An optimisation model was developed to compare the profitability of different forage species on irrigated dairy farms. The model is driven by the energy and protein requirements of the milking cow. The objective of the model is to maximise income, after herd and feed costs, by selecting the area...

Opportunity cropping has been shown to reduce mean annual deep drainage compared to long fallow systems. A question that remained was the effect of added fertiliser nitrogen under each of the cropping systems and whether it would make a significant difference to amounts of deep drainage and to...