Cover Crop and No-Tillage Impacts on Soil Health Indicators over a Growing Season.

Commercial soil health tests are emerging as a new resource available to researchers and farmers trying to quantify the health of their soil. Many question the usefulness of the data because there currently is no baseline with which to compare results. Some also wonder if there is an ideal time period to collect samples for these analyses, both to reduce variability in results and for the farmer’s sampling convenience, or if the timing of sampling is not critical. In previous years of this study, the Cornell Comprehensive Assessment of Soil Health (CASH), the Haney-Solvita test, and a phospholipid fatty acid (PLFA) test were conducted once per year during the V3-V6 growth stages in corn (Zea mays L.), on multiple sites across Indiana with various cover crop and tillage treatments. In 2017, a subset of three sites with cover crop treatments and no cover crop comparisons, and one site with a tillage and no cover crop conventional neighbor, were sampled multiple times throughout the growing season. These samplings occurred at various stages prior to and during cash crop growth, to assess the impact of cover crop treatments and no-tillage on soil health indicators across time. A PLFA soil health test was conducted by the University of Missouri Soil Health Assessment Center at each timing, along with soil respiration and active carbon measurements by the Cornell Soil Health Testing Laboratory. One full Cornell CASH occurred at the third timing, which was between the V3-V6 growth stages in corn, for comparison to previous years’ data. The objective of the 2017 work was to determine a standard sample time for commercial soil health tests that can most accurately represent changes occurring in soil health indicators during a given year.