The drainage of dairy pasture is the simplest way to boost utilisation rates.
When intensive dairying occurs in the high rainfall zone on heavy soils, the inevitable pasture loss due to pugging and poor utilisation erodes the profitability of the enterprise. Cow health suffers, pastures are damaged, and additional feedstuffs need to be included in the ration to make up the shortfall in pasture consumption. Open drain networks and ‘hump and hollow’ systems, go part of the way to control waterlogging, but come at the cost of disruption to movement around the farm and have limited effect unless they are impractically deep.
Sub-surface drainage controls the waterlogging in the plant root zone and allows the grazing enterprise to continue un-hindered. Existing creeks and watercourses can be used as outfalls or in flat landscapes, a network of strategically placed open drains can service the drainage need. These drains rarely operate on just one farm and often need to be designed ‘across boundaries’ in consultation with neighbours. Heavy clay soils require mole drainage in addition to the network of pipes and gravel. Many farmers report gains of an additional 2 tonnes DM/hectare utilised and payback periods of less than 3 years.
DPI Pasture Calculator
In order to evaluate the benefits of a sub-surface drainage system on your farm a useful tool is available from the Department of Primary Industries Victoria.
This free to download program will help calculate pasture Consumption and Feed Conversion Efficiency for your farm and it will identify current levels of home grown pasture production and utilisation percentage.Armed with this information you will be able to identify where your pasture production sits compared the potential for the district. It is the economic value of this marginal production that will determine the payback period for your land drainage investment.
Download the program at www.dpi.vic.gov.au/agriculture/dairy/pastures-management/calculator