Efficient irrigation is crucial for saving water on farms. A tool called IrriSET was used to compare different irrigation strategies on a dairy farm in New Zealand. The strategies tested were 'just-in-case', 'just-in-time', and 'justified'. The 'just-in-case' strategy used the most water and had the least optimal soil water conditions. The 'just-in-time' and 'justified' strategies performed similarly, but 'justified' was slightly better at keeping soil water in the right range. Overall, a strategy that combines supply (water availability and forecasted rainfall) and demand (soil water conditions) is best for the environment and farm productivity.