Why Manage your Native Pastures?

Native pastures are vital for the long term productivity and sustainability of many grazing enterprises in the Mid and Upper North of SA.

Native pastures have the ability to change in composition with season and respond to changes in soil fertility and grazing pressure. The challenge for land managers is to encourage or maintain diversity in a changing environment and avoid dominance by annual species.

But native grasses are vulnerable to overgrazing, particularly when set stocked for long periods. In many native pastures, after many years of set stocking, the dominant plants are now annuals such as wild oats and barley grass, as the native perennial grasses cannot thrive under constant grazing.

Better grazing management of grasslands can increase the biodiversity of native pastures and the profitability of livestock enterprises, resulting in a win-win situation for farmers and the environment.

Native Pastures Management

To manage native pastures so they reach their full production potential, the most important thing to remember is rest is best! Rest is best because native grasses are perennial plants – that is, they survive for many years and regrow from the same roots so they need time to recover from being grazed.

Perennial plants grow from a long lived base of roots and growing tips which can last for many years. The plant may have dead material standing above the ground with the growing tips at the base of the plant just waiting for moisture so that they can grow. A rainfall event activates growth in the plant base and the plant sends up shoots.

As the above ground parts of the plant grow, the roots of the plant also grow. Roots are very important to the plant. Not only do they capture moisture and nutrients from the soil, they also store excess energy produced by the leaves safely below the ground as starch. When the top of the plant is eaten by an animal, the stores of starch in the roots provide the energy for new shoots to be produced.

If a perennial grass plant is grazed – and to keep it healthy, grasses need to be grazed – it has the ability to recover quickly if it is not grazed again before it has had time to regrow its roots. If it is grazed again, the whole plant is weakened because it does not have a renewed store of energy in its roots from which to fuel new stem and leaf growth. If this happens continually, as it does in a set stocked pasture, the perennial plants gradually get smaller and smaller, and so weak that eventually they die.

Under natural conditions, grazing animals do not stay in one place and eat. They like to eat fresh grass and herds of animals will move on to fresh pasture almost daily, leaving behind large amounts of fertiliser and grasses which have time to recover before the animals return. Fences restrict animals to one area, where they are forced to eat the same plants for days, and sometimes even months.

Set stocking over a period of years results in annual grasses dominating over the perennial grasses and the pasture loses significant productive capacity.