient Research Center, Emily Waring, Graduate Research Assistant, and Carl Pederson, Agricultural Specialist in Agricultural and Biosystems Engineering at Iowa State University.

Since 1989, research focused on the effects of nitrogen (N) management on crop production and tile drainage water quality has been conducted in north-central Iowa near Gilmore City. In 2010, the treatments were changed to examine the impacts of cereal rye winter cover crop vs. no rye (with and without tillage), conventional tillage vs. no-till, and timing of N-application and use of nitrification inhibitor. Through extensive data collection and monitoring, the team is measuring the impact of these practices on nitrogen and phosphorus loss and crop yield.

Matt Helmers and Emily Waring at the Gilmore City Research Plots

“This long-term dataset allows us to examine the impacts of conservation practices under a range of weather conditions. We have measured cover crops as an effective practice in reducing N loss from the cropping system,” says Helmers.

To participate in the live virtual field day at 1:00 pm CDT on November 5th, click HERE or visit www.iowalearningfarms.org/page/events and click “Join Live Virtual Field Day”. 

Or, join from a dial-in phone line:

    Dial: +1 312 626 6799 or +1 646 876 9923

    Meeting ID: 914 1198 4892

The field day will be recorded and archived on the ILF website so that it can be watched at any time. The archive will be available at https://www.iowalearningfarms.org/page/events.

Participants may be eligible for a Certified Crop Adviser board-approved continuing education unit (CEU). Information about how to apply to receive the credit (if approved) will be provided at the end of the live field day.

Liz Ripley

October 28 Webinar: Cover Crops for Better Corn and Soybeans

Integrating cover crops into corn and soybean cropping systems is the topic of the October 28 Iowa Learning Farms webinar.

Sarah Carlson, image courtesy of Practical Farmers of Iowa

Learn how cover crops can be a win-win for cash crops and the environment. During this webinar, Sarah Carlson, Strategic Initiatives Director at Practical Farmers of Iowa, will share research results about how cover crops can help farmers grow better corn and soybean crops, while also protecting water quality and improving soil health.

“Cover crops are not just good for water quality and soil health but should also be a part of the crop production decision-making discussion,” said Carlson, who will explain the economic benefits of using cover crops.

Carlson works to transfer agronomic research about cover crops and small grains through supply chain projects, articles, blogs and presentation materials, while working to improve the support for cover crop and small grain research.

Webinar Access Instructions

To participate in the live webinar, shortly before 12 pm CDT on October 28:

Click this URL, or type this web address into your internet browser: https://iastate.zoom.us/j/364284172

    Or, go to https://iastate.zoom.us/join and enter meeting ID: 364 284 172 

Or, join from a dial-in phone line:

    Dial: +1 312 626 6799 or +1 646 876 9923

    Meeting ID: 364 284 172

The webinar will also be recorded and archived on the ILF website, so that it can be watched at any time. Archived webinars are available at https://www.iowalearningfarms.org/page/webinars.

A Certified Crop Adviser board-approved continuing education unit (CEU) has been applied for, for those who are able to participate in the live webinar. Information about how to apply to receive the credit (if approved) will be provided at the end of the live webinar.

Hilary Pierce

Sustainable Weed Management Solutions for Iowa

This week’s Iowa Learning Farms webinar featured Prashant Jha, associate professor and extension weed specialist at ISU, sharing some of the unique research underway on sustainable weed management approaches for Iowa’s cropping systems.

Integrated Weed Management is a fascinating and ever-growing field, as farmers strive to efficiently manage weeds within their crop operations, in an environment where herbicide resistance has become ever-present and increasingly challenging.  For instance, Jha pointed out that three of Iowa’s most pervasive weed species—giant ragweed, marestail, and waterhemp—have all developed multiple resistances to different herbicides, posing major management challenges. At the same time, there do not appear to be major herbicide chemistry breakthroughs on the horizon.

Jha shared his group’s research findings on several different approaches to sustainable weed management, emphasizing that these are complimentary strategies, performing most effectively when in synergy with one another. Key sustainable weed management strategies highlighted in the webinar include:

Integration of Cover Crops
Jha’s team found cereal rye cover crops highly effective in providing weed suppression. For instance, one of the studies highlighted in the webinar yielded a 30% reduction in the amount (density) of waterhemp with the rye cover crop, and a 75% reduction in waterhemp growth (e.g. the weeds that did survive were much smaller) with the rye cover crop.

Reduction of Row Spacing
When comparing 15” vs. 30” row spacing in soybeans, the narrower row spacing resulted in substantially greater weed suppression, due to earlier canopy closure.

