title: Changes in soil mechanical and hydraulic properties through regenerative cultivation measures in long-term and farm experiments in Germany
Creators: name: Bilibio, Carolina
name: Weber, Tobias Karl David
name: Hammer-Weis, Markus
name: Junge, Stephan Martin
name: Leisch-Waskönig, Simeon
name: Wack, Janos
name: Niether, Wiebke
name: Gattinger, Andreas
name: Finchk, Maria Renate
name: Peth, Stephan
Publisher: name: Universität Kassel
Year: 2024
Subjects: subject: aggregate stability
subject: compost
subject: cover cropping
subject: farm experiments
subject: field-saturated hydraulic conductivity
subject: mulch
subject: reduced tillage
subject: shear resistance
subject: soil penetration resistance
classificationCode: 500
subject: 500
classificationCode: 630
subject: 630
classificationCode: Deutschland
subject: Deutschland
classificationCode: Kompost
subject: Kompost
classificationCode: Aggregat <Chemie>
subject: Aggregat
classificationCode: Gründüngung
subject: Gründüngung
classificationCode: Mulch
subject: Mulch
classificationCode: Bodenbearbeitung
subject: Bodenbearbeitung
classificationCode: Bodenmechanik
subject: Bodenmechanik

description: <p>Regenerative agriculture has been associated with improved soil structure and soil fertility. However, conclusive evidence of its efficacy has remained elusive owing to a lack of long-term experimental studies. In this study, we assessed the impact of diverse regenerative agricultural measures on soil mechanical and hydraulic properties and indicators. Tested treatment factors included reduced tillage versus plowing, along with different levels of compost, mulch, and the application of ferments and compost tea. We measured in situ soil strength via soil penetration (from 0 to 0.8 m depth) and shear resistance (at 0.08 and 0.23 m depth) and assessed field-saturated hydraulic conductivity and ex situ soil aggregate stability (at 0.07 and 0.23 m depth). The experiments were conducted at five sites in Hesse, Germany, including one organic long-term experiment (LTE, since 2010) in Neu-Eichenberg and three organic and one conventional on-farm experiments to cover different soil types, weather conditions, and field practices. The soil types are classified as Luvisol and Vertic Cambisols, and the soil texture ranges from silt loam to silty clay loam. In the LTE, significant differences in aggregate stability and shear resistance were noted between treatments, with a higher geometric mean aggregate diameter at 0.07 m depth in 2021 and 2022 and a higher shear resistance at 0.19 m and 0.23 m in 2020 and in 2021, respectively, in the reduced tillage systems. However, no significant differences were observed among treatments for field-saturated hydraulic conductivity, which was overall very high, showing that reduced tillage did not negatively influence saturated infiltration, albeit bulk density is higher than in the conventionally plowed system. The soil penetration resistance was generally higher for the reduced tillage treatments across depths of 0.0–0.30 m, albeit not statistically significant (p &gt; 0.05). Significantly higher water-stable aggregates and geometric mean diameters were observed for regenerative agricultural treatments in three of the on-farm experiments at a depth of 0.07 m. The shear resistance was significantly higher in regenerative agriculture units in specific years and depths. Although the outcomes are encouraging, the variability of the effects of reduced tillage and organic amendments in affecting soil properties highlights the need for further long-term research including farm trials. This is essential to fully understand the effects of regenerative practices on soil physical quality.</p>