SIMPLE things like retaining stubble or even putting out nitrogen fertiliser on wheat crops are taken for granted in today’s farming systems.
But there was a time, not that long ago in relative terms, when the no-till and minimum till practices used by close to 90 per cent of Australian croppers in some fashion was a revolutionary, risky idea.
One of the first proponents of no-till practices in the country was agronomist Peter Ridge, who worked in the Wimmera region as one of the first private agronomists in the mid 1980s.
Following a stint with the Victorian Department of Agriculture, Mr Ridge said one of his major focuses when he went out on his own was to work to improve water use efficiency.
“We used to use neutron probes to monitor soil moisture reserves and it was pretty clear there were better results in systems incorporating stubble retention,” Mr Ridge, who now lives in Corowa, NSW, said.
“This field research backed up work we had done at the Department that pointed that stubble retention also retained moisture.
“It was worth an extra 50-60 millimetres a year compared to traditional cultivated paddocks.”
Mr Ridge said the initial work in Australia followed research out of North America showing good promise with no-till systems.
There was also a lot of work being done in Queensland, where researchers were primarily looking at managing high volumes of water during big rainfall events by having standing crop residue.
But while researchers were optimistic of its benefits, there had only been very sporadic uptake by Australia farmers.
Big dry was catalyst
Mr Ridge said the catalyst for change was the 1982 drought and the massive dust storms of early 1983.
“People saw things had to change if they weren’t to keep seeing their farm blow away.”
But it was not just environmental concerns, Mr Ridge said farmers were motivated by a chance to generate greater income.
“With the old cropping system, they were limited in how often they could crop, and with the soaring interest rates in the 80s, they wanted to make some money in a hurry and the best way to do this was to get more crops in.”
One of Mr Ridge’s earliest clients was St Arnaud district farmer Allen Postlethwaite, Victoria.
“We had a mixed enterprise, but when my wife Yvonne, who has a business management background, went through the books, she found cropping was making 90 per cent of the money.
“She said we needed to do more cropping and to do this we had to move away from cultivation and change our rotations to allow us to get more crop in each year.
“The wind erosion factor was just too great in a conventional system so we moved across to no-till and have never looked back.”
Mr Ridge said one of the star performers of the early years of no-till was pulse crops.
“We had some great legume years so crops such as faba beans and field peas, and in particular chickpeas, did very well.”
Mr Postlethwaite said adding chickpeas to the rotation was a revelation.
“We found we could grow as good a wheat crop or better the following year as we could with a fallow and we got the chickpea crop as well.”
Mr Ridge said the opportunities to sow earlier and to have stubble acting as a trellis for low-growing legumes allowed growers the chance to diversify.
“It was during the 80s that we really saw crops like canola and the pulses come into favour.
“People were planting chickpeas into canola stubble and getting phenomenal results, chickpeas were very reliable until we saw ascochyta blight in the 90s.”
He said initially it was easy to control weeds in a no-till system with herbicide.
“We had a full suite of herbicides, and there were no issues with resistance.
“Even some like (group A herbicide) Hoe Grass was a wonder chemical, it just cleaned all the grasses up straight away.”
Mr Ridge said it was not until the early 1990s that problems with herbicide resistance became apparent.
“We saw some problems there and people have had to learn to manage it within their system as best as they can.”
Into the future, Mr Ridge said he thought continuous cropping, no-till systems could work, even with increasing pressure on herbicide rotations.
“I think farmers are just going to have to be smarter about it, we may need to see more hay crops or brown and green manure crops in order to cut down weed seed banks.”
Mr Postlethwaite said herbicide resistance had to be monitored, but at present it was manageable.
“We do a bit of row cropping which allows us to use a shielded sprayer to sprayer between the rows and that has been very good in ensuring herbicides remain effective.
“There were initial problems with selective herbicides, then we haven’t seen much until recently, where we have started to see some issues with glyphosate resistance, which is a big concern, but something we should be able to manage with chemical rotations.”
Early form of controlled traffic
In terms of machinery, seeding equipment used similar principles to today, but farmers did not have the advantage of guidance to allow them to precision plant.
However, Mr Postlethwaite said on his property, which he ran with sons Neale and Trevor, a primitive form of controlled traffic was in place since the 1980s.
“We went no-till and within a couple of years we were working on something quite like controlled traffic.
“By 1985 or 1986 we were leaving a mark with the seeder that the boom spray could follow.
“It was more for operational purposes than the benefits of controlled traffic as we know it today, it improved visibility.”
Mr Ridge said most of his clients moved out to 13-inch (33-centimetre) spacings to allow them to sow through the residue.
“The operational benefits of being able to get through the trash more than made up for any small yield losses.”
He said farmers had some benefits immediately from converting to no-till, such as the ability to dry sow and continuous crop, while others took more time.
“There are obviously big improvements to soil structure, but it takes time.
“It took a couple of years, but then we definitely saw softer soils with better water infiltration.”
He said initial scepticism to no-till centred on the conventional wisdom of the time that you could not grow a crop without some form of cultivation.
But he said growers soon saw the value.
And Mr Ridge said growers could get the vast majority of that value without having to embrace a full zero-till, controlled traffic system.
“I’m not a purist, I take the point of view that so long as you keep some stubble and reduce disturbance where you can you will pick up 90 per cent of the benefits without being extreme, it is very difficult to be absolute with anything in the paddock.”
Into the future, both men believe precision agriculture will be the avenue for productivity gains.
“Things have certainly plateaued a bit with no-till, but I think there are gains to be made from precision agriculture,” Mr Postlethwaite said.
“We will be able to be more efficient with our inputs through things like variable rate application of fertiliser and the correct seeding rates for the soil type.”
He said he could also see better use being made from data.
“We’ve got extensive yield mapping records, we hope to see them matched up to other factors to figure out what is causing that yield variation within the paddock and manage it accordingly.”
Mr Ridge said the ability to affordably embrace concepts such as inter-row sowing and spraying was a boon for growers.
“GPS technology down to 2-centimetre accuracy has become very cheap and that can only be good for growers.”
Mr Postlethwaite said big advances had been made in the past 30 years.
“When we first started working with Peter, the official line was that you could not put your nitrogen fertiliser out on a wheat crop, it was a product better suited to higher value crops or to the pasture phase, so things have certainly changed a lot.”