Soils are at the nexus of the atmospheric, geological, and hydrologic cycles, providing invaluable ecosystem services associated with water provision. The immeasurably vital role of water provision is of urgent concern given the intertwined and interdependent challenges of growing human populations, increased agricultural demands, climate change, and freshwater scarcity. Adapting temperate rain-fed cropping systems to meet the challenges of the 21st century will require considerable advancements in our understanding of the interdependent biophysical processes governing carbon and soil-water dynamics. Soil carbon and water are inextricably linked, and agricultural management practices must take this complexity into account if crop productivity is to be maintained and improved. Given the widespread, intensive use of agricultural soils worldwide, it stands to reason that readily adaptable crop management practices can and must play a central role in both soil carbon and water management. This review details challenges and opportunities for utilizing cover crop management to enhance soil carbon stocks and soil water use efficiency in rain-fed cropping systems. A review of the current body of knowledge shows that cover crops can play a more prominent role in soil carbon and water management; however, the more widespread use of cover crops may be hindered by the inconsistencies of experimental data demonstrating cover crop effects on soil water retention, as well as cover crop effect inconsistencies arising from complex interactions between soil carbon, water, and land management. Although these gaps in our collective knowledge are not insignificant, they do present substantial opportunities for further research at both mechanistic and landscape-system scales.

Background and aims Farmers are increasingly interested in regenerating soil health after centuries of soil-degrading practices. However, the most effective soil health regenerating practices (SHRP) and underlying mechanisms that regenerate soil health remain unclear. Our objectives were to determine: (i) how agriculture management, hillslope position, and their interactions affect soil health and root characteristics, and (ii) if there is a relationship between management-induced root characteristics and observed improvements in soil health. Methods Soil and plant root samples were collected from 0 to 120-cm from three management practices: conventional maize-soybean rotation (Row Crop), cattle-grazed pasture (Pasture), and restored grassland (Grassland). Soil health indicators (SHIs) that are responsive to management differences: soil organic carbon, potentially mineralizable carbon, permanganate oxidizable carbon, beta-glucosidase activity, total nitrogen, and autoclaved citrate extractable protein were measured, along with root mass, root mean diameter (RMD), and root length density (RLD). Results Overall SHIs for Pasture and Grassland increased by an average of 54% and 41%, respectively, when compared to Row Crop. Pasture and Grassland management also had twice the root mass as the Row Crop systems. Pasture had the greatest proportion of very fine roots (< 0.2 mm RMD), while Row Crop had the lowest proportion. Individual biological SHIs showed the best negative correlation with RMD and were positively correlated with RLD. Conclusion Soil health regenerating practices that increase total root mass, and fine root mass in particular (i.e., Pasture and Grassland), can lead to vast improvements in soil health regardless of hillslope position.

Soils are at the nexus of the atmospheric, geological, and hydrological cycles; providing invaluable ecosystem services, such as water storage. This compendium explores connections between near-surface soil properties and management practices, with a particular focus on soil-water. This research has explored, in detail, the hypothesis that long-term cover crop management significantly influences near-surface soil properties, and found that rye winter cover crops enhance soil water retention, macroporosity, and water holding capacity, while also augmenting soil organic carbon. This research has also evaluated publicly available Web Soil Survey maps to assess their utility at farm-scale and found that aeolian deposition may have a more significant soil management impact than previously thought. Lastly, this research assessed the efficacy of a novel soil science pedagogy to enhance undergraduate soil science learning and increase student enthusiasm about soil.