Fodder crop givespoor soils a value
GroundCover™ Issue: 56
Alan and Joy Heitman"s farm "Arena" in south Mingenew, WA is one of the focus farms for the Mingenew-Irwin Group"s Grain and Graze project. Tracy Gillam reports on the family"s efforts to develop new options for poor soils
[Photos by Tracy Gillam: Looking for new solutions: Alan Heitman in his experimental paddock, which contains a range of perennial species including saltbush and tagasaste.]
"We"re on the adventure trail," declares Alan Heitman as he drives around his sandplain farm south of Mingenew, about 360 kilometres north of Perth. Alan is explaining the family"s move into grazing as part of a diversified cropping regime designed to make better use of previously unproductive soils.
Alan and Joy Heitman farm with their son and daughter-in-law, Donald and Julie. Alan and Joy manage the livestock enterprise on their 8000 hectare farm, which is twothirds cropping and one-third pasture.
Traditionally, Joy and Alan have achieved very little productivity from their deep white sands, gravelly ridges or their sand over pink clay.
"The soil fertility of the deep sands and sand over pink clay was totally non-productive for cropping," Alan explains. "So we looked for other sandplain options and found that tagasaste was well suited to this soil type. And then, once we had found something to grow on the soil, we needed something to eat the tagasaste - hence the move into cattle."
The Heitmans were also inspired by a similar move by another grower, Craig Forsyth at Irwin, and saw that the system was working well on his poor sands.
The cattle were introduced six years ago, beginning with a herd of 36 cows. Today Alan is running about 600 cattle over tagasaste. The cattle enterprise is predominantly run on tagasaste with some cattle finished off on stubbles: "For example, we have the steers on tagasaste until after harvest and then on to the stubble. The steers are topped off on barley stubble for about one month before being sold."
He says that having the tagasaste takes the pressure off the stubble needing to carry livestock all through the summer: "It gives us more flexibility in our on-farm feed mix."
The tagasaste is grown on sands unsuited to cropping. These were originally pasture paddocks with very poor productivity. Alan recalls when they were not able to maintain a stocking rate of even one ewe per hectare. The soil is very poor, deep white sand.
"The tagasaste paddocks are now being reduced from 40ha to 20ha, as we feel that this will lead to better feed utilisation," he says. "The paddocks are being divided using single-line electric fencing to control the 100 to 120 cows in the tagasaste area. The tagasaste is then grazed hard until its colour changes to a "dull" green - indicating that all new, fresh growth has been grazed."
Alan rotationally grazes the cattle through the tagasaste relying on the "look" of the tagasaste stand rather than grazing for a set period of time. The grass between the tagasaste rows also acts as a further feed source, along with mineral licks.
In another bid to better match land use with soil type, Alan has a small fenced-off area devoted to experimenting with new varieties. This year he is trialling Old Man Saltbush on sandplain soils and weeping tagasaste. Unfortunately the trial area was grazed heavily by stock after a gate was left open.
However, this accident has led to some interesting observations. "Although the Old Man Saltbush was eaten to ground level, much of it has survived. It makes me wonder whether Old Man Saltbush is a possible alternative to tagasaste on sandplain soil."
Perennial grasses are also becoming part of the Heitmans" push for more appropriate land use. About 100ha of sand over pink clay has been sown to a perennial grasses mix consisting of Gatton, Rhodes, Panic and Setaria. The perennial grasses were sown in 2002, with long narrow points and trailing press wheels. Alan plans to divide the 100ha into 25ha lots, with a central watering hub. This will allow for rotational grazing.
Alan and Joy now plan to continue developing perennial pastures on their poorer soils, which will also help reduce the grazing burden on stubble.
For the moment, all the tagasaste paddocks will be fixed at 20ha: "We"re not really sure where we will go once we have 20ha paddocks - but that"s the beauty of it.
"Once we have 20ha tagasaste paddocks, we may find that we can go smaller again. The main focus is to trial new ideas and new species that are suited to our soil type and environment," Alan says.
GRDC Research Code LWR23
For more information: Alan Heitman, 08 9955 8044