Equipment Modifications
Jha shared several equipment modifications and technologies currently being investigated for their ability to assist with weed suppression, including a chaff collection system to concentrate and capture the weed seeds at harvest …

… and a weed seed destruction unit, which directs the weed seeds through a high impact mill on the back of the combine, essentially crushing the weed seeds and leaving them non-viable.

Tune in to the full webinar to learn more about these different sustainable weed management solutions and the current research that’s underway!  You’ll find this and many other excellent webinars archived on the ILF webinars page.

Join us on Wednesday, October 28 for our next webinar, “Cover Crops for Better Corn and Soybeans,” with Sarah Carlson of Practical Farmers of Iowa.

Ann Staudt

Midwest Cover Crop Council Launches Updated Cover Crop Selector Tools

The Midwest Cover Crop Council (MCCC) Cover Crop Decision Tools are web-based systems to assist farmers in selecting cover crops to include in field crop and vegetable rotations.

The Cover Crop Decision Tools are an initiative by the MCCC to consolidate cover crop information by state to help farmers make cover crop selections at the county level. Information for each state/province is developed by a team of cover crop experts including university researchers, Extension educators, NRCS personnel, agriculture department personnel, crop advisors, seed suppliers and farmers. The team reviewed and refined information from the Sustainable Agriculture Research and Education (SARE)  publication Managing Cover Crops Profitably, 3rd edition to refine application within their state/province. The information and ratings contained in the Cover Crop Decision Tool is the team consensus based on literature, research results, on-farm experience and practical knowledge.

Decision Tool Q&A Webinar

Wednesday, September 23rd at Noon Eastern / 11:00 am Central

Join MCCC for an in-depth look at the revised decision tool with Babak Saravi, Ian Kropp with the Decision Support and Informatics Lab of Michigan State University and Dean Baas and Anna Morrow with the Midwest Cover Crops Council.

This webinar will be recorded and posted here for later viewing.

Register Here

Liz Ripley

Long-Term Impacts of 4R Nitrogen Management Practices and Cover Crops on Nitrate-N Loss

Iowa Learning Farms hosted a webinar on Wednesday about the impacts of nitrogen management practices and cover crops on downstream nitrate-N loss. Matt Helmers, Director of the Iowa Nutrient Research Center, explained long-term research that monitors drainage water quality at five sites throughout Iowa. The 4Rs of nitrogen management discussed during the webinar are right source, right rate, right time, and right place.

Corn yield at one of the research sites, comparing fall, spring, split, and no nitration application over five years (image from Helmers’ presentation)

Helmers shared results of the corn yield comparing fall, spring, split, and no nitrogen application over five years at one of the study sites. There was no statistical difference between the yields when nitrogen was applied (with lower yields when there was no nitrogen applied). Applying nitrogen closer to when crops take it up has the potential to reduce nitrogen loss. Flow-weighted nitrate-N concentrations for the corn and soybean phases over 2015-2018 are shown below.

Timing of swine manure application and use of a cover crop was studied at another one of the research sites. Increased loss of nitrate-N when injecting manure soon after soybean harvest was seen, but this loss could be mitigated by using a cover crop. There was a benefit to late fall manure application to both nitrate-N loss and corn yield seen as well.

Flow-weighted nitrate-N concentration comparing swine manure application timing and cover crop use, 2016-2019 (image from Helmers’ presentation)

Helmers shared a 10-year summary of nitrate-N loss that compared continuous corn, continuous corn with a cover crop, prairie and fertilized prairie. He also discussed the impacts of dry conditions on nitrate-N loss, showing data from 2013, the year after the drought of 2012, which saw an increase in nitrate-N loss. Cover crops were shown to reduce the nitrate-N loss and could be effectively used following dry periods.

To learn more about this research, watch the full webinar here!

Join us next week for a webinar with Billy Beck titled “Lessons From the Derecho: Addressing Storm Damage and Working Towards Resilient Forest and Tree Resources”. Beck is the Extension Forestry Specialist and Assistant Professor in the Department of Natural Resource Ecology and Management at Iowa State University

Hilary Pierce

September 10 Virtual Field Day: Redefining the Field Edge

Iowa Learning Farms, in partnership with the Iowa Nutrient Research Center, and Conservation Learning Group (CLG), is hosting a free virtual field day focused on redefining the field edge with the use of perennial vegetation on Thursday, September 10th at 1 p.m. CDT. Join us for a live conversation with Floyd County farmer Dennis Staudt and Mark Licht, Iowa State University Assistant Professor and Extension Cropping Systems Specialist.

