Optimizing Manure Application to Minimize Nutrient Loss and Maximize Benefit

Please join us for the Iowa Learning Farms webinar at noon, Wednesday, August 4, featuring Melissa Wilson, assistant professor and extension specialist, University of Minnesota.

In her session, “Applying Liquid Manure to Living Roots: Research Update,” Wilson will provide an update on best practices for manure application and the results from the past several years’ research. The webinar will include observations and outcomes of research regarding the optimization of manure application to minimize nutrient loss while maximizing the availability of nutrients from this home-grown resource to crops.

“Optimizing the use of this renewable resource can help reduce fertilizer needs (saving money!),” said Wilson. “Developing and refining best practices for manure application will deliver substantial benefits to farmers while minimizing nutrient losses from fields.”

Participants in Iowa Learning Farms Conservation Webinars are encouraged to ask questions of the presenters. People from all backgrounds and areas of interest are encouraged to join.

Webinar Access Instructions

To participate in the live webinar, shortly before noon CDT August 4:

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. Those who participate in the live webinar are eligible. Information about how to apply to receive the credit will be provided at the end of the live webinar.

Cover Crop Impacts on Crop Yield and Water Quality

Harvest 2020 marked the seventh and final year of our cover crop mixtures trial at ISU research farms. First established at six ISU Research and Demonstration farms in the fall of 2013, our team set out to determine the impact of cover crop mixtures on management, soil health and water quality. In fall 2016, the project continued at four sites and three sites were seeded for the seventh year in 2019.

The plots compare three treatments–single species, mixture, and no cover crop. Each treatment is replicated four times at each site in both corn and soybean, for a total of 24 plots at each farm. The plots range from 6 to 12 rows wide and all are 50 feet in length.

For all sites and all years, spring and fall cover crop biomass, and cash crop yield data were collected to evaluate the establishment of the cover crops and potential yield impacts. Late spring nitrate was collected at all sites from 2015 to 2017. At five of the sites, water quality samples were collected using suction lysimeters.

Biomass Results

The above ground biomass samples were sorted by species to determine the establishment success and growth. The sites on the left are north of Hwy 20 and the sites on the left are south of Interstate 80. Across treatments and sites, the grass species (cereal rye and oats) dominated. The radish performed better in the southern locations compared to the northern sites.

Biomass is one of the main ways cover crop success is measured as it is directly tied to erosion reduction, nutrient uptake and potential weed suppression. The results from this study indicate that cereal rye and oats are the best suited species to Iowa’s dominate rotation of corn and soybeans. They are also significantly less expensive on their own compared to the mixtures used:

Average seed cost/acre for the 2017-2019:

Rye: $18.78  vs  Rye, Rapeseed, Radish Mix: $30.46

Oats: $17.44  vs  Oats, Hairy Vetch, Radish: $63.29

Water Quality Results

Pore water suction lysimeters (picture below) were installed at a 24 inch depth to collect water samples in the crop root zone to determine nitrate concentrations under each treatment. These were installed at 5 sites and provided 17 site years of data. Samples were collected every two weeks between April and November.

Compared to the no cover treatments, all four cover crop treatments reduced nitrate concentration and prevented that nitrate from leaving the system.

Yield Results

There was no statistical yield difference in the corn and soybeans between the treatments. This indicates that properly managed cover crops do not negatively impact crop yields.

Overall Conclusion

• Rye and oats provide the best biomass return on seed investment! Single species are the way to go in Iowa.
• Corn and soybean yields were unaffected by the presence of a cover crop.
• Adjusting planter settings to manage additional residue will minimize yield risk.
• Nitrate concentrations in pore water were significantly reduced with cover crops.
• Rye and oats provide the best reduction in nitrate concentration, improving water quality.

To learn more about this project, be sure to watch our May 2019 webinar featuring Emily Waring and read the final research farm report now available online. Emily is utilizing this project as part of her PhD dissertation and has provided great assistance in the continuation of the project and data analysis.

Liz Ripley

Spotlight on Kernza

What the heck is Kernza?!  Tune in to our most recent Iowa Learning Farms webinar, featuring the University of Minnesota’s Manbir Kaur Rakkar, to explore this new niche grain crop and its potential benefits to agricultural cropping systems in the Midwest!

