Natasha Hoover, research scientist at ISU’s College of Engineering, collects a sample of poultry manure as part of the LAIYERS study. (Photo: Joseph Hopper/Iowa Soybean Association)
Researching the Potential of Poultry Manure LAIYERS dives into nutrient and environmental aspects of poultry waste BY KRISS NELSON
W
e may never answer such questions as “What came first, the chicken or the egg?” or “Why did the chicken cross the road?” but a new study will unlock some answers about how poultry manure affects soils and provides nutrients that crops can best utilize. Through a new multiyear study, Land Management for Improved Yield Environmental Resilience Sustainability (LAIYERS), researchers hope to learn more about nutrient availability to plants and poultry manure’s effect on overall soil health. LAIYERS is the second generation of a study started in the late 1990s.
24 | JUNE 2022 | IASOYBEANS.COM
The Iowa Egg Council initiated both studies to understand poultry manure’s effects on water quality. “When our study was first started in the 90s, poultry manure was considered a waste product,” says Michelle Soupir, interim associate dean, graduate college and professor & associate chair for research/extension at Iowa State University. “We want to figure out how much manure can be applied before impacting water quality and how to dispose of manure without building up phosphorous in the soil.” There was enough interest in establishing new field plots 20 years later, expanding on previous studies.
“The previous research only considered two manure application rates, and the plots were different sizes,” Soupir says. “We designed the new site to be a comprehensive study of the sustainability of poultry manure integrated into a system using best management practices.”
The study LAIYERS includes 27 plots with a range of different applications using strip-till (including cover crops), splitting urea ammonium nitrate (UAN) fertilizer and leveraging varied manure application timings. There is an emphasis on not increasing
