Does soil structure affect water infiltration? Global results from a meta-data systematic review

Soil structure is a crucial component of soil health and quality that significantly impacts water infiltration. Natural or anthropogenic drivers, such as soil management practices, can drastically alter soil structure, which in turn can affect water infiltration. These changes in soil structure have opposing effects on water infiltration into soils and are often difficult to quantify. Here, we present a narrative systematic review (SR) of the impacts of soil structure on water infiltration. Based on inclusion and exclusion criteria, as well as defined methods for literature search and data extraction, our systematic review led to a total of 153 papers divided into two sets: experimental (131) and theoretical (22) papers. That implied a sizable number of in-situ and field experiments that were conducted to evaluate the effects of soil structure on water infiltration under the influence of different land uses and soil practices. Significant effects of soil structure on water infiltration were inferred from analyzing the metadata extracted from the collected articles. These effects were further linked to land use and management, where we demonstrated the influence of three distinct categories: tillage, crop management, and soil amendments. Additionally, significant correlations between infiltration rate and soil structural characteristics were established, with R² values ranging from 0.51 to 0.80, as well as between saturated hydraulic conductivity and soil structural characteristics, with R² values varying from 0.21 to 0.78. Finally, our review emphasized the significant absence of and the need for theoretical frameworks studying the impacts of soil structure on water infiltration.