Location: Soil, Water & Air Resources ResearchTitle: Reanalysis confirms soil health indicator sensitivity and correlation with long-term crop yields Author
|Van Es, Harold - Cornell University - New York|
Submitted to: Soil Science Society of America Journal
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 2/9/2019
Publication Date: N/A
Interpretive Summary: Soil health assessment is essential to sustaining land resources and meeting global food, feed, fiber, and fuel demands. This is a re-analysis of data from an earlier North Carolina study that concluded soil health metrics had minimal value in agronomic studies and did not correlate with crop yield. We counter those conclusions and document that Comprehensive Soil Health Assessment (CASH) data differentiate well among long-term soil and crop management effects and correlate with crop yield. Indicators of easily decomposed forms of organic matter showed the most effects from tillage and organic treatments which in turn affected corn and soybean yields. This report will be of high value to producers, soil-test laboratories, non-governmental organizations, Cooperative Extension Service and Natural Resource Conservation Service (NRCS) personnel, and researchers interested in soil health assessment and management.
Technical Abstract: Soil health (SH) refers to the ability of a soil to function and provide ecosystem services. This study reanalyzes SH data from long-term agronomic management experiments in North Carolina and corrects erroneous conclusions regarding the utility of SH test metrics and their correlation with crop yield. Data for 15 SH indicators using the Comprehensive Assessment of Soil Health (CASH) framework from three long-term trials within mountain, piedmont, and coastal plain areas of North Carolina were analyzed to assess effects of tillage intensity and organic vs. conventional management. This included four soil biological indicators - organic matter (OM), active carbon (ActC), respiration (Resp) and protein (Prot); four soil physical indicators - available water capacity (AWC), water stable aggregation (Agstab), surface and subsurface penetration resistance (SurfHard, SubHard); and seven soil chemical (fertility) indicators (P, K, Mg, Fe, Mn, Zn, pH). Corn (Zea mays L.) and soybean (Glycine max L. Merr.) yield data and SH indicator values were correlated using site-specific and multi-site datasets. Long-term management practices had the most detectable impact on biological SH indicators. Tillage intensity had a greater impact than organic vs. conventional management and correlated well with mean corn and soybean yields. Labile C and N indicators (ActC, Protein, Resp) and Mn showed the strongest correlation with crop performance. Contrary to previous conclusions, SH indicators measured within Ultisols and minor Entisol inclusions were responsive and able to detect differences among agronomic management practices.