Patty and Dennis Staudt on their Century Farm in Floyd County

The prairie pothole region runs from central Iowa north and west into Minnesota, South Dakota, North Dakota, and across the plains of Canada, covering nearly 173 million total acres. Even with subsurface drainage systems in place, many of these small prairie potholes are associated with high production risk and often represent the lowest profitability areas within a field. A CLG project led by Licht and funded by North Central Region Sustainable Agriculture Research and Education is working with Staudt and three additional Iowa farmers to convert marginal land areas to perennial vegetation to evaluate the return on investment and explore the potential benefits to water quality, soil health and wildlife habitat.

“The edge of the field that was seeded to perennial vegetation this spring and borders on a creek that runs from a drainage district and passes it downstream. The creek is in the ditch, however, in rainy seasons, it fills up the creek and actually goes over the road in places, and likewise comes into my field. On average, I was able to harvest a profitable crop one out of three years,” noted Staudt. “I am hopeful this project will result in less grief in maintaining and harvesting that area while conserving the soil.”

To participate in the live virtual field day at 1:00 pm CDT on September 10th, click HERE or visit www.iowalearningfarms.org/page/events and click “Join Live Virtual Field Day”.

Or, join from a dial-in phone line:

    Dial: +1 312 626 6799 or +1 646 876 9923

    Meeting ID: 914 1198 4892

The field day will be recorded and archived on the ILF website so that it can be watched at any time. The archive will be available at https://www.iowalearningfarms.org/page/events.

Participants may be eligible for a Certified Crop Adviser board-approved continuing education unit (CEU). Information about how to apply to receive the credit (if approved) will be provided at the end of the live field day.

Liz Ripley

September 2 Webinar: Long-Term Impacts of 4R Nitrogen Management Practices and Cover Crops on Nitrate-N Loss

Iowa Learning Farms will host a webinar on Wednesday, September 2 at noon about the impacts of nitrogen management practices and cover crops on downstream nitrate-N loss.  

The 4Rs of nitrogen management are right source, right rate, right time, and right place. Right source refers to using the correct fertilizer for the soil and crop needs, right rate means that the application rate matches the crop requirements, right time means ensuring that nitrogen is available when the crop needs it, and right place refers to placing and keeping nitrogen where the crop can get to it. Matt Helmers, Director of the Iowa Nutrient Research Center, will explain the long-term impacts of using nitrogen management practices, as well as the use of cover crops, on nitrate-N loss from agricultural systems.

Applying nitrogen closer to when crops take it up has the potential to reduce nitrogen loss. Future nitrogen management will need to take the dry conditions of summer 2020 into consideration and cover crops may be an important tool for reducing risk of increased nitrogen loss during subsequent wet periods.

“Agricultural producers are increasingly challenged to reduce downstream nitrate-N loss. The first step in reducing nitrogen loss is good in-field nitrogen management,” said Helmers, a research and extension agricultural engineer who focuses on agricultural water quality, specifically nitrate-N loss through drainage systems.

To participate in the live webinar, shortly before 12:00 pm CDT on September 2:

Click this URL, or type this web address into your internet browser: https://iastate.zoom.us/j/364284172

    Or, go to https://iastate.zoom.us/join and enter meeting ID: 364 284 172 

Or, join from a dial-in phone line:

    Dial: +1 312 626 6799 or +1 646 876 9923

    Meeting ID: 364 284 172

The webinar will also be recorded and archived on the ILF website, so that it can be watched at any time. Archived webinars are available at https://www.iowalearningfarms.org/page/webinars.

A Certified Crop Adviser board-approved continuing education unit (CEU) has been approved, for those who are able to participate in the live webinar. Information about how to apply to receive the credit will be provided at the end of the live webinar.

Hilary Pierce

Cover Crop Options to Consider for Damaged Crops this Fall

This article was originally published on August 27, 2020 by Mike Henderson and Mark Licht for Integrated Crop Management News and Iowa State University Extension and Outreach.

Many fields have been ravaged by adverse weather this year in Iowa. On top of drought and hail we had a devastating derecho steam-roll a wide swath of Iowa starting in Sac County and progressing eastward along Highway 30. Along with the decision of how to handle this year’s crop, consideration for protecting the soil and preparing for next year’s crop should include cover crops.

Use of cover crops after a crop is damaged by adverse weather can provide short term protection of the soil while enhancing the long-term benefits of increased water infiltration, improved nutrient cycling and soil organism diversity. Using a cover crop to scavenge nitrogen will be especially important in areas of Iowa that experienced reduced yields due to drought conditions. Cover crops have shown a significant reduction in nitrogen loss from fields the year following a drought.

Successful cover crop establishment will require managing the damaged crop residue to allow seed-to-soil contact and also considering the likelihood of sufficient soil moisture for cover crop establishment.

