To be sustainable, farm enterprises must pass two tests of sustainability. They must be environmentally and economically sustainable.

Environmental sustainability is a long term view for future generations. It focuses on the soil, water and vegetation. It requires an examination of soil structure, soil fertility. soil biology, salinity, acidity and what is happening to these soil dimensions over time. It looks at water and rangelands and their ability to continue to support livestock indefinitely.

Having satisfied the tests of environmental sustainability, producers must consider what is the most profitable enterprise mix? This requires re-examination every year because of changing markets, technology, cost of inputs and other factors that determine profit. Managers must be able to work it out and do the calculations.

If the enterprises pass both tests, grazing and farming will be viable. The environmental tests consider viability for future generations. The economic tests must be re-applied every year as nobody can guarantee costs, prices or technology for the long term.