Stacking agricultural management tactics to promote improvements in soil structure and microbial activities

Authors: Lehman, R - Michael; Osborne, Shannon; MCGRAW, K - South Dakota State University

Submitted to: Agronomy
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 9/2/2019
Publication Date: 9/12/2019
Citation: Lehman, R.M., Osborne, S.L., McGraw, K. 2019. Stacking agricultural management tactics to promote improvements in soil structure and microbial activities. Agronomy. 9(9): 539. https://doi:10.3390/agronomy9090539.
DOI: https://doi.org/10.3390/agronomy9090539

Interpretive Summary: Linking specific agricultural management tactics to quantifiable changes in soil health-related properties is a key objective for increasing adoption of the most favorable management practices. We used two long-term cropping field studies to illustrate the responses of soil structure indices and microbial activity to additional soil-building management tactics. Both studies had a set of base management tactics that included no-till. In one study, crop rotational diversity was the additional tactic added to the base practice. In the second study, crop residue retention and cover cropping were the additional tactics stacked on the base practice. We found that observable effects of management tactics on soil properties were often dependent on the current crop phase sampled, even though the treatments were well-established. In some cases a single additional management tactic produced a response, two tactics each produced a response, and sometimes there were interactions between tactics. But, importantly, we never observed a negative effect for any of the response variables when stacking soil health building practices in no-till cropping systems. The collective results from the two field studies illustrate that soil health improvements with stacking management tactics are not simply additive and are affected by temporal relationships inherent to the treatments. We conclude that the implementation of multiple positive management tactics increases the likelihood that improvements in soil properties can be documented with one or more of the proxy measures for soil health.

Technical Abstract: Linking specific agricultural management tactics to quantifiable changes in soil health-related properties is a key objective for increasing adoption of the most favorable management practices. We used two long-term, no-till cropping studies to illustrate the variable patterns of response of soil structure indices and microbial activity to additional management tactics including crop rotational diversity, residue management and cover cropping. We found that observable effects of management tactics on soil properties were often dependent on the current crop phase sampled, even though the treatments were well-established. In some cases a single additional management tactic produced a response, two tactics each produced a response, and sometimes there were interactions between tactics. But, importantly, we never observed a negative effect for any of the response variables when stacking soil health building practices in no-till cropping systems. The collective results from the two field studies illustrate that soil health improvements with stacking management tactics are not simply additive and are affected by temporal relationships inherent to the treatments. We conclude that the implementation of multiple positive management tactics increases the likelihood that improvements in soil properties can be documented with one or more of the proxy measures for soil health.