In mid-2019, a group of 22 Australian soybean growers travelled across more than 3000 kilometres and five US states to learn from experienced growers and industry experts.
The vast distances they travelled on the July study tour, for which GRDC provided some investment, is a good metaphor for the huge size of the US area sown to soybeans.
Soy Australia chair Shane Causley likes to describe it geographically: "Imagine if we planted soybeans and corn in an area the size of Darwin to Adelaide and all the way to the east coast. That's the size of the American crop - all with rain."
The US produced 124 million tonnes of soybeans in 2018, compared to Australia's annual average of 60,000 to 100,000 tonnes.
Shane, who grows soybeans and sugarcane on his 263-hectare farm on Warregah Island, in northern New South Wales, helped organise the trip.
The study tour saw the Australian group visit field days, conferences, research facilities, factories, machinery manufacturers and 10 farms.
Studying strip till practices
The group was keen to better understand the use of strip till, a reduced-tillage practice that is increasingly being adopted by US soy and corn growers.
As part of a controlled-traffic operation, the practice sees residue moved to the side of a row, allowing seed and fertiliser to be placed more accurately.
This compares to older practices of preparing paddocks with a disc plough, a rotary hoe, a deep ripper, and then planting and broadcasting fertiliser.
To learn more about US strip tilling, the group visited farmers using strip till and manufacturers making implements designed for the job.
Shane says strip till suits the conditions faced by US growers.
"Their season is short, at 130 days, so any practice that quickens the preparation and planting process is important," he says.
"Also, they face a problem with too much water and too many paddock passes can quickly lead to bogged conditions."
Applicability for Australia
Despite climatic differences, this practice has great applicability in Australia, where similar time constraints between the harvesting of cane and the planting of soybeans occur. Additionally, wet conditions can cause trafficability issues in some seasons.
The US growers using strip till report that it improves soil health and can be used in corn, soybeans, cotton and peanuts.
"They indicated there are definite cost savings from not working the whole paddock multiple times," Shane says.
"They report up to US$40/ha (A$60/ha) in savings, plus there is a reduction in wind erosion because the stubble from the last plant is there."
This was echoed at Environmental Tillage Systems, a strip-till machinery factory in Minnesota, where the group saw the units used in corn and soybean paddocks to apply fertiliser prior to planting.
Standard practice sees heavy tillage occur in autumn to incorporate crop residues and phosphorus and potassium fertiliser. Then a lighter, shallow tillage is done in spring to dry and warm the soil and/or incorporate nitrogen, phosphorus and potassium fertiliser. Then a crop is planted.
Wet springs make this tillage difficult and heavily tilled paddocks can be soft and boggy.
"Multiple passes cost money and time and soil loss is a problem," Shane says.
"However, where reduced tillage has occurred, there has been improved timeliness of operations - growers are on paddocks earlier in autumn after rain and earlier in spring to cultivate."
Although a couple of the Australian growers on the trip already use strip till, more are now considering it as a result of the trip.
The short season faced by US growers also means that many farms are highly capitalised.
Where reduced tillage has occurred, there has been improved timeliness of operations - growers are on paddocks earlier in autumn after rain and earlier in spring to cultivate.
"They tend to have a lot of machinery to cultivate, plant and harvest in season. Plus, they have huge heated sheds holding all this machinery, a big difference compared to our way of farming," Shane says.
He says the short season has also seen more growers turning to biological stimulants.
"Because they have such a small window to do things, the stimulants are applied to seed, saving time," he says.
"When they do plant, it is cold and wet, and crops can take two weeks to emerge. Our ground is hot by comparison and it takes about three days for beans to emerge."
Lessons inspire Australian trial
After learning that US growers are using higher rates of potassium and phosphorus (75 to 150 kilograms/ha) than Australian growers, Shane has started an on-farm trial.
Their season is short, at 130 days, so any practice that quickens the preparation and planting process is important.
"(In the US) they are using 150kg/ha of potassium and our recommended rate is 65kg/ha," Shane says.
"This could be because we used to grow beans for green manure and our recommendations are still based on that, even though that is not always the case any more."
Shane is working on testing differing rates on his own farm.
Another novel practice for the Australian contingent to see was tile drainage.
Tile drainage is a type of drainage system that sees slotted pipes dug under paddocks to address waterlogging.
At a cost of up to A$600/ha, the system removes excess water from the soil below its surface.
On one of the farm visits - to Brian Lensch in Iowa - the Australian group saw the problems US growers had been having with excess water and how drainage was helping.
Brian farms 1540 hectares and strip tills in autumn and spring, normally planting corn in April. But in 2019 it was too wet for him to plant in the right window, so he switched 400 hectares to beans.
Brian described the weather their region had faced as "Farmageddon".
He says the wet weather started in autumn 2018 and was followed by too much snow in winter and too much rain in spring. However, his tile drainage had helped the farm cope and saw them plant on paddocks that would previously have been too waterlogged.
Shane says the Australian group heard that although tiling can be expensive, it has its benefits.
"For some farmers tiling has doubled their yield because it reduces the issues caused by waterlogging. And they can plant in areas not usually planted on because of water logging," he says.
An interesting stop on the tour was the National Strip-Till Conference, where Shane says the overriding theme was soil health.
One novel way of demonstrating how soil health had improved from strip-till farming came from soil scientist Frank Gibbs.
He pumps smoke into an infield drainage tile to help visualise - via the smoke coming up through the ground - how soil structure works and how much freer it is when strip tillage is in place.
The tour was also supported by Soy Australia Ltd, North Queensland Tropical Seeds, Bean Growers Australia, Mara Global Foods and PB Agrifood.
GRDC Research Code CAU1906-001AWX
More information: Shane Causley, firstname.lastname@example.org, 0400 603 884