Reduced tillage and rotational diversity improve soil health in Missouri

Authors: Veum, Kristen; ZUBER, STACY - University Of Missouri; Ransom, Curtis; MYERS, ROBERT - University Of Missouri; Kitchen, Newell; ANDERSON, STEVEN - University Of Missouri

Submitted to: Agronomy Journal
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 6/20/2022
Publication Date: 7/20/2022
Citation: Veum, K.S., Zuber, S.M., Ransom, C.J., Myers, R.L., Kitchen, N.R., Anderson, S.H. 2022. Reduced tillage and rotational diversity improve soil health in Missouri. Agronomy Journal. 114(5):3027-3029. https://doi.org/10.1002/agj2.21156.
DOI: https://doi.org/10.1002/agj2.21156

Interpretive Summary: Soil health testing has becoming increasingly popular, yet regional interpretations are not widely available due to the influence of local soil and climate factors. This study evaluated soil health indicators across soil and climate gradients in Missouri through a state-wide, on-farm, cost-share program. Soil samples were collected from 5300 agricultural fields across the state and analyzed for several soil health indicators. Soils in different regions of the state responded similarly to tillage and crop rotation practices, showing a clear and substantial benefit of no-till and reduced tillage on soil health. Across the state, diversified rotations with three or more crops exhibited greater biological and physical soil health relative to monoculture or two-crop rotations. This study benefits landowners and advisors by highlighting the value of on-farm datasets from real production systems and by illustrating the potential to increase soil carbon content and overall soil health with adoption of reduced tillage and extended crop rotations in Missouri.

Technical Abstract: The Missouri Soil and Water Conservation Program was initiated by the Department of Natural Resources (DNR) to address challenges related to soil and water degradation by examining soil health under real-world management practices across a range of climate and edaphic conditions. This study leveraged a statewide dataset from a Missouri DNR cover crop cost-share program to analyze the effects of tillage intensity (no-till, reduced tillage, and intensive tillage) and crop rotational diversity (monoculture, two-crops, and three or more crops) on soil health within and across six regions in the state. Management information and soil samples (0-7 cm) were collected from 5300 field sites between 2015 and 2017. The suite of soil health indicators included soil organic carbon (SOC), active carbon, potentially mineralizable nitrogen (PMN), and aggregate stability. Soil particle size distribution was also measured to account for the influence of soil texture on soil health values. Soils in different regions of the state responded similarly to tillage and crop rotation practices, showing a clear and substantial benefit of no-till and reduced tillage on soil health. At the state level, SOC, active C, PMN, and aggregate stability were 15.6, 14.9, 19.4, and 6% greater under no-till, respectively, compared with intensive tillage. Tillage effect size varied across the six regions, ranging from 6.2 to 25.6% for SOC, 7.1 to 27.5% for active C, and 7.5 to 27.5% for PMN. Across the state, diversified rotations with three or more crops exhibited greater SOC and active C (6-8%), PMN (12%), and aggregate stability (5%) relative to monoculture or two-crop rotations, and at the regional scale, enhanced rotational diversity had the greatest impact on aggregate stability. This study highlights the value of on-farm datasets from real production systems and illustrates the potential to increase soil carbon content and overall soil health with adoption of reduced tillage and extended crop rotations in Missouri.