Research Summary: The Balance Between Environmental and Management Factors Effect on Soil Health Indicators

Tu, X., DeDecker, J., Viens, F. h. o., & Snapp, S. h. o. (2021). Environmental and management drivers of soil health indicators on Michigan field crop farms. Soil & Tillage Research, 213 p.105146- https://doi.org/10.1016/j.still.2021.105146 

            In this study, Tu et al. measured how environmental and management factors drive soil health indicators on 35 working farms in Michigan. Producer management practices of tillage intensity and crop diversity from the past six years were determined through a survey of the cooperating producers. Soil health indicators of soil organic carbon (SOC), permanganate oxidizable carbon (POXC), carbon mineralization, and aggregate stability were measured. Environmental factors of moisture and clay content drove much of the observed SOC and POXC values. This indicates that these are largely dependent on factors outside of the producer’s control. While crop diversity was not associated with SOC or POXC levels, tillage intensity reduced POXC levels but had no effect on SOC.

Carbon mineralization was primarily driven by crop diversity and clay content but was largely unaffected by tillage in this study. Aggregate stability was primarily driven by crop diversity, likely due to increased residues helping to stabilize soil aggregates. This study shows how many factors other than management practices affect soil health indicators. Producers in Virginia should keep in mind that factors outside of their control might be influencing soil health indicator values. As it is well established that reduced tillage intensity and increased crop diversity increase soil health, producers correctly utilizing these practices should not be concerned about a low indicator value. If low indicator values start to become a trend over time, then discussions on management practice alterations will be relevant. However, changes to management practices based on soil health indicator values alone should be made with extreme caution.