Principal Investigator: Laura Van Eerd
Research Institution: University of Guelph
Timeline: April 2015 – March 2018
- Assess the validity and applicability of the Haney soil health test in Ontario.
- Compare the nitrogen (N) and phosphorus (P) fertilizer recommendations of the Haney soil health test to Ontario soil-based recommendations.
- Determine the influence of time of sampling on the Haney soil health test.
- Quantify cropping system management practices that, over the long-term, affect (negatively or positively) soil health.
- The increased knowledge of management practices that enhance or maintain soil health will enable growers to manage production practices for soil health and could increase crop productivity and resiliency to extreme/challenging weather conditions.
- The results contribute to the development of a provincial recommendation of the most appropriate measure of soil health.
- The validation and applicability of the Haney soil health test and the applicability of the Haney test to predict N and P fertilizer requirements may allow for cost effective tests; alternatively, if results suggest that the test is not applicable in Ontario it will save growers money by avoiding investment in an ineffective test.
Healthy soil is critical to crop productivity, resiliency and ultimately profitability of Ontario’s farmers. There is no accredited Ontario soil health test and there is considerable debate as to the ‘best’ soil health indicator. Dr. Rick Haney at the USDA Agricultural Research Services has developed a new soil health test from rangeland in Texas. The Haney test has been promoted for use throughout USA. This test may be attractive to Ontario farmers as it is relatively cheap and commercially available. But the validity and applicability of the Haney soil health test to detect differences in soil health of diverse cropping systems in Ontario is not known. Therefore, we evaluated the Haney test, Solvita CO2-Burst test https://solvita.com/soillabtest/ (used in Haney test) and Solvita SLAN tests https://solvita.com/slan/, using long-term experiments in Ontario at Ridgetown, Elora and elsewhere in 2015 and 2016. Dr. Van Eerd’s long-term cover crop experiment was used for the evaluations along with long-term experiments comparing two tillage systems (no-till and strip tillage) to conventional fall moldboard plow tillage and 5 to 8 crop rotations (crops include corn, soybean, winter wheat, alfalfa, red clover, spring cereals). Furthermore, the long-term P and K experiments established in 2008 at Ridgetown, Elora, Lucan, and Bornholm were used to evaluate the recommended P fertilizer applications provided by the Haney soil test, as well as Solvita and SLAN.
Medium-term cover cropping (6 yrs) improved soil health compared to the no cover crop control based on soil organic carbon. Solvita CO2-Burst test and SLAN test detected some cover crop treatment differences but the results were not consistent between years. The Haney soil health test did not detect cover crop treatment differences in either year. In the long-term tillage system and crop rotation experiment at Ridgetown and Elora, Solvita CO2-Burst and SLAN identified no-till/zone tillage systems and crop rotations with winter wheat, red clover and alfalfa as having better soil health. At these two sites, Solvita CO2-Burst and SLAN correlated to soil organic carbon and total N. These results were consistent with published work using the Cornell soil health assessment and suggest the usefulness of these soil health tests in grain crop systems. Preliminary Solvita CO2-Burst results from the long-term P and K fertility trials were consistent with expectations of little differences among treatments because these trials were only recently established (2012-14). The timing of collecting soil samples may influence results as indicated by the cover crop trial and P&K fertility trials, which suggests that growers need to be consistent in timing of soil health testing. This research increased our understanding of the impact of tillage system, crop rotation, cover cropping and fertility on soil health. After 6-yrs of summer-annual cover cropping, cover crops improved soil health relative to the no cover crop control, thus, identifying cover cropping as a soil health BMP.
In conclusion, the lack of consistency among years and within cover crop treatments in the long-term cover crop experiment suggests that the Haney soil health test, Solvita® CO2 burst, SLAN tests cannot detect subtle soil differences. But with larger differences in soil properties observed in the tillage systems and crop rotation experiments at Elora and Ridgetown, results suggest that the Solvita® CO2 burst and SLAN tests may be useful indicators of soil health. Timing of soil sampling may be important in the interpretation of the results. Therefore, Solvita® CO2 burst and SLAN tests should be done at the same time of year to allow for more consistent interpretation of results over time.
External Funding Partners: Ontario Ministry of Agriculture, Food and Rural Affairs (OMAFRA) – University of Guelph (U of G) Partnership Agreement: Environmental Sustainability theme. The Elora research station and Ridgetown Campus are two of 15 Research Stations owned by the Agricultural Research Institute of Ontario and managed by the University of Guelph through the Ontario Agri-Food Innovation Alliance, a collaboration between the Ontario Government and the University of Guelph.
Project Related Publications:
Chahal I. and L. L. Van Eerd. Temporal dynamics of soil health indicators using a medium-term cover crop experiment in a temperate, humid climate. PlosONE Accepted June 2020.
Chahal I. and L. L. Van Eerd. 2019. Quantifying soil quality in a horticultural-cover cropping system. Geoderma. 352, 38-48.
Chahal, I. and Van Eerd, L.L. 2018. Evaluation of commercial soil health tests using a medium-term cover crop experiment in a temperate climate. Plant and Soil. 427:351–367. https://doi.org/10.1007/s11104-018-3653-2 .