Dairy effluent overview in Gippsland
Note Number: AG0496
Updated: August 2008
As in other parts of Victoria and Australia, dairy herd sizes have been increasing for many years in Gippsland, allied with improvements in dairies, tracks and pastures. However, in many cases improvements in effluent management have not kept pace with these changes. The result on many farms has been the wastage of good, productive land at the disposal site through waterlogging and nutrient overload, the potential for off-farm pollution, and the wastage of nutrients and organic matter which could be productively used on the farm.
The proper management of dairy shed effluent is important as it is rich in nutrients such as nitrogen, potassium and phosphorus and contains large numbers of bacteria. For these reasons dairy shed effluent is potentially both very useful and harmful. Excess nutrients and bacteria (from a range of sources) in creeks and rivers is a problem in Gippsland as many towns take their water supply from local streams. The region's major river systems, the Avon, Latrobe, Macalister, Mitchell, Tambo and Thomson, empty into the Gippsland Lakes, an important area for tourism and nature conservation.
Dairy farm effluent systems have evolved from a shovel and manure pile alongside the old walk-through dairy in the 50s, to options which emphasise the collection, storage and recycling of nutrients to pastures and crops.
Despite these advances, many farms have continued to run effluent to a gully or hillside where it can cause problems. As you drive around Gippsland you can see many examples of effluent management systems that aren't working properly. Dark green lines running across paddocks and onto roads or into drains and creeks, or paddocks covered in brown liquid and weeds are tell-tale signs that there is still some way to go to achieve the goal of containing all the effluent on the farm and recycling nutrients back to pasture.
Effluent systems for Gippsland
Although Gippsland is only a small part of Victoria, there is great diversity of dairy farm situations and farmer management styles. Hence, the options suitable for different districts within Gippsland and individual farms vary widely.
Over 60% of Gippsland dairy farms depend on rainfall for their productivity. Rainfall is high, ranging between 900 and 1500 mm per year. Areas such as the Strzeleckis also have very steep hills with a large number of flowing gullies and creeks in the winter and spring. Areas such as Trafalgar and Longwarry have poorly drained flats with high water tables in winter. High rainfall, high watertables and steep terrain may make the construction of ponds of adequate size to hold effluent over the winter and spring months very difficult. Steep terrain may also make desludging ponds difficult and expensive. A small sump or pond and regular application of effluent to pasture via a travelling irrigator may be more feasible in such areas, particularly where soils are highly absorbent as in the Warragul district.
In areas like Yarram where rainfall is not as high but groundwater is available, farmers are tending to install spray irrigation systems to give added feed security. Usually, such country is flat or undulating and pond construction and maintenance is quite feasible. A very good option in this situation may be to store effluent over the winter and spring and pump it through the irrigation sprays over the drier months.
In the Macalister Irrigation District dairy farmers depend mostly on flood irrigation but an increasing number are also installing spray irrigation systems. The land is relatively flat, rainfall is low and pond construction and desludging is usually inexpensive and simple. In this area effluent storage ponds are probably the best option, with effluent being spread with flood irrigation water in the warmer months.
Farms on the Snowy River flats at Orbost (and to a lesser extent on the Macalister Irrigation District and elsewhere) are unusual in that they are subject to periodic inundation from the flooded river. Ponds are probably not a good option in this situation but direct spreading of effluent via a travelling irrigator should meet requirements quite well.
DEPI Contact/Services Available
Further advice can be obtained from your nearest DEPI office.
Ellinbank (03) 5624 2222
Leongatha (03) 5662 9900
Maffra (03) 5147 0800
For further information please see the other Managing Effluent pages.
This Agnote was developed by Ken Slee, Maffra and Colin Waters, Ellinbank March 1996.
It was reviewed by Barrie Bradshaw, Ellinbank, Farm Services Victoria August 2008.
Published and Authorised by:
Department of Environment and Primary Industries
1 Spring Street
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