Kernza, also known as intermediate wheatgrass, is a cousin of annual wheat. Bred by The Land Institute and University of Minnesota, Kernza is a particularly unique addition to Midwest cropping systems in that it is a perennial with deep, dense root systems, with uses both for forage and as a grain crop.  It is a relative newcomer to the scene, with its breeding program initiated in 2003.

Being a perennial offers some definite benefits: year-round root coverage, decreased erosion, and increased infiltration. But what measurable impacts does Kernza have on soil health? And is it an agronomically-feasible crop to integrate into Midwest cropping systems? 

In this recent ILF webinar, Improving Soil Health with a Novel Perennial Grain Crop, Rakkar shares active research that is underway in Minnesota investigating this emerging crop. With her research focused on soil health, Rakkar shares results on Kernza’s performance in a variety of different soil health parameters, and its impacts on subsequent corn/soybean crops (SPOILER ALERT: No negative yield effects on subsequent corn/soybean crops, and lower weed pressure following Kernza!).

To learn more about this unique crop and the active research that’s underway, watch the full archived webinar on the ILF Webinars page. Also, be sure to check out Kernza.org for more information about Kernza’s uses and the emerging markets surrounding it.

Finally, a quick programming note:
ILF will NOT have a webinar this next week on Wednesday, July 28, as our team will be presenting at the Soil & Water Conservation Society Annual Conference. Weekly webinars will resume on Wednesday, August 4 at noon, featuring Melissa Wilson, University of Minnesota, sharing perspectives on optimizing manure nutrients for crop production.

Ann Staudt

Let’s Chat Cover Crops

Did you know there are over 50 episodes of the Conservation Chat available that explore many different voices of conservation and quite a few discuss the role cover crops play in improving soil health and water quality?

I encourage you to check them all out, but wanted to highlight a more recent episode with Wade Dooley and Nathan Anderson. Both a young farmers working to increase the resiliency of their farms using a combination of conservation practices, like cover crops, and livestock.

It is clear that both are passionate about their land and their farming practices. In the chat with host Jacqueline Comito, Anderson discuses the mission and vision statements that he and his wife have been working on for their farm. Dooley also shares the big changes he started in 2020: moving away from row crops to CRP acres and a grass-fed cow-calf operation. Both men stressed the importance of finding a system that allows you to do what you enjoy, but also be a successful and profitable business.

Dooley and Anderson are truly “farming for the future”. While different approaches, both are working on making their farms resilient to the changing climate and finding systems that allow them to learn, adapt and get excited to try again next year. To learn more about the challenges and opportunities that they see on their farms and for rural Iowa, listen to the podcast here or on iTunes!

Liz Ripley

A Novel Grain that Improves Soil Health and Produces a Viable Crop

Please join us for the Iowa Learning Farms webinar at noon, Wednesday, July 21, featuring Manbir Kaur Rakkar, postdoctoral associate at the University of Minnesota – Twin Cities. Rakkar will share the results of her research in interdisciplinary approaches to improving soil health. In her session, “Improving Soil Health with a Novel Perennial Grain Crop,” Rakkar will highlight research with Kernza®, and its potential to improve soil health while producing a useable grain crop.

“Novel perennial grains such as Kernza can be viable agronomic solutions that mitigate soil health and environmental problems, particularly during an organic transition period,” said Rakkar. “It is important to look at alternative methods that may be adopted to reverse ongoing soil and environmental degradation.”

Participants in Iowa Learning Farms Conservation Webinars are encouraged to ask questions of the presenters. People from all backgrounds and areas of interest are encouraged to join.

Webinar Access Instructions

To participate in the live webinar, shortly before noon CDT July 21:

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.

Igniting a Spark

Today’s guest blog post comes from water resources intern Celaysa Mora.  Originally from Des Moines, IA, Mora is a rising senior at Iowa State University, majoring in forestry with an emphasis in natural resources interpretation.

