The chief executive of the country's biggest farming enterprise Landcorp told a primary industry forum in Wellington that there is still lots of land available for irrigation in New Zealand and the gains to be made from it are enormous.
Chris Kelly referred to NZIER figures that show proposed new irrigation schemes would generate more than $2 billion extra in farm production and an additional $4 billion in earnings from processed goods.
Landcorp has calculated the production benefits from irrigating several dryland farms it has in Canterbury.
He says the economic gains from irrigating some of Lancorp's dry lands make for a compelling argument although he acknowledges that irrigation brings environmental and other challenges as well.
Executive director of the Ecologic Foundation, Guy Salmon, told the forum that agricultural productivity statistics showing the gains from irrigation need to be weighed up against the costs of using the water.
He says when the true cost of using an external resource, such as water, is factored into the calculations then a more accurate picture of productivity gains can be made.
Mr Salmon predicts that trading in water use and discharge rights, now starting to show up in regions like Canterbury and Taupo, will become more common.