Structure, carbon, and biodiversity of soil in agricultural water management: Achieving a systemic overview with virtual fields and integrating field data for effective use (VIRTUAALIHALLINTA).

There are high expectations that soil structure, and consequently water management and climate change adaptation, in arable fields can be improved by changes in farming practices (such as implementation of crop rotations and catch crops). However, research-based evidence of the impacts and the magnitude of soil structural changes is still missing. Theoretically good soil pore structure can increase soil moisture, but on the other hand can also increase subsurface drainflow, leaching of nutrients and drying of the topsoil. Moreover, the formation of soil structure is directly linked with soil carbon content and soil biodiversity. These factors (soil structure, carbon, biodiversity and water management) can face significant changes in the near future due to, for example, increased frequency of warm and wet winters and dry spells in the growing season together with developments in farm management related to carbon farming and biodiversity enhancement.

Therefore, this project combines data from best field experiments with novel simulation models to produce holistic understanding on the impacts of soil structure on hydrology and water management under different

cultivation practices. The models describe flow of water in soils and on the soil surface in different weather conditions, take into account soil structural parameters and integrate different data source. Soil data from previous studies and new measurements are used in the models. Thus, the approach can efficiently produce more holistic and systemic understanding on the impacts of soil structure and allows to analyze the impacts on key water balance components simultaneously. Moreover, we will also measure the impacts of different farming practices on soil animal communities. Currently, too little is known about their abundance and diversity in arable soils considering their potential importance in the creation and maintenance soil structure. The studied farming practices can also increase soil carbon content and are of interest from the viewpoint of climate change mitigation and adaptation.