Returning it to the atmosphere could be considered in the long term to be redressing an accident of nature; in the short term it is presenting us with some interesting challenges."
The major challenge is in production efficiency. Dr Jamieson works in Canterbury, where the weather is extremely variable and where soils are often free-draining and relatively poor in nutrients.
High yields of crops can be obtained only if irrigation and nutrients are applied at the right amount at the right time.
His research is identifying strategies to help farmers cope with the various scenarios associated with El Nino and La Nina weather patterns.
"Carbon dioxide is an atmospheric fertiliser," said Dr Jamieson.
"That means crops can grow faster than at the beginning of last century, but warmer conditions mean they don't grow for as long. To take advantage of increased atmospheric fertility, we need more soil fertility to overcome the effects of the shorter growth period."
Computer modelling can predict exactly how much irrigation and fertiliser is needed for any combination of crop, season and soil.
The research is aimed at maximising farmer profit and avoiding environmental harm, and the system meant all farmers could perform nearly as well as the best producers.
* Jacqueline Rowarth is president of the New Zealand Institute of Agricultural Science and research director at Unitec.
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