Simulated seasonal responses of grazed dairy pastures to nitrogen fertilizer in SE Australia: Pasture production

Abstract

Many nitrogen (N) fertilizer recommendations for grazing livestock enterprises are based on cutting experiments, excluding the influence of recycled N in excreta. Grazing experiments are expensive to conduct, and so compromise on variables such as number of N fertilizer rates, replication and number of years of investigation. Biophysical modelling provides an efficient and effective approach to address many of the complexities of field studies. Our study, using the biophysical whole-farm systems model DairyMod, examined the effect of a range of N fertilizer rates on pasture production for five dairy sites through south-eastern Australia over 18 years under both cutting and grazing regimes. T..