Comparing Biological and Conventional Chemical Soil Tests in Long‐Term Tillage, Rotation, N Rate Field Study

Abstract

Haney N and P tests were correlated with conventional soil NO3–N and Mehlich III P. Corn and soybean yields were generally not correlated with soil health indicators. Haney and conventional soil test methods had similar laboratory precision as determined by sensitivity ratio analysis. Haney Soil Health Tests generated additional information, particularly about organic C and N fractions, that is not available from conventional chemical soil tests. The Haney Soil Health Tool is a suite of tests integrating chemical and biological factors to provide a sophisticated analysis of soil nutrient availability. This research was conducted to determine if Haney tests (including H3A and water extracts, Solvita 24‐h CO2 evolution, and Soil Health Calculation [SHC]) can add value to conventional chemical soil testing methods and increase knowledge of the effects of tillage systems, crop rotation, and N rate on soil health and corn grain yield. We studied rainfed continuous corn (Zea mays L.) and corn following soybean [Glycine max (L.) Merr.] under three tillage systems and three N rates in a long‐term field experiment in northeast Nebraska. The H3A ammonium, H3A inorganic N, and water‐extractable total N tests detected more differences (significant F tests for main effects and interactions involving all treatments) than conventional NO3–N analysis (which detected the interaction of rotation × N rate). Water‐extractable organic C detected more differences than LOI. There was a three‐way interaction of tillage × rotation × N rate for Solvita and SHC; high N and intensive tillage mostly corresponded to low Solvita and SHC values. We did not expect the treatments to affect P or K directly, but the tillage × rotation interaction was significant for Mehlich III P, tillage for H3A organic P, and N rate for H3A inorganic and total P. Correlation analysis confirmed linear relationships between many Haney and conventional soil tests, and we concluded via sensitivity ratio calculations that the tests offered similar precision.

Managing at a System Level—Considering 4R Nutrient Stewardship and Soil Health Together

“…Individual indicators and corn grain yield were impacted by differences in tillage and nitrogen management practices, and the soil health calculation index values were above the previously set good score for all management combinations (Bavougian et al., ). Soil OM was shown to be impacted by tillage practices as lower OM concentrations were reported with higher intensities of tillage (Bavougain et al., ). When corn grain yield and soil health indicators for the Haney test were measured in the same year, there was no correlation (Bavougian et al., ).…”

“…() evaluated aspects of the Haney soil health assessment on a long‐term research site in Nebraska and concluded that interpretation of the results should shift away from a set threshold to indicate a “good” soil health score and instead measure and track the soil health indicators over time for a specific site. Individual indicators and corn grain yield were impacted by differences in tillage and nitrogen management practices, and the soil health calculation index values were above the previously set good score for all management combinations (Bavougian et al., ). Soil OM was shown to be impacted by tillage practices as lower OM concentrations were reported with higher intensities of tillage (Bavougain et al., ).…”

Complete Issue

“…Soil OM was shown to be impacted by tillage practices as lower OM concentrations were reported with higher intensities of tillage (Bavougain et al, 2019). When corn grain yield and soil health indicators for the Haney test were measured in the same year, there was no correlation (Bavougian et al, 2019). Both reports found relationships of soil health measures to field management practices, and van ES and Karlen (2019) were able to demonstrate that individual tests versus scores are related to corn grain yields, indicting there is value to testing soil health indicators, but interpreting results based on a score of all measurements may not be the best use of the data.…”

“…Interpreting soil health testing through a single score has been the path for results so far, but further analysis is showing that there are better relationships between yield and individual indictors. Bavougian et al (2019) evaluated aspects of the Haney soil health assessment on a long-term research site in Nebraska and concluded that interpretation of the results should shift away from a set threshold to indicate a "good" soil health score and instead measure and track the soil health indicators over time for a specific site. Individual indicators and corn grain yield were impacted by differences in tillage and nitrogen management practices, and the soil health calculation index values were above the previously set good score for all management combinations (Bavougian et al, 2019).…”

“…Bavougian et al (2019) evaluated aspects of the Haney soil health assessment on a long-term research site in Nebraska and concluded that interpretation of the results should shift away from a set threshold to indicate a "good" soil health score and instead measure and track the soil health indicators over time for a specific site. Individual indicators and corn grain yield were impacted by differences in tillage and nitrogen management practices, and the soil health calculation index values were above the previously set good score for all management combinations (Bavougian et al, 2019). Soil OM was shown to be impacted by tillage practices as lower OM concentrations were reported with higher intensities of tillage (Bavougain et al, 2019).…”