With a milking platform of just 100 ha and a spring peak of around 530 cows, the Murphy family, including parents Kevin and Jan, has invested heavily in additional land to support a cut-and-carry system.
Management and fodder growth have changed from a grazing system to include growing about 161 ha of cereal crops annually, in particular corn, which has been part of the rotation for the past five years.
Corn is grown under pivot on an outblock purchased by Mr Murphy and, for the next three years, management, growth and irrigation will be put under the microscope as part of a Murray Dairy project — Smarter Irrigation for Profit 2.
“We are looking to grow as much corn as we possibly can and get the most efficiency out of the water we have,” he said.
“To have a study done using our own data will be extremely helpful when it comes to looking at our future management.”
Under normal seasonal conditions about 30 ha of corn is harvested but this season, due to high water prices, the area was reduced to 16 ha.
“There is nothing like corn to produce bulk feed over a short period,” Mr Murhpy said.
“This year we grew a 26 tonne/ha crop in four months, and we will follow with an 8 to 10 tonne/ha Wrangler wheat crop for young stock feed.”
He said corn was an expensive crop to sow at $500/ha, so getting it right from the start was paramount.
“We used 7.7 Ml/ha including pre-irrigation on a 167 mm rainfall season.”
The crop was planted on November 15 and harvested on March 28. Based on a temporary water price of $400/Ml, the corn cost $265/tonne in the pit.
Through a drought infrastructure grant, Mr Murphy bought two soil moisture meters which have gone on to become a valuable asset and an important part of management.
The combination of pivots and moisture meters has given Mr Murphy confidence to grow corn in an expensive water year, although there is a limit to the price he can pay. And like everyone else, he would much prefer a sustainable and realistic temporary water price.
“My idea of timing of irrigation has been different to the meters and we have used more allocation this year, but our yield has improved from 19 tonne/ha last year to 26 tonne/ha.”
He attributes the increased yield to accurate moisture data from the meters, but also to a change in contractor.
The one pass ‘strip till’ sowing including fertiliser has been a huge advantage, resulting in reduced weed burden and better yields.
Mr Murphy said growing corn and cereal crops supported a cut-and-carry system well.
This autumn they have sown 30 ha of vetch and 42 ha of Wrangler wheat, along with the 16 ha of corn last year.
“Once you are set up this system works really well,” he said.
“I think we now have a sustainable farming model moving forward and I am confident in our future.”
The milking platform has 10 ha of perennial pasture which might be considered a waste of water by some, but Mr Murphy said it still had a place, especially if the season comes in wet over winter.
He said the Smarter Irrigation for Profit 2 project had real value for northern Victorian irrigators.
“A lot of pasture projects are based down south and the data collected from this one will be relevant to so many farmers, especially considering many have changed their management to grow cereals to suit availability of water.”
Murray Dairy site co-ordinator Lisa Menhenett said the research would reflect local needs.
“In northern Victoria, many irrigation systems are moving to annual rye-grass, cereals and summer cropping for silage,” she said.
“The site in northern Victoria is looking specifically at a surface-irrigated double-cropping scenario with maize followed by a winter cereal.
“We hope to address the lack of regional information on these scenarios.”
