No-till techniques have revolutionised arable farming in Australia, but what can UK farmers learn from their antipodean counterparts? Ryan Gue and Ed Trotter of Strutt & Parker share their learning after a recent study tour of Australia.

Where did you visit?

We visited six farms in total around New South Wales from Merriwagga to Quirindi, covering 1,000 miles. Farms ranged from 1,500ha to 8,000ha, only one of which was irrigated.

We also followed an agronomist who spoke to us about their crop protection strategies and saw a wide range of farming approaches.

How widespread is the adoption of no-till in Australia and what has driven that change?

The start of the change happened in the 1980s with the adoption of stubble retention, however there still are some farmers using traditional techniques.

See also: How to meet the growing demand for wheat

But it is widely accepted that no-till is the most sustainable system for the future, especially in the dry regions, where wind erosion and soil moisture dictate why the vast majority use this approach.

Many farmers switched from sheep production to arable farming in the 1990s after the 1991 Australian wool price crash forced farmers out of sheep farming. They then chose to move to no-till systems.

What are the key crops grown in Australia and has no-till been used more for a particular crop?

Milling wheat, barley and oilseed rape were all commonplace in the area we visited and are suited to no-till. Some farmers also grew chickpeas and lucerne. The stubbles on all crops were left relatively high and the next crop sown inter-row, meaning stubble could protect the crop.

The irrigated farm we visited struggled to use no-till as it grew crops such as cotton and soya. On top of this, the irrigation channels in the field meant no-till was less of an option.

How were the farms you visited performing? What are the benefits they’re seeing and what are the challenges?

This year yields have generally been good. There are regional differences, of course, but wheat yields in dry areas (about 300mm of rainfall a season) were about 2t/ha, which is an average yield for them.

However, on one particular farm, a hail storm completely decimated a 200ha block of oilseed rape, which meant it was not worth harvesting. This kind of localised weather is not unusual for Australia.

The general view is that yields are more consistent now and the stubble residue covering the soil from no-till is having a huge benefit on wind erosion and soil organic matter. In turn, this helps against their biggest limiting factor, which is soil moisture. If they can retain more moisture this will help tiller survival and specific weight.

This method is also cheaper than multiple cultivations that were previously used as they can use huge 60ft-plus drills, which all saves fuel and labour.

The biggest drawback is the weed build-up. Many farmers are experiencing worrying levels of herbicide resistance in ryegrass, but they are working around it using more cultural control.

Compaction can be an issue in some areas but can be combated by using control traffic systems (where there are permanent tramlines) with subsoiling.

In what situations was the no-till approach working best?

The system seemed to work well for the majority of soil types. We were told the soil is now in a much better condition than when they started, thus allowing better workability and higher organic levels. Most importantly, moisture retention meant crops were more likely to survive the arid conditions.

What sort of machinery looked to be working best and how are people approaching drilling?

The type of drill used depends on the amount of time that has been spent in no-till. Tines are used when converting to no-till, whereas once the soil structure is established, discs are used as they disturb less soil.

However, on heavier sodic soils, it was found that heavy rain can wash smaller soil particles down the soil profile, through the well-structured soils, eventually depositing them 50cm down and drying out. This creates a pan lower down the profile, limiting rooting. To combat this the farmer affected has moved to sub-soiling. This retains soil cover and combats the pan.

Weed control can be a challenge. How are people addressing the problem of resistant weeds?

It was surprising how relaxed everyone we spoke to was about resistance, given glyphosate resistance was first discovered in annual ryegrass back in 1996.

Common practice is to use a one-in-four-year rotation of herbicides (some farmers chose their cropping rotation to allow a range of active ingredients to be used), and to use “double-knock” chemical applications when controlling stubble. This included an application of glyphosate or Garlon (triclopyr) followed 14 days later by diquat.

Kelly chains (similar to harrows) have been used to physically destroy weeds, leaving them mechanically damaged and more vulnerable to herbicides. However, some felt it disturbed too much soil and deposited seeds further down the soil profile.

What have been the implications for rotations?

Cropping was generally wheat, barley and oilseed rape with potentially some chickpeas. Some farmers would include fallow years in their rotation to deal with weeds.

However, there were years where fields were forced to be fallow due to low rainfall. This happened three years in 10 on average. A fallow field receives five sprays across the year.

How are crops are typically managed through the season?

Fertiliser application was surprising. Nitrogen was only put on at low levels at drilling or not at all in some instances. Phosphorus was the main element applied.

The principle was to increase levels of P from low levels of 3-5 to getting the soil to above 30 (Colwell P) and maintaining that level.

One grower showed us how he mixed his own fertiliser, which contained high levels of micronutrients. The mix contained molybdenum, boron, phosphate, X15 (his own mix of micronutrients, which among other things included kelp), UAN (a solution of urea and ammonium nitrate) and CalSap (calcium and molasses).

This gave cost savings and a trusted, reliable product that could be tailored for certain fields and crops after extensive soil testing was carried out.

This came about for two reasons. It was concluded that prilled monoammonium phosphate placed at sowing decreased pH causing acidic conditions, which had a negative effect on germination. Second, when chicken manure was applied to a field, it doubled yield versus control, which lead to suspicion of deficiency.

Another farmer was experimentally trialling putting molasses behind subsoiler legs to feed soil microbes, which would increase rooting, mineralise nutrients from the soil, and increase soil health. The design for the drill was still being finalised, but it was a very interesting concept.

What is the take-home message for UK growers?

With regards to machinery, don’t settle for something that doesn’t fit your specific system.

It was normal to adapt machinery to suit the farm, as almost every farm has a different combination of conditions and techniques. One farmer even built his own sprayers out of old cotton harvesters when he couldn’t find a suitable machine.

Also, growers shouldn’t be afraid of mixing their own fertilisers to tailor their nutrient applications to really push output.

The less soil that is moved, the better – this left weed seeds at the surface to germinate and then be killed by herbicides. This, along with rotational use of herbicide and fallow years, helped keep weed issues at bay.

It was also mentioned repeatedly to not expect an immediate financial gain from no-till.

Some growers suggested it could be five years until a significant difference is made to the general performance of the soils, and 10 years until a financial gain is realised from switching to no-till.