By Julian Gairdner

Residual chemicals in watercourses could be a thing of the past thanks to a novel idea to reclaim active ingredients from the soil.

 The literally groundbreaking process developed at the Eindhoven Institute of Technology and Development aims to sift the top 45cm of soil post-harvest – using an adapted potato harvester – passing it through a mobile chemical extraction plant based on an ion exchanger.

According to researcher Jaah Torpfaam, up to 95% of residual active ingredients such as IPU and mecoprop can be recovered.

Working with German machinery manufacturer Worzthiz Rerbich, the Eindhoven team is now exploring how the technology might be applied at farm scale.

 “There are limitations,” Dr Torpfaam said. “Workrates are slow – about 2ha a day – and the process would add 40/ha to direct production costs.”

But he believes the environmental benefits and the savings that the water industry could make could enable the system to become economic for European growers.

“The water industry spends billions of euros a year extracting pesticides. If they were to pay even half of the grower costs for the process, they would be significantly better off.”

But WAKE-UP, the European water industry confederation, said they only had an obligation to their customers, not to line farmers” pockets. “We are interested to see how the technology develops,” a spokesman said. “But ultimately it is a farmer”s responsibility to ensure they are not polluting.”

The system, which should go on sale at the end of the year and will be available in any colour, will also allow plastic cans to be recycled.

“Growers will have to ensure they use the right cans according to the pesticide they are extracting,” Dr Torpfaam said. “Otherwise there could be problems with label recommendations.”

Meanwhile, the British Universities Research Organisation for Worms (BUROW) claims the idea would be an environmental disaster. “This would exacerbate the mechanical damage already done to earthworms,” said Nog Round. “We understand there is 20% soil loss with each post-harvest pass – where is all that soil going?”

The Voluntary Initiative refused to comment.

julian.gairdner@rbi.co.uk