Sometimes as a student we don’t quite know what we want to do with our career. We come from different backgrounds allowing us different experiences that shape our interests and values. All of that will play into what path we take with our lives. I am grateful to have been given opportunities to experience different paths. Having worked a plethora of jobs from being a CNA to working at an aquarium, none have resonated with me quite as much as being an intern with Water Rocks! and Iowa Learning Farms.

Water Rocks! and Iowa Learning Farms have helped me grow as an educator, conservationist and student in the span of a summer. Everything I had been learning in my classes came full circle. I took a policy class prior to beginning this internship. After the class I thought I made a mistake in the career path I was taking. Policy shapes how our land is treated and it seemed nothing effective was being done. While I can’t quite tell people policies to advocate for, I can give them background on the issues. Igniting a spark about conservation in Iowa is a blessing, whether it be at a school, town festival or county fair.

A few weeks ago we visited a summer program with the Oakridge Community in Des Moines. We talked to students from Kindergarten through 8th grade and it reminded me of why I chose to be a part of outreach. They were so eager to learn and made me think of my own enthusiasm.

Being outside has always felt instinctive and influenced my decision in choosing my major. In my forestry major, I have chosen my focus to be on interpretation, meaning I want to take technical information and make it palatable for the public. I enjoy talking to people of all backgrounds, so creating a dialogue about conservation with people who may or may not care is something I find worthwhile. Before this internship, I was worried if outreach is something I would enjoy or even be good at. I am thankful that outreach is an adventure I enjoy and I continue to improve each time I present.

While the idea of graduating is scary and full of uncertainty, I am certain that teaching the public about conservation is something I enjoy and want to spend my time doing. I am so thankful to all aspects of this internship. Being a part of the Water Rocks! and Iowa Learning Farms team has pushed me to learn about conservation through narratives other than my own.

Celaysa Mora

Are Stream Channel Sediment and Nutrient Sources Masking Upland Conservation Progress? – Webinar Recap

In this week’s webinar, “Are Stream Channel Sediment and Nutrient Sources Masking Upland Conservation Progress?,” Billy Beck discussed a recent study of in-channel sediment contributions to phosphorus levels in water. Noting that there is a growing body of evidence suggesting the stream channel itself may act as a significant source of sediment and nutrients such as phosphorus, Beck has been working to quantify the sources of sediment and phosphorus at the watershed scale.

Billy Beck is an assistant professor and extension forestry specialist at Iowa State University.

“Water quality management takes more than in-field and edge-of-field practices – we need to start addressing the stream channel itself.”

Billy Beck

Be sure to check out the archive of this webinar to hear more of his discussion. You can catch up on all our previous webinars any time by visiting the ILF website.

Tune in to our next webinar on Wednesday, July 21st at noon for Improving Soil Health with a Novel Perennial Grain Crop, featuring Manbir Kaur Rakkar, Post-Doctoral Associate, Dept. of Agronomy and Plant Genetics, University of Minnesota.

Nathan Stevenson

Cover Crop Species Selection Made Simple

The Whole Farm Conservation Best Practices Manual provides four easy to follow decision trees for selecting the cover crop species and seeding method this fall to fit your operation.

Designed to help those getting started with cover crops be successful, the decision trees and management recommendations are based on years of research and demonstrations by Iowa State University, Iowa Learning Farms, Practical Farmers of Iowa, Iowa Soybean Association, Iowa USDA-Natural Resources Conservation Service and the USDA-Agriculture Research Service.

6 Tips to Success for Starting Out with Cover Crops:

  • Oats ahead of corn
  • Cereal rye ahead of soybean
  • Selecting the seeding method that fits your system (see decision trees below)
  • Terminate 10-14 days ahead of corn and 3-7 days ahead of soybeans
  • Spring tillage of cover crops is NOT recommended
  • Adjust planter settings to higher residue system

The manual provides more detailed information on each of these tips and more, so download a FREE copy for your farm today.

Also be sure to check out our YouTube video series Cover Crops: Farmer Perspectives and Adding a Cover Crop to a Corn-Soybean System.

Liz Ripley

Time to start thinking about overseeding cover crops

In the last decade, cover crops have grown in both interest and acres, yet there is still room for more adoption across Iowa and the region. It is obvious that cover crops require more management though and with that management there will undoubtedly be challenges. In just a few weeks the cycle for cover crop establishment, growth and termination will begin.

