The SWAN system has been specifically designed to comprehensively measure indicators of sustainability on farms. The system involves measuring indicators of Soil, Water, Atmosphere and Nutrients on a farm. The soil is important as this is where life begins on a farm through the growing of pastures and crops. Healthy soils result in healthy products. Water is essential to life and it is an important, finite resource which needs to be used responsibly and efficiently. The atmosphere relates to climate change and the effect of greenhouse gases, so it is important to know the extent to which greenhouse gases are being emitted on farms, and what affect that might have on climate change. Nutrients are important as they are necessary for production on farms, but when they are in excess they are wasted as a resource and cause pollution.
Various indicators of each of the aspects of the SWAN system are measured on farms on a yearly or bi-yearly basis providing a score (or index) for soil, water, atmosphere and nutrients, as well as an overall SWAN score. The first time that each farm is measured gives that farm a baseline score against which that farm’s change over time will be observed.