Research from Iowa State University in collaboration with the Soil Health Institute reveals that prairie strips can significantly enhance soil health within a surprisingly short timeframe. These strips, consisting of 30-100 ft of herbaceous, perennial plants integrated into crop fields, aim to replicate the ecological benefits of Iowa’s native prairies while minimally impacting crop productivity.
Previous studies have already documented the positive effects of prairie strips on biodiversity, pollinator habitats, erosion reduction, and water quality. However, their specific influence on soil health had not been thoroughly investigated until this recent study, published in March 2023, in the Journal of Soil and Water Conservation.
Significant Soil Health Improvements
The findings indicate that prairie strips can improve soil health measures within just 10 to 12 years. Notably, the research demonstrated enhancements in eight out of 12 soil health indicators, with several others showing improvements at lower levels. The most considerable advancements were observed in:
– **Soil aggregate stability**: Increased by up to 80%, indicating greater resistance to erosion.
– **Microbial biomass**: Boosted by up to 54%, essential for nutrient cycling and carbon sequestration.
– **Soil organic matter**: Enhanced by up to 23%, crucial for maintaining healthy soils.
– **Maximum water-holding capacity**: Improved by up to 7%, allowing soils to retain more water.
Marshall McDaniel, an associate professor of agronomy at Iowa State and coordinator of the study, expressed his surprise at the extent of these changes over a relatively short period. “It has been thought that it would take much longer to see some of these levels of change, especially soil organic matter and maximum water-holding capacity,” he noted.
While some measurements plateaued, aggregate stability and maximum water-holding capacity continued to improve throughout the study.
Research Methodology and Broader Impacts
The study employed a “paired chronoscope” approach, utilizing 15 paired control and treatment sites with prairie strips aged between 2 to 13 years. These sites represented four of Iowa’s seven major landforms and included primarily private farmland. Researchers measured six aspects of soil health in the upper six inches of soil, with a more comprehensive assessment conducted at the oldest strip located at Neal Smith National Wildlife Refuge near Prairie City.
Cole Dutter, who led the study while completing his doctorate in sustainable agriculture and soil science, highlighted additional findings. These included changes in microbial communities extending into adjacent cropland, with elevated enzyme levels that could enhance nutrient availability for crops and boost carbon storage.
The research also revealed that the effects of prairie strips on soil moisture and nutrient availability extended beyond 3 feet (up to 1 meter) into surrounding fields, while maintaining minimal impact on crop yields.
Dutter’s research indicates that prairie strips provide quick benefits to soil health, which may lead to increased crop yields. As he transitions to a faculty position at California State University, Stanislaus, he plans to continue his involvement in prairie strips research.
Accessible Soil Health Assessment Techniques
The researchers emphasized that the techniques used to measure soil aggregate stability and water-holding capacity are straightforward and inexpensive, making them accessible to non-scientists. McDaniel noted, “These DIY tests are great tools that landowners can use to assess soil health on their own fields after implementing management changes like prairie strips.”
For instance, farmers can utilize a smartphone application called Slakes, developed by the Soil Health Institute, to evaluate soil’s erosion resistance. Similarly, the maximum water-holding capacity can be measured easily using common household items such as a funnel and coffee filter.
Funding for the research primarily came from the Foundation for Food and Agriculture Research and the USDA Farm Service Agency, with additional support from the National Science Foundation and USDA Hatch funds.
As the research continues to unfold, it underscores the potential of prairie strips not only to restore soil health but also to enhance agricultural sustainability across diverse farming landscapes.
