Maize has been grown over centuries and has been proven a beneficial grain for humans as well as cattle. With a strong return on the investment for labour, water and other costs, this crop is popular for inclusion in the dairy ration as chopped silage.
It requires special machinery to harvest and cut the plants into smaller portions to create a manageable material. The development of growing maize and other summer forages in northern Victoria came about as the crops offered better use of irrigation water and could be fed more easily to the herd as farms moved to using feedpads rather than free-range grazing of summer pastures.
Changes to irrigation water allocations have seen an evolution in the northern Victorian irrigation district. Where herds of cows once roamed and grazed large tracts of green pastures, these days most dairy farms now partially confine their herds to set areas and bring the feed to the herds.
Dairyfarmer numbers have reduced over time, and those remaining are working hard and milking more cows to maintain a milk supply that will retain manufacturers in the region.
Bernice and Scott Lumsden farm near Leitchville, Vic, and grow maize to harvest the whole plant for silage. Contractors are used to do this, and a portion of their Torrumbarry irrigation water entitlement is used to grow the crop.
The couple has done so for some years now. "We found it a worthwhile crop to include in our mix especially as we feed out a large portion of our feed on the feedpad," Mr Lumsden said.
The Lumsdens are part of a large family enterprise with Mrs Lumsden's parents, Noelene and John Smith. The Lumsdens oversee the business and milk 700-800 cows in a 80-unit rotary. The farm has a large covered feedpad, capable of handling 1200 cows.
The dairy portion is a 600-hectare holding split by the upgraded main channel for the Torrumbarry irrigation system and the Murray Valley Highway. The channel is crossed with a bridge and the highway by an underpass within 100 metres of each other.
The business employs three permanent labour units and seasonal backpackers.
The Lumsdens became interested in maize via their consultant and nutritionist. On an Alta Genetics trip to the United States, they viewed the process and benefits of feeding corn to dairy cows. During the trip, they were able to concentrate on learning about maize as a supplement in their feeding system.
Mr Lumsden said they were impressed with the quality and appearance of the mostly corn-fed cows in the US. It was a next logical step to start growing maize on their property, as they already had in place the feeding system of wagon and feedpad.
They have grown maize for four years. They work on a principle of three years of maize on the same area and then a new area is used, with the previous land rejuvenated with an alternate crop.
The maize is sown by precision drilling into a bare seedbed in spring on flood irrigation bays. Nitrogen is applied at 350 kilograms/ha of "green" urea and disced into 150mm, with the area then multi-disced with 240kg/ha di-ammonium phosphate (DAP) and then another 400kg urea applied.
In the first season, sowing density was 90,000 seeds/ha. Since then, this has fluctuated between 90,000 and 100,000 grains/ha. Mr Lumsden said this year they would be likely to sow at 92,000 seeds/ha.
The precision drill is accurate and allows the sowing rate to be calculated as all seed bags are seed numbered.
Mr Lumsden keeps accurate records, with his whiteboard and
diary all show excellent recording of facts related to growing and feeding the cows.
Water use on the maize is 7.5 megalitres/ha. The growing period is about 124 days to harvest, which occurs at milk line four in the grain in the crop. The milk line is defined by shelling individual grains with the fingers and then viewing the milk line and getting the indication of the starch content of the grain to determine harvesting.
Contractors harvest the three-metre-high standing crop by cutting and chopping into 25-30mm long portions. This is then put into earth-walled bunkers on top of the ground and covered by multilayered sheeting.
Mr Lumsden said the new orange sheeting had improved the storage since they started this type of operation. The yields have varied but last season 3000 tonnes of green matter with a 34 per cent dry matter content was put into the pits from 40ha of crop.
Mr Lumsden said this was a worthwhile return on investment and he would consider continuing with the process.
"We can't cheat on the process and there is a defined recipe to grow a maize crop," he said.
He quoted a neighbour who once advised him "you cannot be arrogant growing maize".
The process is not always straightforward. In the first three years, the maize was grown on bays with good reuse water collection. It made for more efficient water use. The next plot did not have this feature so Mr Lumsden decided to grow the maize in only three-quarters of the bay with sorghum grown at the ends of the bays as a sacrifice crop if overwatering occurred.
However, he conceded that during the process, nature decided to water the sorghum also and issues arose with water use. Birds, too, have created problems, with cockatoos and corellas being a nuisance but Mr Lumsden said the crows were the worst. These would not be scared off, especially at seeding time.
The crop was also affected by excessive November and December rainfall last year. When growing maize again, a close watch will be kept on weather forecasts, slightly higher fertiliser rates will be used and seeding rates and pest control will be more rigorously implemented.
Mr Lumsden said there were also issues with the outside boundaries of the crop maturing earlier than the middle of the rows due to sunlight and air circulation. He feels that spacing between rows and spacing between seeds in the rows also play a part, and this year will use 25-centimetre row spacing with probably the same in the seed placings.
The Lumsdens' priority is to fully feed their herd. Mrs Lumsden said: "At the moment we're feeding silage in the 5.75-tonne capacity Keenan wagon with 2 tonnes of maize, 1 tonne of hay, 1.5 tonnes of lucerne silage, 0.25 tonne of grain and 1 tonne (1000 litres) of water added together.
"We are also feeding the cows a grain and canola ration, including a buffer, on the milking platform." The amount is computer monitored and varies per individual cows, depending on the stage of lactation, production and condition score.Their preference would be to feed on the feedpad and provide the cows with some green pasture all year round. However, at the moment there are times during the season when the herd is on pasture full time or on mixed rations full time. Their challenge is to find that balance.
The facilities are excellent with a solid roofed feedpad and good access to all parts of the farm. So some time into the future the ideal will be achieved.D