Nitrogen dynamics of crop and soil subjected to different water and nitrogen inputs, including daily irrigation and steady-state fertilization measurements and modelling

Major carbon and nitrogen fluxes through crop and soil were studied in a series of field experiments. Barley, winter wheat, a grass mixture cut for hay and the energy crop reed canary-grass (Phalaris arundinacea) were studied. The treatments ranged from drought to daily irrigation/fertilization with high doses of water and nitrogen. Crop biomass and nitrogen dynamics above and below ground and incident light as well as soil temperature, moisture and mineral N content were monitored. Litter decomposition experiments were also performed in the field. The results were used to parameterize, validate and improve a set of soil/plant simulation models. Selected experimental results and experiences gained from the water, C and N budgeting and modelling work are presented.