Linking soil health, hydrology, and agroecosystem services through expert elicitation

Abstract

Agricultural soil health management practices, such as cover cropping, reduced tillage, and diversified crop rotations, are becoming more widespread. However, the reported effectiveness of these practices in achieving agroecosystem service goals such as enhanced crop yield and improved water quality has been mixed. In this study, we conducted a survey of 386 researchers and stakeholders with expertise in North American agricultural systems, asking about the perceived impacts of soil health management practices on hydrology and the role of hydrological processes in mediating the impacts of different practices on agroecosystem services. We found that (in order of importance) cover crops, reduced tillage, and diverse crop rotations are perceived as the most important soil health practices with generally positive agronomic and environmental outcomes, but with significant regional variability. Respondents mostly (though not universally) agreed in direction with reported literature on the effects of these practices on outcomes like soil hydrological properties and yield, but survey responses had less variability than the literature. Experts responded that hydrologic and landscape factors, especially soil texture and soil drainage status, were important controls over the ability of soil health practices to meet agroecosystem service goals. Additionally, respondents perceived that hydrologically mediated impacts of soil health management on outcomes such as nutrient losses, irrigation requirements, and yield were more common than direct impacts of the practice alone. These expert opinions suggest that effective soil health management strategies should be driven by desired agroecosystem outcomes and that hydrological, landscape, and soil conditions provide a lens to target and implement these practices.