Repairing and preventing soil erosion - Soil Essentials: Managing Your Farm's Primary Asset - page 123

In terms of controlling water erosion, trees find particular use in stabilising
river and stream banks and lowering water-tables. This helps prevent dryland
salinity developing that changes soil chemistry, making soil more dispersible and
more easily eroded. Windbreaks aid greatly in reducing wind erosion if they are
sited carefully and at the same time they provide protection for crops and stock.
Grazing pressure
In normal years of average rainfall it is normal practice for farmers to maintain
some vegetative cover on paddocks to help maintain the soil and pasture health. In
times of drought, and especially if the drought lasts over a number of years, soil
can become very bare indeed, leaving it highly vulnerable to erosion when the
rains do come, or to erosion by wind. One answer to this is to set aside one or more
small areas for hand feeding stock on, which takes the pressure off most of the
farm. In an extended drought even this may not be possible due to over extended
resources, leaving no other option than de-stocking the farm. Managing pastures
by rotational grazing or cell grazing techniques may also result in better ground
cover than set stocking.
Specific methods used to repair erosion
Sheet erosion . Contour rip or cultivate the area and sow it to a pasture or crop at a
high sowing rate. Possibly use diversion banks and grassed waterways to safely take
water from the eroded area to a lower level in the landscape. Possibly need to plant
windbreaks for wind control.
Rill erosion . Contour rip or cultivate the area and sow it to a pasture or crop at
a high sowing rate. Possibly use diversion banks and grassed waterways to safely
take water from the eroded area to a lower level in the landscape.
Gully erosion . Install gully head-works to carry water to the f loor of the gully.
Divert water from the head and sides of the gully using diversion banks. Fence the
gully to exclude stock and revegetate top, sides and f loor of the gully. Build groynes
in the f loor of the gully to trap silt to help fill it over time. On small gullies, batter
the banks using earthmoving machinery, and sow to pasture, trees and shrubs.
Species such as casuarinas and some acacias with multiple fibrous roots are
preferred plant options.
Tu n n e l e r o s i o n . Collapse the tunnel using earthmoving equipment and batter
the edges. Install diversion banks to divert water from the affected area. With
severe tunnel erosion, it may be necessary to use head-works to prevent gully
erosion developing once the tunnels are collapsed by machinery. Fence the area off
from stock and revegetate with deep-rooted species. Gypsum may be needed if the
area is sodic.