‘Born Again’ Soil (1989)

Many of Australia’s soils are naturally acid, but others have been rendered acidic by agriculture. Treating these soils with lime in the traditional way improves only a shallow surface layer.

Now researchers have developed a machine that can mix lime or gypsum deep into the soil in a series of slots. This allows plants to root more deeply, providing access to more nutrients and protecting them from drought.

With slotting, degraded soils can be re-claimed. Trees established on slots can prevent dissolved nutrients from running into creeks and rivers, causing pollution.