Dairy Effluent: Overview of Effluent Management in the South-West
Updated: September 2007
Note Number: AG0420
ISSN 1329-8062
Hayden Ballinger, Colac
South West Victoria is a major contributor to the Victorian dairy industry with about 31% of the states milk production. Large variations in landscape and farm mean that a range of systems are used to manage effluent. As dairy farming expands and intensifies, suitable management of dairy effluent is encouraged.
A diverse region
The south west region covers a spectrum of farms. Ranging from the rolling hills of the Otway's, to the flat inland plains. From the sandy coastal pastures to the heavy cracking clays. This diversity means that designing an effluent system that suits both the farmer and the land is so very important.
An expanding industry
The dairy industry in the region is very dynamic. Herd size has been steadily increasing over the past 50 years (Fig 1).
Figure 1 shows how herd size has increased over the last 30 years.
As a result of increasing herd size, dairies are being enlarged, laneways have to be widened and water supplies improved. In many cases these improvements take priority and many effluent management systems have not kept pace with the increase in herd size.
As the number of cows being milked on farms is modified to cope as has been evident with the EPA effluent auditing program across various catchments.
The law states that all effluent must be contained and managed on farm in a manner that precludes the pollution of both ground and surface waters. The EPA continues to have an active presence in the region ensuring that this vitally important.
Suitable effluent systems
We have seen the progression of farm effluent systems from the basic pile of manure alongside the old walk through dairy in the 50's to the now common two pond system on many farms which date back as far as the 70's.
However, a good effluent system requires more than just having suitable infrastructure (eg ponds) to contain the management of the effluent in a sustainable way.
Infrastructure
Suitable effluent system infrastructure to contain effluent can either be pond/s or a direct application system. Due to high seasonal rainfall and generally heavy soils, the preferred option is usually a pond system. These systems include an anaerobic digestion or solid settling pond in conjunction with a storage pond which provides the flexibility to store the effluent over the winter. These systems promote an ease of application through sprinklers and an opportunity to recycle for yard cleaning. However, there are areas where soil types are free draining and direct application of effluent via sprinklers and irrigators may be west have now got some type of infrastructure; however the ongoing management of the system remains the most challenging
Management
In the past the emphasis was largely placed on getting a pond in and containing the effluent; now the challenge lies with getting the management to match.
Even the best designed effluent systems have failed in the past due to inadequate and adhoc management. Ongoing
- Regular pond emptying
- Periodically sampling to determine actual nutrient values.
- Maintenance of banks and surrounding areas
- Pump scheduled maintenance
- Desludging and decrusting
- Weed spraying around ponds
To have ongoing effluent management it's paramount to understand the farming system and implement suitable management. For example; if time is a farmer's top priority then a contractor may be his most suitable management option. On the other hand if labour is the priority then an automated irrigation system is more practical than one that requires daily shifting. Once the options are discussed and the most suitable one chosen then it's a matter of getting out and doing it. Scientists and farmers alike have demonstrated beyond doubt that effluent is a valuable resource that can grow some bumper crops. So don't simply manage the effluent, utilize it and watch it pay dividends.
The south west has a range of good contractors who construct and clean out ponds as well as design and install effluent irrigation systems. DPI staff is also available to provide Effluent Management Plans which cover all facets of effluent system design and management.
Further information
Kyabram – (03) 5852 0500
Ellinbank – (03) 5624 2222
Colac – (03) 5233 5533
Kerang- (03) 5452 1266
Warrnambool – (03) 5561 9946
Acknowledgments
The original Agnote material was provided by David Hopkins 1995, Colac.
The advice provided in this publication is intended as a source of information only. Always read the label before using any of the products mentioned. wholly appropriate for your particular purposes and therefore disclaims all liability for any error, loss or other consequence which may arise from you relying on any information in this publication.
