The effects of long-term fertilizations on soil hydraulic properties vary with scales

• DOI: 10.1016/j.jhydrol.2020.125890
• Publication Date: 2020-12-24T23:06:32Z
• Authors: Xiaoxian Zhang; Andrew L. Neal; John W. Crawford; Aurelie Bacq-Labr...; Elsy Akkari; William Rickard
• Keywords: Tortuosity; Soil structure

Soil structure is an indicator of soil quality and its alterations following cropping system conversion or fertilization change evolve slowly. How such vary with scale remains elusive. We investigated this based on the Rothamsted long-term wheat experiment (since 1843) in UK. Triplicate cores 7 cm high 10 diameter were taken from plots that have been under different fertilizations returned to natural woodland for more than one century imaging using X-ray computed tomography voxel size being 40 µm. then broke each core sampled three aggregates it scan 1.5 For aggregate sample, we calculated pore distribution, permeability tortuosity. The results showed >170 years ago reshaped differently between scale. Macro-porosity pores (>40 µm) unfertilized fertilized inorganic fertilizers was low poorly connected top soil, compared those given farmyard manure woodland. In all treatments, images hydraulically anisotropic their horizontal direction higher vertical direction, whereas comparatively isotropic. affected image porosity at significantly scale, permeable other treatments. It also found no-fertilization complete fertilizers, fertilizing without phosphorus over past 20 increased but not cores. Fertilization tortuosity macropores intra-aggregate pores, no-fertilization. Porosity-permeability relationship fertilisers followed a power law R2 > 0.8. contrast, trended as increased. revealed transport ability responded carbon increasing, asymptotically while cores, especially component, exponentially.