Hydraulic Engineering Commons^™

The Challenges Of Incorporating Urine And Dung Patches In Process-Based Modelling Of Grazed Agricultural Systems, Val O. Snow, Richard J. Eckard, C. Alan Rotz, Ian R. Johnson, Nicholas J. Hutchings

International Congress on Environmental Modelling and Software

Animals are well known to be important in lateral transfers of nitrogen within the farm boundary. Those transfers can be categorised into those that are: (a) primarily random and small- scale dung and urine patches within a grazed paddock, (b) larger and systematic transfers resulting from preferred grazing and resting areas and (c) those that are additionally mediated by management actions such as manure management from housing systems. We review how key simulation models treat the random category of nitrogen transfers and develop recommendations for usage and further development. While urine patches are clearly understood to be important in N …