Saving soil with intelligent machine use

Did we really run over our fields at random in 30 ton farming vehicles? Agri-consultant Tim Chamen wants to stop it happening now.

Tim Chamen

Speak to any experienced garden vegetable grower about the acceptability of running a car over their vegetable plot and I guess they would look at you in horror!

And yet this is what farmers worldwide have done with their machines for many years because of the difficulty of doing otherwise. As the drive for improved production efficiency has risen together with labour costs (PDF, 41pp), farm machines have increased dramatically in size and crucially in weight.

When soil at 0.5m depth changes (and mostly for the worse) as a result of surface pressure, it is often uneconomic to repair in the short term and may take decades through natural processes. And the process is self-perpetuating: a heavier machine creates more compaction and a yet bigger and more powerful tractor is needed to try and remove it! It’s a vicious circle and yet there’s been little impetus to break it.

I’ll give you the key: tractors are getting bigger and heavier.

Soil compaction is a serious problem. Crop yields on average are reduced by 12% due to soil compaction while energy inputs can often be doubled. Similarly, compacted soils don’t absorb as much water leading to fertiliser run-off, soil erosion and loss of chemicals and nutrients. Water-logging events can also rise, leading to increased emissions of nitrous oxide, a gas about 300 times more damaging to the atmosphere than carbon dioxide.

Controlled Traffic Farming

What then is the solution? Although we can’t tend the land without running on it, there is now a clever way of confining wheels or tracks to narrow strips in the field to just 15% of the area, something we call ’Controlled Traffic Farming’ (CTF).

This has been made possible (or at least a lot easier) over the last decade or so by global navigation satellite systems (GNSS, more commonly referred to as GPS). Top guidance equipment can now auto-steer most farm machines to an accuracy of about 2cm; an amazing feat considering the complexity and speed of calculations needed!

Screenshot of a CTF principles animationControlled Traffic Farming
Click the image above to see a simple animation of CTF principles.

But there is far more to achieving CTF than just investing in GNSS technology; all the machines in the farming system must match up in working width and the distance between the wheels or tracks. Manufacturers of farm machines have never considered this in their designs, but that is now changing and the benefits to farmers, food production and the environment are widespread and significant.

Where to from here?

For the past ten years, we as a small advocacy organisation have tried to facilitate CTF systems in Europe, but uptake is still limited. At present, only about 1.5% of the arable area in the UK is in CTF, and a much smaller proportion in Europe as a whole while it’s practically absent in the developing world

One wonders why the EU or national governments have not been more supportive in promoting these systems when they so obviously lead to increased production efficiency with reduced environmental impact – something they have been harping on about for many years!

CTF seeks to reduce traffic area to grow more food from the same land.

One of the main barriers to adoption as I see it is the perceived extra cost. In reality, farms often save huge amounts on machinery investment (number and size of tractors for example) and their running costs consistently fall. CTF is still often left out of the debate in the popular farming press when it so obviously addresses the problems that are being discussed, and this is very frustrating.

What’s more, change in agriculture is notoriously slow, largely because many individuals are involved, with each having to be made aware of CTF and then convinced that it is in their interests to change. CTF also needs a fair bit of thought but once introduced makes life a lot easier.

On the positive side, Australia already has widespread adoption and is spending AUD3 million on CTF research. Adoption there has been driven by water availability – compacted soils are very poor at holding on to water!

And getting farmers converted with existing equipment is only the beginning; far greater things can be achieved with a complete revision of our mechanisation systems as envisaged by Halkett in the 1850s! He recognised the compaction issue and devised a machine that could leave 95% of any field free of compaction for all time, boosting yield and maintaining soil quality.

We must improve the uptake of CTF in the UK and abroad to at least a quarter of the area farmed. Otherwise it will remain an issue we’ll only have to address in years to come, with some disbelief that we didn’t tackle it sooner.

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About Tim Chamen

Tim Chamen has a degree in agricultural engineering and spent 25 years at Silsoe Research Institute where he worked on tillage tool development and the effects of machinery compaction on soil and crop responses. Since leaving Silsoe in 1996 he has worked independently, undertaking contracts for machinery manufacturers, the EU and others and was granted a PhD from Cranfield University in 2011 on traffic compaction in agriculture. He set up Controlled Traffic Farming (CTF Europe) Ltd in 2007 as a focus for CTF advice and the company now has five partners across Europe.

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