Oats underpin mixed-farm management
GroundCover™ Issue: 113 | Author: Nicole Baxter
A farming family from Condobolin in central New South Wales is endeavoring to turn every drop of rain into grain, with opportunity oat crops providing management flexibility
Oats are sometimes the forgotten crop in today’s farming systems but for New South Wales central-west grower Graham McDonald they “tick all the boxes”.
On the 3300 hectares across two blocks Graham farms with his wife Marjorie, son James, brother David and David’s wife Jennifer, 16 kilometres north and 30km north-west of Condobolin, Yarran oats are sown for many reasons:
- as a cash crop;
- to establish lucerne and medic pastures;
- to feed sheep in dry seasons;
- to increase ground cover;
- to increase water infiltration; and
- to break disease cycles.
The McDonald family runs a crop rotation that generally comprises four to five years of cereals, followed by a four to five-year pasture phase of lucerne and medics. Canola or Monola®* is sown as an opportunity crop if the price is high and starting soil moisture is adequate.
Oats are sown as a cover crop to establish new lucerne and medic pastures, and then harvested as a cash crop to help cover the cost of establishing the pasture. From the end of March to early April this year, Graham sowed 800ha of oats at 10 kilograms/ha as a low-density cover crop for lucerne and medic pasture.
By the fourth year, if the pasture becomes thin and the paddock becomes hard and compacted, oats are drilled into the pasture to improve ground cover and increase water infiltration in readiness for the return of the wheat phase. This oat crop is also then harvested as an additional cash crop if the season has been favourable.
GRDC-supported water use efficiency trials by CSIRO’s Dr James Hunt have shown that reduced water infiltration from grazing was due to the removal of cover rather than compaction by hooves.
In early March 2013, the McDonalds drilled oats (as an opportunity crop and to boost ground cover) into lucerne and medic pasture at 30kg/ha with 25kg/ha of monoammonium phosphate using knife points and press wheels.
Graham says there was plenty of feed available in 2013 and they decided not to graze sheep on the oats, or spray them out, but allowed the crop to mature to harvest.
By October 2013, Graham was confident the oats would achieve a gross margin of $250/ha. “They looked so good,” he recalls.
When harvest arrived this opportunity crop of Yarran oats yielded 1.85 tonnes/ha and the dry conditions in northern NSW meant demand for feed grain was high, so a large portion of the oats were sold to a local miller for $250/t.
Another benefit of oats is they provide a disease break before swinging paddocks back into wheat.
The only downside of not spraying the oats to prevent seed set was an explosion in the barley grass population, which meant the oats paddock had to be left out of wheat this year.
Sheep grazed the paddock until August when it was sprayed before seed set in preparation for a wheat crop in 2015.
Graham expects he will have to spray the paddock twice in summer to ensure all weeds are controlled before sowing.
Summer weed control is critical to the family’s crop management. A study by Dr Hunt, as part of the GRDC’s National WUE initiative, showed that up to 72 per cent of wheat yield in central NSW can be attributed to summer rainfall.
John Small, extension agronomist with the grower group Central West Farming Systems (CWFS), says anyone who fails to control summer weeds within two weeks of a rainfall event loses very valuable stores of moisture and nitrogen from the soil.
“For every millimetre of soil water transpired by summer weeds, the subsequent crop loses 0.7kg of nitrogen, equivalent to 1.5kg/ha of urea at 100 per cent application efficiency,” he says. “That means losing 20mm of soil water through weeds is losing 28kg/ha of urea.”
Graham says the massive amount of nitrogen lost from the soil, which was confirmed in collaborative trials by the NSW Department of Primary Industries and CWFS, was surprising.
“We thought we were losing a small amount of nitrogen by allowing sheep to graze weedy paddocks for a bit longer, but didn’t realise how much,” he says.
Now, Graham says the family is spraying to keep the fallows much cleaner than they did in the past in a bid to turn every available drop of rain into grain.
Another outcome of the national WUE project was the value of sowing long-season wheat varieties early.
Graham recalls sowing Sunbrook wheat “years ago” around 16 April and says it was always their highest-yielding crop.
However, until LongReach Lancer was released this year, which he is bulking up, there were no varieties available for sowing in his area much before Anzac Day (25 April).
Frost can be an issue some years: “A couple of years ago we started sowing on 2 May and were smashed by an unusually late frost, losing 30 per cent of our EGA Gregory yield,” he says. “So we hung back a bit when we probably shouldn’t have.”
Graham says one of the biggest challenges facing the cropping side of the business is the narrowing margins and the increasing cost of production. To offset increasing costs, the McDonalds are considering expanding their landholding to run more sheep as a risk management measure.
The other challenge he and his family are working hard to manage is a lack of reliable seasonal labour. In meeting that challenge the McDonalds are trying to set up the business with enough machinery so they can complete cropping tasks themselves in a timely manner.
Going forward, Graham is keen to increase his nitrogen inputs where necessary and has been inspired by GRDC research on acidity management to look at spending more on lime.
“We certainly have an acidity problem because our pH is down to 4.5 (calcium chloride), so we can’t keep cropping without addressing that,” he says.
02 6896 5306,
* Monola® is a form of canola. It was developed using conventional plant breeding and has a lower percentage of saturated and trans fats in its oil than canola. Another difference is that Monola® oil remains stable during prolonged use at high temperatures, making it ideal for end uses such as fast-food frying.
GRDC Project Code CWFS0013, FLR00005
Region South, North