Abstract
This thesis focussed on the detection and modelling of soil compaction at different spatial scales. At field scale, fieldwork aimed to analyse and describe the effects of different tillage practices and traffic intensities on the spatial distribution of soil compaction. A one-time inversion tillage was conducted to analyse this measure as a management option to reduce topsoil compaction in conservation tillage. At regional scale, the aim was to develop and apply a new model, which enables a daily assessment of soil compaction risk by considering soil management effects and the dynamic changes of soil properties. The field scale analyses revealed clear patterns of soil compaction depending on the kind of primary tillage practice and traffic intensity as indicated by penetration resistance measurements. Measurements of soil physical properties showed that soil density itself does not allow a functional assessment of soils; i.e. assessment of soil compaction always necessitates the combination of soil density and functionality measurements. The one-time inversion tillage removed the detected dense soil layer in the reduced tilled areas and led to approximately the same soil density as in the continuously conventionally tilled area. The improved soil functionality, which developed during long-term reduced tillage, remained. The SaSCiA-model ("spatially explicit soil compaction risk assessment") was developed to calculate daily soil compaction risk at regional scale by considering soil, weather, crop and machinery information. Spatial crop type information was derived from satellite data and daily soil moisture was calculated by integrating a soil moisture model. SaSCiA was applied to calculate the soil compaction risk on a daily basis for entire years for the two study areas. By considering the dynamic changes of soil moisture, the developed SaSCiA-model enables a detailed spatio-temporal assessment of soil compaction risk, which exceeds all currently available models.
https://macau.uni-kiel.de/receive/diss_mods_00024811