Cover crops and moisture concerns

Cover crops need moisture to germinate, soil to root in and sunlight to grow. Timing and method of cover crop seeding will be critical this year for successful cover crop establishment, especially given the expanding drought. Moisture is always a consideration for timing of seeding, this will be no different this year for all parts of the state. The decision on method of seeding; aerial, broadcast, broadcast/incorporate or drill, will be more important than ever this year.

Moisture concerns are not only to get the cover crop established but also for next year’s crop. It has been proven that good cover crop growth will increase infiltration rate, allowing more rainwater to be captured by the soil during rain events. Terminating the cover crop earlier in the spring will conserve accumulated moisture if rain shortfalls continue through spring.

Cover crops and damaged crops

Best management practices for wind damaged corn should be based on severity of the damage and how, or if, the crop will be harvested. Fields flattened by wind or with a high degree of green snap will have varying degrees of dense leaf cover. Evaluate fields prior to aerial seeding for confidence in getting the seed in contact with soil. In most cases aerial application over these fields would be an acceptable method but considerations must account for planned method and timing of harvest.

For fields that will be unharvested and tillage will be used to size residue, seeding a cover crop after the tillage operation will provide soil cover and protection. Timing of planting will dictate what cover crop species are best suited to be planted. If the tillage is done prior to mid-September, a mix of non-winter hardy species will provide fall protection and will not need to be terminated in the spring. Winter hardy species are a great option anytime in the fall and will extend benefits of living roots and soil cover into the spring. Seeding dates vary across the state based on historical frost dates but anytime seeding is past mid-September, a winter hardy species is recommended.

For fields planned to be harvested for silage or baled, seeding the cover crop immediately after harvest will provide the best establishment window.

Harvesting downed corn pushes the limitations of both equipment and operator. Seeding a cover crop too early could provide enough cover crop growth to further visually impede harvest. Seeding after the crop is harvested with a drill to get good seed-to-soil contact will increase chances for successful establishment of the cover crop. Consider how the crop will be harvested along with severity of damage when deciding what cover crop species, method and timing of seeding will be used.

Seeding options

Aerial/broadcast application should be timed 10 to 14 days prior to the canopy opening up. This is when soybeans have 10-20% of the leaves in the upper canopy turning yellow. For corn planned for grain harvest, this will be when kernels are at half milk line (mid R5). Increased success with establishment will occur if moisture is received within 10 days of the aerial application. Use of aerial application on damaged corn needs to take into account planned harvest method and current level of soil exposed.

Drilling or broadcast with incorporation always provides the most consistent cover crop stand. A drawback to this method is the shortened time for fall growth of the cover crop but using a winter hardy cover crop like cereal rye or triticale are good options to consider. Physical disturbance of corn ears on the ground will promote germination of volunteer corn.

Management of fields with downed corn will be a challenge, but it does not eliminate the opportunity to seed cover crops yet this fall.

August 26 Webinar: Evaluating Annual Forages for Beef Cattle: ISU Forage Research Test Plots

Iowa Learning Farms will host a webinar on Wednesday, August 26 at noon about a current research project that assesses forage quality and potential yield of various annual crops.

Incorporating annual forages into Iowa’s cropping system provides flexibility for land use, alternative forage availability at times of limited perennial forage for cattle, as well as other conservation practices. In an effort to benchmark utilization of winter and summer annuals as a forage resource for beef cattle, forage test plots at three outlying Iowa State University Research Farms have been established to evaluate nutrient quality and potential yield.

Erika Lundy, Extension Beef Specialist at Iowa State University Extension and Outreach, will share the current results of this research project, which aims to provide research-based information that will help establish reasonable expectations in terms of forage quality and yield of various cover crop and summer annuals.

“In addition to the alternative forage resource annuals bring to farming enterprises, forages are valuable additions for preserving Iowa farmland’s soil and water quality,” said Lundy, whose current extension and research programs are focused on beef cattle nutrition and forage management to improve profitability on the farm level.

To participate in the live webinar, shortly before 12:00 pm CDT on August 26:

Click this URL, or type this web address into your internet browser: https://iastate.zoom.us/j/364284172

    Or, go to https://iastate.zoom.us/join and enter meeting ID: 364 284 172 

Or, join from a dial-in phone line:

    Dial: +1 312 626 6799 or +1 646 876 9923

    Meeting ID: 364 284 172

The webinar will also be recorded and archived on the ILF website, so that it can be watched at any time. Archived webinars are available at https://www.iowalearningfarms.org/page/webinars.

A Certified Crop Adviser board-approved continuing education unit (CEU) has been approved, for those who are able to participate in the live webinar. Information about how to apply to receive the credit will be provided at the end of the live webinar.

Hilary Pierce