Supporting Michigan farmers using soil health assessment tools: Reflections from an LTER fellow

Graduate researcher, Xinyi Tu, is a graduate student advised by Dr. Sieglinde Snapp in the Department of Plant, Soil and Microbial Sciences Department at Michigan State University (MSU).

Xinyi sampling soil at the Michigan Soybean Farm.

The term “soil health” is similar to that of the health of an organism – it originates from the underlying connection of soil to animal and human health, and to the connection between soil and its living biota. However, there is no concensus amongst scholars as to what soil health means, and various definitions can be found in the literature. This confusion translates to farmers through the creation of  outreach materials, such as decision guides and tools to assess soil health. 

Soil health is usually assessed in terms of chemical, physical, and biological categories.  Chemical indicators of soil health mainly refer to the soil nutrients that you can test using commercial labs and routine tests. Physical indicators can be done on-site and in the laboratory, and are related to the soil structure. Some of these physical indicators can be easily assessed and are recommended by extension educators. These include the resistance of soil to a probe such as a flag. Biological indicators, such as soil enzymes and soil respiration, have emerged in recent decades and are becoming widely used in research studies. Though farmers have shown increasing interest in biological indicators, these tests are not routinely available in commercial labs and few tests are available to use in the field so they are not as accessible as chemical and physical indicators.

My research goal is to support farmers as they build soil health to help protect the environment and buffer against extreme weather and market swings, which are among the many challenges they face today. To better understand how soil health assessments can benefit soybean farmers in Michigan, we partnered with MSU Extension and Michigan soybean farmers to assess how farm management practices impact soil health and yield. Because environmental conditions and soil types vary across Michigan, we recruited farmers from across the state – from the cold environment of the northeast lower peninsula, to the center, to the warm environment of southwest Michigan. 

The farms in southwest Michigan are in the same climatic and edaphic zone as the MSU Kellogg Biological Station. The LTER Main Cropping System Experiment is viewed as a benchmark to investigate soil health and soybean crop response to soil conservation and crop diversity management practices under research managed, long-term experimentation conditions. Connecting LTER Main Cropping System Experiment data with our sites in Michigan Soybean farms is beneficial to investigate the soil health status under different soil edaphic properties. 

Xinyi presenting her soil health assessment tools with advisor Dr. Sieglinde Snapp and a farmer.

As an LTER Fellow, I conducted a survey to better understand the gaps in farmers’ views on good soil health indicators, and their actual use of these indicators. We identified 14 indicators that were commonly used in field assessment of soil health, most of these are descriptive measures or can be evaluated with simple tools. We asked farmers’ opinions of these 14 soil health indicators to identify the ones they saw as most useful. Then asked how often they use to assess their soil’s health. 

We found that farmers were highly interested in a broad range of soil health indicators including biological, chemical and physical ones. Yet, it was crop yield that was used most commonly and indeed many farmer preferred indicators were not used frequently. There appear to be many challenges to using indicators, which could be addressed through developing more farmer-friendly and extension appropriate indicators.

Through the LTER Fellowship program, I had the opportunity to develop a research question regarding soil health assessment on farmers’ field, and their perspectives. I appreciated the chance to better understand their views on soil health indicators. The fellowship offered me the opportunity to learn from soil health research, network with other LTER fellows, get feedback on my work, and present my findings to a large audience.