University of Natural Resources and Life Sciences, Vienna (BOKU) - Research portal
Gewählte Doctoral Thesis:
Peter Scholl
(2017):
Investigation of root-induced changes of soil hydraulic properties based on two common cover crop species - tap rooted mustard (Sinapis alba L.) and fibrously rooted rye (Secale cereale L.).
Doctoral Thesis - Abteilung Pflanzenbau,
BOKU-Universität für Bodenkultur,
pp 124.
UB BOKU
obvsg
- Abstract:
- In the context of establishing resilient, sustainable agricultural production systems cover crops are regaining in importance. Focusing on the crop production factor water, a combined approach of laboratory and field studies was chosen to investigate and quantify root-induced changes of soil hydraulic properties by mustard (Sinapis alba L., tap rooted) and rye (Secale cereale L., fibrously rooted) as typical examples for cover crop species vs. an unplanted control. A modular laboratory setup (Σ12 soil columns) for drainage experiments under controlled conditions facilitating measurements of soil water content (TDR-sensors) and matric potential (tensiometers) in six 10 cm-layers per column was developed. Tests confirmed that the laboratory setup allowed identifying temporal changes of soil hydraulic properties induced by soil settlement and root growth. The presence of roots led to a significantly reduced decrease in total porosity. Field measurements were performed at the study site Groß-Enzersdorf (Lower Austria) to investigate the dimensions of root effects on soil hydraulic properties under natural conditions vs. other potential driving forces caused by management or environment. In contrast to laboratory experiments, significant influences of different soil covers on most hydraulic properties could not be observed under field conditions; contribution of plants was substantially less compared to one mechanical soil disturbance. Wetting-drying cycles were identified as dominant driving forces explaining short term hydraulic property changes within the season. Wetting-drying cycle intensity was found to be the best single predictor for the temporal drift in median pore radius and pore radius standard deviation. Especially the laboratory experiment displayed significant effects with heterogenization of the pore system as dominant process of root induced structure formation.
- Betreuer: Kaul Hans-Peter
- 1. Berater: Loiskandl Willibald
- 2. Berater: Bodner Gernot