Grassland management intensity determines root development, soil structure, and their interrelationship: Results of a regional study of Leptosols in the Swabian Alps

Background

Soil structure is a key indicator of the functioning of soil processes in grasslands, which is influenced by site conditions and management.

Methods

In this study, we investigated soil structure and its relationship with root growth in 31 Leptosols under different grassland management intensities using X-ray microcomputed tomography. A close relationship between land use intensity, soil structure, and root growth was observed.

Results

Our results show that land use type affects root development and soil structure. Pastures had more developed roots and more structured soils than meadows and mown pastures. However, all pastures were unfertilized, while meadows and mown pastures had both fertilized and unfertilized plots. Although no significant differences were found in the unfertilized plots, sample size was limited. In particular, fertilization negatively affected root growth and soil structure, resulting in significant differences between fertilized and unfertilized grasslands. Mowing frequency also had an effect on soil physics, but to a much lesser extent than fertilization.

Conclusions

Increased land use intensity, characterized by increased fertilization and more frequent mowing, reduces root growth and adversely affects soil structure. Therefore, X-ray microcomputed tomography is a suitable method to investigate the relationship between soil structure and roots in the soil.