WESTERN Australian grower Mic Fels is hosting a five-year trial on his family’s farm in the Esperance region which he hopes will provide a guide as to how to build soil health
Being conducted for Carbon Ag by independent research company, South East Agronomy Research, it is investigating the banding of its C33 carbon compost product at seeding, as well as high concentrate liquid phosphorus and potassium fertiliser, PowerPK.
Mr Fels, who is also the WA Farmers grains president, said “snake oils” and remedies had been promoted previously without demonstrating replicated data and had not survived.
“When you look at the total tonnes of carbon per hectare being applied, it’s tiny and our scientific
instinct is to say that can’t increase soil carbon.”
The Fels crop 6000 hectares at Wittenoom Hills, including leased land, to cereals, canola and some
lupins over soils ranging from coastal sandplain through to traditional mallee country with sandy
tops, as well as some heavy clay areas.
“Building carbon is incredibly hard to do in agricultural soils…so I’ll keep an open mind with the opportunity to test it in this trial and see in five years.’’
Test for duplex soil
The trial has been established on a consistent, shallow duplex soil type comprising a sandy layer over a dome clay base, and was one of the drier areas of the wheatbelt last season, despite waterlogged conditions nearer to the coast.
Banded applications of the C33 carbon product and PowerPK liquid fertiliser are being compared with traditional seeding applications supplying around 15 kilograms per hectare of phosphorus and potassium and 5kg/ha of nitrogen, with another 100kg/ha of nitrogen topdressed after seeding.
The trial is also investigating substituting half of the traditional seeding application with the PowerPK, which, although supplies less total volume of phosphorus and potassium, matched the similar yields achieved by all treatments across the site last year.
Mr Fels said the C33 and PowerPK treatments looked good in the trial last season, with noticeably improved plant health and vigour.
“If I was set up for liquids at seeding, I would certainly be doing some strips with the PowerPK product, but my air cart is not.
“But we have the trial here, so I will definitely be looking at that, and, with people getting some good results using soil wetters at sowing as well, it’s not to say we won’t consider moving to using liquids again in four to five years.’’
Mr Fels said he would keep an eye on the carbon product in the trial over time, and if any product showed an economic or other benefit that can be quantified, it would be phased in.
“I’m not here to build soil carbon as an end in itself – the point is building the resilience and health of the soil so we can then grow better crops, which is also more sustainable and profitable.
“We like to think we are a scientific industry and understand everything.
“I think when it comes to soil health, we know almost nothing.”
Trial and error needed
Mr Fels said some trial and error was required to see if triggers could improve that process of carbon sequestration.
“That’s the buzz word, but we’re really about just building soil health.”
He said the deliberate strategy of using narrow rows, higher biomass varieties and concentrating on plant health was already helping.
“Any edge we can get might just get us over the line for actually growing soil carbon.
“If it can trigger some biological processes, maybe it can prevent some of that carbon in cellulose from being released back into CO2 when it’s broken down.
“If you are building soil biology that is capturing it a bit more and putting it into a soil form of stable carbon, who knows – let’s wait and see.
Seeking carbon baseline
After conducting an EM38 survey of the farm and deep soil coring in 2007, Mr Fels is keen to gain a carbon baseline for the farm and is working in conjunction with Carbon Ag to mount a Veris module on their seeding bar for the coming season that will achieve that.
“I’m not interested in selling carbon credits, but I think it would be really good to do, and there is now the technology to do it – so as we are seeding, we will be getting a carbon baseline of the farm.
“If we do one day end up where carbon credits have a worthwhile commercial value, I want them sitting in our balance sheet.’’
“In 20 years’ time, it would be good to know what we have achieved and it will be good to compare with some of the 2007 results.
“I wouldn’t mind betting soil carbon could still be going down slowly because, despite what politicians like to tell us, it’s incredibly hard to grow, and also with the constantly increasing yield productivity we seem to be getting off this country.
“We are probably one tonne per hectare better than 10 years ago on the same country with the same rainfall, which is huge.
“That doesn’t come from nowhere and we are always playing catch-up with fertiliser rates to ensure we keep up to new productivity levels.
“Some of that would be coming out of soil, so we need to be staying in front of it.”
Mr Fels said the big challenge now was to keep growing soils as well as production.
“If you can’t measure it, you can’t manage it.”
Mr Fels is confident in the direction of the family’s continuous, disc-sown cropping operation, reinforced by improving soil health, grain yields and profits, as well as reduced inputs, and moving towards a farming system where the same simple methods can be applied successfully across their range of soils.
He also recognises the good fortune of farming young, quality country.
“In the early days, it was probably more about getting as much as you can out of the land than it was about putting back into it, but I think things have changed a lot in the last 20 or 30 years.’’
“Since no-till, we’ve been constantly improving and people are getting better productivity even on our traditionally poorer soils, but we are having to spend a fair bit of money to ameliorate them in certain cases, which is probably now a bit of catch-up from years of taking from those soils.
“All soils can be improved and it’s about being careful – treating them with kindness rather than just flogging them.
“Eliminating basic things (like bare ground) is good for a start.
“Then it’s about how we can keep building it from there.’’
Focus moved beyond chemical farming
He said over his 30 years in farming, agriculture had become a more technical, scientific and exciting industry to be in, and the focus was now moving beyond chemical farming.
“It was a revelation what we could achieve with chemicals and chemical fertilisers and how much it grew our productivity, but I think it has got to a point where ‘if a little bit is good, it doesn’t mean a lot is better’.
“The green revolution has brought us a long way, but I think now that agriculture has gone through that incredible period, we are realising there’s a bit more nuance to this.’’
“More people are now starting to think, ‘we can’t keep putting more and more stuff on this soil and think it’s going to make it better’.
“A lot of these products are actually designed to kill things when, as a farmer, I see my job as trying to grow things – it doesn’t all stack up when you think about it.
“It’s now more about, ‘let’s get down to the nitty gritty of what’s really helping and what’s interfering with the process of building our soils’.
“We can probably start taking some of those things out and replace them with things that are more positive in terms of soil health.”
Prophylactic insecticides out
Mr Fels said the family farm had not used prophylactic insecticides for three to four years, not even on canola, which he said people found “a bit shocking”.
“It’s become a bit normal for people to use broad-spectrum insecticides several times a year on their farms, which I’m a bit horrified what that’s doing to the soil biology that we are trying to grow.
“Imagine if we all took constant, broad-spectrum antibiotics – what that would do to our own health.”
Mr Fels said the family’s country was not getting any more insects without using insecticides.
” I think that’s because our system is becoming a bit more resilient.’’
A controlled traffic system, use of their own designed and built iPaddock-Alphadisc seeding rig on narrow rows for increased biomass production and full residue retention, and amelioration, including mouldboard ploughing, has dramatically improved soils and crop yields.
A stronger legume component in the rotation, where it is profitable, is now being considered to help further build resilience and allow herbicide rotation benefits.
Source: Carbon Ag