Groundcover is the layer of grass, other plants and plant litter that protects soil against erosion.
Groundcover is recognised as a major benefit to both agricultural production and in mitigating risks to water quality. It protects soil from the impact of rain, slows rainfall run-off and helps keep soil moist for pasture growth and productivity. It also helps filter fertilisers, animal droppings and other pollutants before they reach dams and creeks. Groundcover of 80 to 100 percent made up of predominantly perennial pasture species is ideal.
Groundcover often becomes run down through over-grazing, uncontrolled stock access, poor understanding of pasture targets and feed availability, invasion by pests and feral animals such as rabbits, annual weeds, or from overuse by recreational activities. Undergrazing may also lead to a decline in feed quality and clumping of grasses over time leading to patchy groundcover, excessive waste and changes in pasture composition.
In a natural or well managed state, pastures of mostly perennial grasses can provide year-round groundcover. Perennial species are deep-rooted and last for several years. Perennial grasses can be native or introduced, although locally native grass species can often be better adapted to the conditions of the local area.
Perennial species offer better pasture cover during drought by accessing moisture from deeper in the soil than annual species. They also produce higher pasture yields and better feed quality in summer and autumn. This means less need for supplementary feeding of stock. Essentially, perennial species offer better groundcover over longer periods of time. This helps minimise erosion and maximise the ability of pasture to filter and trap pollutants before they enter waterways. This also keeps nutrients on the land benefitting pasture condition over time.
What you can do
- Maintain at least 80 percent groundcover to minimise erosion and maximise moisture retention. (Groundcover of 100 percent means you cannot see the soil. Zero groundcover is bare soil.)
- Subdivide paddocks and use rotational grazing to allow pasture to rest and re-grow after grazing.
- Encourage perennial species that are deep-rooted and live for several years to make your pastures more resilient.