Greenhouse gases measured remotely

AgResearch soil scientist Tony van der Weerden demonstrates specially designed chambers to allow scientists to remotely sample nitrous oxide emissions from paddocks. Photo by Tuangane Matangi.

AgResearch has come up with a way to measure nitrous oxide emissions from paddocks using a caravan to hold the software and hardware necessary to measure levels remotely.

Speaking at the recent Southern Field Days, at Waimumu, AgResearch soil scientist Dr Tony van der Weerden said up until now scientists had to measure nitrous oxide levels manually, on site, which was expensive.

Testing emission levels would quantify how much nitrous oxide or greenhouse gases were being emitted, and Dr van der Weerden said solutions to mitigate the emissions could then be developed.

"In terms of reducing these emissions, it's huge, because by 2013 agriculture will be part of the emissions trading scheme (ETS), and we need to find ways of reducing these gases for farmers to reduce the potential liability that they might pay," he said.

The caravan would be set up on a paddock and then scientists would be able to retrieve the sampling information remotely from their offices, instead of previous methods where manual samples had to be taken and sent to laboratories for analysis.

"We can take a number of samples frequently and we get the results straight away," Dr van der Weerden said.

The caravan housed software and hardware purposely designed and programmed to read greenhouse gas emissions.

Nine closed chambers were placed on the grass to collect the samples and a pump was used to circulate the air which would then go to an air line and the analyser.

"It measures the concentration in that circulated area and then it [moves] to the next chamber and does the same thing," Dr van der Weerden said.

"It takes a number of samples, five or 10, and the concentration typically increases with each sample, and from that we can calculate the amount of nitrous oxide coming out of the grass," he said.

While the technology was promising, Dr van der Weerden said it still needed to be measured against the standard technique.

Funded by the Ministry of Agriculture and Forestry, the caravan allowed remote and frequent sampling, and was more cost-effective for analysis, he said.