| Popis: |
Processes which are involved in nitrogen modeling on a regional scale are discussed, and the performance of some models in relation to measured field data is analyzed. Data on nitrate-N emission for different fertilizer strategies are simulated on a national scale, and cost comparisons for different control strategies are provided in relation to nitrate-N emission reduction. Uncertainties in simulation results as well as in measured field data are discussed. It is concluded that the simulation model is realistic and meaningful, and provides a good basis for policy analysis. |
