Water maximised for year-round crops

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Photo of Craig Reynolds

By Brad Collis

Water is a resource; be it an irrigation allocation that has to be paid for or free rainfall. Astutely balancing these two sources is the basis on which northern Victorian grower Craig Reynolds is intensifying his cropping to maximise year-round production.

[Photo (left): by Brad Collis: Congupna farmer Craig Reynolds: "We"re actually working towards being able to harvest one crop and sow the next in the same day."]

Mr Reynolds" 390-hectare enterprise at Congupna used to be based around his 800-megalitre water allocation for summer irrigation. The winter was a period of fallow. However, he became increasingly convinced that the 480-millimetre average winter rainfall was a resource that needed to be more directly utilised.

"Also, a fallow paddock only wants to grow weeds. We want our paddocks at all times to be growing something harvestable," he says.

This meant developing a strategy for continuous cropping which began in 2000 and was taken a step further in 2003 with the introduction of tramlines and controlled traffic.

"In winter we now plant the whole farm and in summer between one-third and onehalf," he says. "This gives us an overall cropping intensity of 150 per cent."

Winter crop rotations, on soils that range from loam to clay, are clover hay over onethird of the area, and the rest rotations of wheat, barley, faba beans, maize and oaten hay. "Hay is in the mix to allow me to doublecrop, and it is as profitable as wheat," he says.

The clover also halves the amount of urea needed in the following maize crop.

"The ideal rotation for us is soybean, clover hay, maize and wheat, with the option of a faba bean crop sown into the maize stubble."

Mr Reynolds says the hay is cleared off early in November to make way for summer crops of soybean (for the human foods market) and maize (for the stockfeed market).

He says that while it takes five megalitres of water per hectare to grow a summer crop, the irrigated maize can yield a handy 15 tonnes per hectare.

"Essentially, if we are harvesting 6t/ha of clover hay and say 14t of maize, that"s 20t/ha. Even if this is only happening on a third of the farm it"s a very profitable use of the land."

To handle dense stubble in a continuous cropping regime, Mr Reynolds has introduced controlled traffic, with the equipment set up for three-metre rows. "Controlled traffic gave us the opportunity to start afresh with a whole new system," he says.

To spread the capital cost he teamed with a neighbour who has a similarsized farm and similar ideals. "He owns the seeder and sprayer and I bought the header and hay equipment and we contract to each other," he says.

Mr Reynolds and his neighbour, Ross Heywood, built their own planter designed to inter-row sow with auto-steer (a 2cm Autofarm) to navigate heavy stubble. In 2005 Mr Reynolds received a National Landcare Program Natural Resource Innovation Grant to further develop the planter and modify the header to manage the straw and chaff.

"A Redekop MAV Chopper Spreader was fitted to the header and has worked well.

"We try to keep the stubble intact, complete with roots, to hold the soil together when we flood-irrigate."

Mr Reynolds says that managing the stubble this way has significantly increased the soil"s water-retention capacity: "We used to irrigate the soybeans every four days. You could irrigate in the morning and the soil would be dry again by late afternoon. Now we only have to irrigate every 10 to 14 days."

He says the improved soil structure not only makes the irrigation water go further, but also increases the soil"s ability to store rainfall for much longer. "We"ve found that keeping the stubble in the ground is as good as a pasture phase."

Mr Reynolds says the equipment setup on the two farms still needs some work, particularly the machinery"s capacity to work wet soil.

"We"re actually working towards being able to harvest one crop and sow the next in the same day to make the most of our short harvest and planting windows and soil moisture."

More information: Craig Reynolds, reynolds@mcmedia.com.au