The company that wants to mine rock phosphate from the seabed east of New Zealand expects to hear next month whether it will get approval.
Chatham Rock Phosphate has mining licence covering more than 800 square kilometres of the Chatham Rise about 450km off the Canterbury coast. But it needs a marine consent for the operation to take up to 1.5 million tonnes of rock phosphate a year from the sea floor.
A committee appointed by the Environmental Protection Authority finished hearing submissions last week and was due to make its decision by the end of January.
In the meantime, the company had been doing further work to assess the performance of Chatham Rock Phosphate compared with other fertilisers on the market.
Chief executive Chris Castle said glasshouse trials by Lincoln and AgResearch scientists confirmed its effectiveness as a direct application fertiliser.
"Really we know what the outcome was going to be. We knew that the results would be good, but one particularly interesting surprise this time was the fact that the uptake (by the plants) was very quick.
"The trials back in the 80's showed that the Chatham Rock Phosphate was a slow starter, it took a while to catch up and eventually it had the same efficacy as super phosphate. The difference this time was that it was up and running right away."
Mr Castle said Chatham Rock Phosphate was planning to do field trials next year.
The timing of those would depend on the outcome of is marine consent application, which has been opposed by environmental groups as well as fishing and Maori interests concerned about the impact of the mining operation on the sea floor and marine life.
"If the application is not immediately approved, we'll probably defer our tests because we'll be in a position where we'll be fundraising for the next stage of the legal process. We have no intention of going away. If this is not approved, we will either appeal or we can relodge (the application)."
Mr Castle was confident the application would succeed, despite strong oppostion.
"There's been some strongly expressed opinions, but the facts have stacked up well and the experts acting for the oppositon have actually agreed with our experts - that there's no effect on fishing, the effects on the environment will be short term and sporadic and cover a very limited footprint of the Chatham Rise, so I'm very, very confident of a successful outcome."