Benefits of strategically grazing waterways
With the recent celebration of World Rivers Day on the 27th of September it is timely to talk about the production and whole farm benefits of managing grazing in riparian areas.
Riparian vegetation is vegetation that adjoins, directly influences, or is influenced by, a body of water. This includes vegetation immediately alongside creeks and rivers (including the bank); gullies and intermittent flowlines; areas around lakes and wetlands and on floodplains that interact with a river or creek in times of flood.
Riparian vegetation is often a major link between a catchment and its waterways and wetlands. It is multilayered, consisting of ground cover species, midstorey shrubs and larger, over-storey trees.
Production benefits include:
* Better quality and more reliable alternate water supply if not fouled by stock
* Decreases risk of stock infection by disease and parasites (OJD and Liver fluke)
* Reduces flood gate and fence repair
* Provides shelter benefits for stock and pasture
* Improves stock movement and management
* Increases property capital value and aesthetic qualities
* Habitat for beneficial insects, birds and bats to assist IPM
* Weed spread reduced
Whole farm benefits:
* Provides a buffer strip to capture sediment and nutrients for improved water quality
* Protects stream banks to prevent erosion
* Controls in-stream growth of Typha sp. (Cumbungi) and Juncus sp. (Spiny Rush) through shading
* Lowers localised water tables
* Shades water reducing risk of algal blooms
* Provides Large Woody Debris (LWD) critical for fish habitat and development of deep pools
* Provides wildlife corridors throughout the landscape
* Protects fish and frog spawning sites from trampling
Grazing management in riparian areas
Grazing can have a role in repairing a riparian area but this must be strategic with the aim of long recovery periods leaving sufficient ground cover, especially during the summer storm period. Grazing also has a role in reducing excessive dry matter build up to reduce fire intensity.
Some of the main principles that define strategic grazing are:
1. Grazing periods - are determined by specific goals. For example, in riparian areas, the aim is to graze annual weed species during a growth period (autumn – spring) to assist in the regeneration of native species
2. Grazing intensity - Use high density grazing - short term grazing (1-7 days) with high stock numbers (+100DSE/ha) to quickly utilise or trample dry matter
3. Ground cover – Aim to maintain 100% ground cover at all times and promote a higher density of ground cover prior to summer to intercept high intensity summer and autumn rains
It is extremely important that over the summer-autumn (storm period) 100% ground cover is left at least 20m either side of water courses to filter storm runoff and prevent animal faeces, eroded soil and organic residues from entering the stream.
How to reduce the impacts of grazing on riparian vegetation?
The following are ways that you can reduce the impact that your grazing activities have on riparian vegetation:
*Control stock access to riparian zones by fencing off the area. This should be at least 25m from the top of the bank
*Provide alternate sources of water (if required) so that stock do not need to access waterways
*Strategically graze the riparian area to reduce annual weed burdens, improve ground cover and encourage regeneration of native vegetation
*Maintain 100% ground cover on riparian areas as buffer strips and high levels of ground cover across the remainder of the property
For more tips on managing riparian areas, please phone Senior Land Services Officer NRM Dominic Nowlan on 0409 915 695 or email dominic.nowlan@lls.nsw.gov.au and ask for a copy of the ‘Stock and Waterways’ guide.