Reduce traffic and get soil in pole position

Over the past decade there has been a drive towards the adoption of conservation agriculture to reduce costs and increase carbon sequestration. But this is causing concern due to the potentially negative effects of increased soil compaction. So, how can we reduce costs, increase sequestration and reduce compaction?

Controlled traffic farming could be the answer.

The state of soils is critical in terms of their potential to mitigate or add to global warming. Compaction reduces soil aeration, infiltration and increases the risk of water-logging and enhanced greenhouse gas emissions.

Extensive studies have shown that uncontrolled compaction by field machinery can reduce nitrogen use efficiency by around 15%, evidenced in a similar increase in crop yield if compaction is avoided. In addition, there is mounting evidence that the poor soil aeration associated with compaction leads to greater emissions of nitrous oxide and methane, both extremely pernicious greenhouse gases. Nitrous oxide is a direct loss of nitrogen to the atmosphere that was destined for the crop, so not good on the pocket either!

If compaction is avoided, soil porosity increases in the range 5-70% and nitrous oxide emissions are reduced by 20-72% together with a 5-20 fold increase in methane oxidation.

So how do you avoid soil compaction I hear you ask! Well, you don' t avoid it exactly, you just confine it to the least possible area. Presently our production systems track around 80% of our fields every year. With a technique known as Controlled Traffic Farming, you can turn this statistic on its head and leave 80% of the field "traffic free".

Evidence that soil compaction has the potential to increase greenhouse gas emissions, either directly or indirectly, is substantial. However, detailed research on the subject has so far been limited. Quantification of the benefits of compaction avoidance in terms of nitrous oxide emissions may be possible through the use of well developed models.

The important point is that maintaining good soil structure is key to profitable and efficient farming and it’s good for the environment too.

Tim Chamen runs Controlled Traffic Farming, a consultancy service for farmers and growers across Europe to convert to CTF.

Find out more:
• Visit the Controlled traffic farming website
• Read FF’s  soil management factsheet here
• Visit the AHRF’s Soil Information Gateway