Predictions of growth and nutritional value of forage leys with a dynamic model

The model was tested on independent data from four experiments in three different locations over two or three years and at three levels of N fertilizer, making a total of 27 data sets (time series). The root mean square differences between predicted and observed values (RMSP) in percentage of the mean of observed values were for DM: 12-13%, for CP: 10-14% and for ME: 3-4%. Predictions of DM and ME two weeks before harvest were as accurate as predictions one week before harvest, but predictions of CP were less accurate for a two-week prediction.