By Ronica Stromberg
Lord Ameyaw recently received a $682,335 Conservation Innovation Grant to study and test alley cropping, a farming method including rows of trees in agricultural fields.
The forester and assistant professor in the School of Natural Resources said his project includes comparing various designs of alley cropping and the benefits of each. He and Ann Powers, a forestry lecturer and co-investigator, plan to test alley-cropped fields for drought and wildfire resilience and look at policy and tax incentives that either promote or deter its use.
“The project is ambitious,” Ameyaw said. “That’s what we all thought when we were putting it together. It’s huge.”
The grant is the first major one he has secured and is the first grant Powers has been on. The two run the Regional and Community Forestry program at the University of Nebraska-Lincoln and will carry out the three-year project at the Horning State Farm near Plattsmouth.
The farm has had a 14-acre demonstration site for alley cropping since about 2006. At the site, Chinese chestnut, northern pecan and black walnut trees are planted in rows with about 20 feet between trees in each row. The distance between one row of nut trees to the next row of nut trees is about 40 feet planted with tall grass.
“The idea is that your introducing the trees in those rows creates this kind of microclimate for the understory or the project crops to thrive whilst you're having the tree crop also at the same time,” Ameyaw said. “So, it's some income diversification for the producer or the farmer or the landowner.”
The forester said he will be comparing the 20- and 40-foot layout of the alley-cropped field with other possible layouts to recommend distancing for farmers.
“I've not seen the research that says ‘This is best’ or ‘That is best’ because it varies depending on what trees are in there and what agriculture crops you have,” he said. “So, there's no really standardized number for spacing your trees and crops, but we want to come up with some kind of a sweet spot for any farmer or producer out there.”
Regular crops like corn can be planted between the tree rows in alley cropping, but Ameyaw said some configurations, like pecans and apples, do not work well together. He and Powers lack time in the three-year project to plant and grow fruit trees to test. They will, instead, identify and interview farmers using tree-and-crop combinations to weigh costs and benefits.
Ameyaw has already reached out to Mayan farmers in Omaha who have used alley cropping in some form for a long time. He said a benefit of working with the Mayans is their understanding of how to move the alley cropping system from the tropical climate they formerly worked in to the temperate climate of Nebraska. In return, Ameyaw and Powers plan to share project results with the Mayans to further aid them in alley cropping in Nebraska.
Powers said alley cropping has never been practiced much in Nebraska, probably because people are used to modern agriculture and seeing fields growing only one crop and at an even height.
“That's what people want to see now in Nebraska,” she said. “We just don't have as many trees that would have been duly productive. So, in our alley cropping system, we can have trees that are productive as well as a crop underneath them that is productive. In Nebraska, besides black walnut, we didn't have a lot of native species that were productive outside of shade.”
She said that without a clear profit, farmers may not have looked further at alley cropping but Nebraska can grow pecans and fruits like apples, persimmons, grapes, serviceberries, pears and peaches, although some of these plants produce better in other climates.
Ameyaw pointed out that another reason for the seeming lack of interest in alley cropping is that few demonstration sites exist for farmers to see how it’s done or gain familiarity with it.
Across the United States, alley cropping has not caught on, with sources like the USDA placing estimates of farms using agroforestry at less than 2%. Alley cropping is just one of five agroforestry practices, and the least popular in the United States, Ameyaw said.
Still, USDA conservation programs and scientific literature have promoted alley cropping as helping to control erosion, sequester carbon and better withstand drought. Ameyaw and Powers will test alley cropping’s resilience to drought by simulating drought conditions in the Horning field. They will measure sap flow and install dendrometers to collect data like plant growth.
They also stated plans to use a software application to simulate wildfire and test the potential that alley cropping holds to reduce wildfires and their impacts.
They plan to investigate what policy and tax incentives exist that either favor or disfavor agroforestry and alley cropping specifically in the Midwest. Ameyaw said they will hire a graduate student to work on that.
They plan to disseminate their findings through outreach, workshops, storytelling, extension, and peer-reviewed publications.
“We are scientists, so we are really interested in publishing our data and some of our results, but I really want us to design things that are really friendly for producers, not very lengthy, lots of photos, just to show what we're doing,” Ameyaw said.
His first step on the grant, he said, will be to meet with contacts from the Nebraska Forest Service, which controls the Horning farm, and the National Agroforestry Center. He plans to scope out the farm with them in October to discuss the experimental setup and capture drone footage of the project site.
Both he and Powers said the Horning State Farm appears to have been underused for research for the past several years and they look forward to researching alley cropping there. Although Powers has found research about alley cropping in the Midwest, she said she has been unable to find any alley cropping research in Nebraska from the past 20 years.
Andrew Zahn, who supervises operations at the Horning State Farm for the Nebraska Forest Service, expressed interest in Ameyaw’s research, especially alley cropping’s role in drought tolerance and wildfire risk mitigation. He said he would be very interested in watching and helping with the project.
“I personally wish that alley cropping as a practice was more common in Nebraska and even in this country,” Zahn said. “If it were, I think it would mimic an earlier time in this country’s agricultural history when farmland fields were smaller, protected by shelterbelts, and were part of a patchwork mosaic that benefited people and wildlife alike.”