Who will answer their questions? A mixed-methods study on supporting the research needs of producers innovating in soil health

Abstract

Producers who are innovating in soil health generate complex and multidisciplinary questions about their ecosystems at a rate that far outpaces the ability of academia to address. Exploring these questions represents one piece of the intellectual labor needed to implement soil health practices successfully on a working farm or ranch, and many producers engage in independent on-farm research projects to provide this insight. Such producer-led research represents a large and untapped resource which could supplement academia’s current on-farm research programs. Furthermore, there is a lack of responsive and cost-effective soil health metrics to quantitatively evaluate the soil health outcomes of single-season management changes. My mixed-methods research included qualitative interviews and thematic analysis with producers and academic researchers alongside the evaluation of two soil health indicators. First, to explore collaboration opportunities for on-farm experimentation I conducted semi-structured interviews with 10 academics and 7 producers. The results showed that (1) regenerative agricultural operations are more complex to manage than their conventional counterparts, (2) neither academia nor soil health testing were mentioned as a resource by the producers to address this complexity, and (3) all the researchers (academia and producers alike) were interested in doing more highly collaborative on-farm research, despite the additional challenges inherent in on-farm research. Second, to find a soil health indicator that producers could use to help them quantify single-season changes in soil health, I evaluated aggregate stability using the SLAKES smartphone app and the tea bag index for their sensitivity to changes in management in long-term experimental and individual farmer field soils with paired treatment/control strips. I developed new protocols for the tea bag index that only require equipment readily available to producers, then incubated green tea in the field for 30 days and in a laboratory incubator for 5-90 days, to determine if green tea decomposition varied between treatment and control soils. I measured aggregate stability of the same paired soils with the SLAKES app, and correlated the SLAKES and green tea data with commercial lab soil health and microbial community test results. Across this study, the decomposition of green tea was only able to differentiate between treatment and control soils for 18\% of the measurement points. Looking at long-term experiment soils with known differences in soil health, green tea was only able to differentiate treatment contrasts for 22\% of the measurement points. I evaluated varying the decomposition duration and found that there was no one time point which consistently detected differences between treatment contrasts across sites. The SLAKES app could not differentiate between any of the treatment contrasts. I found no correlations between green tea decomposition and other laboratory measures of soil health except for a strong negative correlation with aggregate stability from the SLAKES app. I cannot recommend that producers invest their time to perform either one in treatment/control trials on their farms.