by Nicola Bell, The Weekly Times
STUART McDonald's benchmarking data has identified the negative impact on profit rotating between cropping and pasture has on a paddock.
And it is because of this he is moving toward continuous cropping along with livestock production on his property at Canowindra in the New South Wales central west.
Keen to find out what options are out there and what will work in his environment, Stuart has been awarded a 2018 Nuffield scholarship to research how continuous grain cropping with the aid of livestock can be sustained in a high-rainfall environment.
Stuart, and his wife Ellen, operate a 1363ha mixed-farming enterprise, which has been in the McDonald family since 1888.
Stuart is the fourth-generation of his family on the farm. He had taught agriculture at high school but returned home in 1998 and, through a well thought-out succession plan, progressed from employee to major partner to running the business.
The operation comprises about 1050ha of crop - mostly wheat and canola as well as lupins and chickpeas - alongside a self-replacing merino flock of about 1300 ewes and 35 stud Illawarra dairy cows.
"About 75 per cent of the property is cropped as we move in to a continuous cropping program,” he said.
STUART has been part of a local business management group for the past 14 years and he said the benchmarking data showed rotating in and out between crop and pasture resulted in under-performing transition crops, which had an impact on their gross margin.
"We have had some paddocks in continuous crop for 20 years and the analysis shows this keeps the returns more consistent,” Stuart said.
Stuart acknowledges there is a compromise on soil biodiversity, but this could be built up with high inputs.
"Everything comes at a cost, and our aim is to keep returns consistent over the long term,” he said.
The McDonalds' property receives an average of 650mm of rain a year, which is non-seasonal. Stuart said benchmarking data also showed their water-use efficiency was better in drier years than in higher rainfall years.
"There are a number of reasons for that probably, but we realised it was important to use every bit of rain that falls on the place,” Stuart said.
The McDonalds work on a three-year crop rotation, planting two years of wheat and then one year of canola.
"We try to vary varieties of wheat and use a longer term and short-term wheat to reduce pathogen potential and give the paddock a bit of a rest.”
The long-term yield averages are about four tonnes/ha for wheat and 1.8 tonnes/ha for canola.
Last year the McDonalds also planted a paddock of chick peas off the back of the lower wheat prices and Stuart said they could have a place in the rotation in the future. Lupins are also grown for supplementary feeding sheep.
FOR the past two years the McDonalds have been collecting yield mapping data and will look at how they can use this through variable-rate sowing and spraying.
They have also been part of a five year carbon sequestration program through the Local Land Services which involved using biosolids, to try to improve soil carbon.
"We are waiting for the data to come back to see what benefits it had, but I think the paddocks seem to have hung on better and yielded as well as any others.”
Meanwhile, with the self-replacing Merino flock, Stuart said they moved away from breeding their own rams about five years ago and now purchased rams locally to simplify the system a little.
And on the back of improved returns for sheep and wool Stuart said he was looking to manage the 1300 Merino sheep more closely.
"We are in a prime lamb-dominated area and I have been watching what others are doing with their lambing percentages and I think we have room to improve.” The McDonalds' lambing percentage is solid at 100-110 per cent, but Stuart said they hoped to increase it further by improving ewe performance at key times.
"We have employed a nutritionist to help us look at what feed such as lupins or wheat stubble we have on hand and to develop a supplementary feed system to raise the condition score of the ewes and to feed lambs at weaning.”
WITH an average fibre diameter of 19-20 microns for ewes and 17-18 for lambs, shearing is every eight months.
"We moved to shearing three times every two years about five years ago for cash flow. The sheep seem to be thriving with less wool and we don't have to crutch in between.”
"We are aiming to get a 75mm staple length, or longer, and if we achieve this we get a similar per-kilogram price for the wool.”
For his Nuffield scholarship study, Stuart will go on his first trip in March and said he is looking forward to seeing how sheep and cropping can be complementary to help enhance whole farm profitability.
"I am hoping to find there is scope to vary the crops we grow and to improve the soil asset.
"Continuous cropping isn't common in our mixed farming, high rainfall environment and the Nuffield scholarship will give me the opportunity to address the current knowledge gap and to then apply what I learn on-farm.”
Something his initial research has already led to is trialling cover-cropping.
Stuart said they planted a couple of paddocks of multi-species cover-crop in to last year's wheat and canola stubble to see its effect on the soil. The crop includes corn, sorghum, vetch, sunflowers, and field peas and was lightly sown.
"The aim with cover-cropping is to have as many species growing in the soil when the crop isn't in, so you always have a green plant and living root in the soil to add diversity, microbiology and help build organic matter. From what I have seen other people get really good results, so if it works this could be a good addition to the continuous cropping system.”