Seeding method, time and species all interact with each other, and each decision affects the other. Most Iowans who participate in cover crops are using winter (cereal) rye or oats when overseeding into their standing crop by broadcast with high clearance equipment, or airplane. This is different than interseeding into the standing crop at early vegetative stages. Overseeding into crops nearing maturity is much more reliable than interseeding into vegetative stage crops. Yet there are challenges associated with overseeding.

Timing is everything. Too early and corn and soybean crops shade too much. Rainfall patterns and soil moisture are also critical, as if it is too dry, broadcast seeds will not germinate sitting on the dry soil surface. Overseeding also does not provide uniformity or seed to soil contact that is gained from drill seeding after harvest.

Mid-April cover crop growth, overseeded into standing corn the previous fall

There are definite benefits to overseeding though. The time overseeding occurs is when labor needs are not as demanding, which is usually the last week of August through that first week of September. This assumes there is rainfall in the forecast or ample soil moisture. But is critical to be flexible, and remember that crop development is strongly influenced by weather conditions. If growing degree days conditions continue to accumulate rapidly, the timeframe could be earlier than the end of August. When corn leaves are firing up to the ear leaf or the soybean canopy is starting to yellow is a good indication of when to overseed. Timely rainfall is critical for cover crop germination, so be flexible if conditions are dry and rainfall is not in the forecast. September brings increased rain probabilities, which may lead to more successful cover crop establishment. While larger seeded species such as cereal grains require more moisture for germination, once they have enough moisture, they can establish well in a broadcast situation.

When seeding at an earlier time, overseeded cover crops tend to have more biomass growth in the fall. This is a key to reducing nutrient losses by either leaching or erosion, and if grazing is desired, more biomass results in fewer days of fed hay and grains. This is a drawback to drill seeding, as harvest could delay seeding, which can reduce biomass growth and nitrogen uptake. 

Mid-April cover crop growth, overseeded into standing soybeans the previous fall

When considering seeding rates, it is important to assess soil and weather conditions. Typically, overseeding requires a higher seeding rate – 60 to 70 pounds per acre – than if drill seeding following crop harvest. This higher seeding rate is warranted because lower germination rates associated with dry soil surface conditions, minimal seed-to-soil contact, seed scavenging by bird and rodents, and poor light intensify from crop canopy and residue. An additional seeding rate adjustment should be made based on the percent pure live seed (PLS). Low PLS percentages should dictate a higher seeding rate.

More information on cover crop establishment considerations can be found in the Whole Farm Conservation Best Practices Manual, available for free download from the ISU Extension Store.

Mark Licht

Does Stream Channel Sediment Obscure Conservation Efforts?

Please join us for the Iowa Learning Farms webinar at noon, Wednesday, July 14, featuring Billy Beck, assistant professor and extension forestry specialist, Iowa State University. Beck will highlight recent research on water quality related to quantifying the contributions to phosphorous and sediment in waterways at a watershed scale, in his session, “Are Stream Channel Sediment and Nutrient Sources Masking Upland Conservation Progress?.

Beck’s research focuses on the impacts that trees, forests, and forestry have on water quality and hydrology within agriculturally-dominated Midwestern watersheds, and will draw on his expertise to discuss ways in which nutrients and sediment from stream channels may be obscuring progress made through in-field and edge-of-field conservation practices.

“Water quality management takes more than in-field and edge-of-field practices – we need to start addressing the stream channel itself,” said Beck. “The stream channel plays a significant role in sediment and nutrient loading, but inflow to the stream and remobilization do not occur in a highly-predictable timeframe. Managing nutrient sources in uplands and riparian areas is very important but looking more closely at the stream channel will help us obtain a more comprehensive understanding of nutrient and sediment sources and impacts to water quality.”

Participants in Iowa Learning Farms Conservation Webinars are encouraged to ask questions of the presenters. People from all backgrounds and areas of interest are encouraged to join.

Webinar Access Instructions

To participate in the live webinar, shortly before noon CDT July 14:

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.