Farmlands can be redesigned to suppress the pests that threaten the crops that feed the world, according to the keynote speaker at the 2022 AAAS Charles Valentine Riley Memorial Lecture.
Douglas Landis, University Distinguished Professor of Entomology at Michigan State University, spoke about “Designing Pest Suppressive Agricultural Landscapes for a Changing World” as part of the Riley Lecture, now in its 12th year. The lecture, a collaboration between AAAS, Charles Valentine Riley Memorial Foundation and World Food Prize Foundation, aims to promote a broader and more complete understanding of agriculture as the most basic human endeavor and to enhance agriculture through increased scientific knowledge.
Landis’ Nov. 30 address was followed by a wide-ranging conversation with expert panelists Dr. Fred Gould, William Neal Reynolds professor of agriculture, North Carolina State University; Dr. Steven Bradbury, professor in the Departments of Natural Resource Ecology Management and Entomology, Iowa State University; Dr. Megan Fritz, assistant professor in the Department of Entomology and Institute for Advanced Computer Studies, University of Maryland; and Dr. Linda Kinkel, professor of plant pathology, University of Minnesota about agricultural pest management, touching upon genomic variation in pest suppressors to soil microbiomes to the practical realities of implementing pest-suppression strategies.
Undertaking agricultural pest management through landscape redesign offers challenges and opportunities, Landis noted. To succeed, teams must draw upon scientific evidence, recognize that every landscape and every situation has different needs and commit to working closely with farmers and other stakeholders, he said.
The event is named for Charles Valentine Riley, a 19th century entomologist who sought to advance our understanding of “the broad meaning and purposes of our landscapes,” said Daniel Robison, president of the Charles Valentine Riley Memorial Foundation.
Riley’s focus on the built landscapes of our natural world resonates distinctly today.
According to the Food and Agriculture Organization of the United Nations, 20 to 40 percent of global crop production is lost annually because of pests, said Sudip Parikh, AAAS chief executive officer and executive publisher of the Science family of journals, in introducing the event.
“This is research that matters to every person on this planet,” said Parikh.
Global crop yields have boomed in the half-century thanks to agricultural intensification: reliance upon high-yield cultivars and monocultures, Landis noted. Agricultural intensification has grown food, fed people and lifted many out of poverty, he said.
Yet intensification, bolstered by the use of inorganic fertilizers and pesticides, is showing its limitations: it is associated with declines in biodiversity, including among the birds and insects whose presence is needed for seed dispersal and pest control.
Changing the landscape can influence how pests and the organisms that attack them move around, Landis noted.
The Dutch have been redesigning their landscapes for centuries – building dikes and pumping out water to create agricultural land – but he offered several contemporary examples as well.
In Iowa, for instance, the United States’ top producer of corn and soybeans, the landscape of rolling hills is prone to soil erosion and nutrient runoff. As part of the multidisciplinary Prairie Strips Project, researchers at Iowa State University sought to slow the pace of water moving off the landscape by planting strips of native prairie perpendicular to the flow of water. The efforts have resulted in 40 percent less runoff, 95 percent less soil export and 90 percent less phosphorous as well as a doubling of bird species.
‘It’s really starting to make an impact,” said Landis.
As part of the 2018 farm bill, prairie strips are a recognized conservation practice for which farmers can secure subsidies to implement, he added.
Landis and panelists emphasized the importance of engaging with the needs of farmers and other stakeholders. Farmers are unlikely to make changes to their landscapes solely for pest suppression, so it is important to understand their other needs to realize multiple benefits.
Said Landis, noting the importance of collaboration to realize benefits beyond pest suppression, “What is the knowledge that researchers and stakeholders can co-produce together that actually allows them to make different decisions to manage their landscape in different ways?”