Technology allows efficient fert application

But new research will further improve the productivity of New Zealand’s hill country farmers, the company says.

Presenting their findings at the 30th Annual Fertiliser Lime and Research Workshop recently, Michael White, Ravensdown development manager, and Dr Ants Roberts, chief scientific officer, outlined results from 40 commercial fertiliser applications that have used the variable rate technology.

“On the 40 farms an average of 9% of the land has either been environmentally sensitive or non-productive, which is well above what we expected. Being able to avoid such land during fertiliser application brings environmental gains and may save money,” says White.

“In fert spreading precision, pilots and aerial spreading operators have for years done the best they can with the technology they had.

“Only now are technology developments emerging that allow hill country farmers to begin to pick and choose where to apply, or not apply, their fertiliser. If of sufficient size, a stream, some scrub or a sacred site can be mapped and avoided more easily, cost effectively and safely,” says White.

Using AgResearch’s PKS lime econometric model, they then compared a variable rate application to a blanket fertiliser strategy on four farm-modelled scenarios. Farm economist Phil Journeaux reviewed and supplied the Overseer nutrient budgets and productivity weightings.

“What we have found over the four econometric scenarios we analysed is that within 10 years all farms were more profitable using the variable rate fertiliser strategy,” says White.

“On average, the farm scenarios were $43/ha better off in that timeframe than they would have been using a blanket spreading strategy for a typical North and South Island farm. It also proved more sustainable, when tested against volatile returns for farm profitability over the ten years.”

The variable rate spreading technology is an ancillary programme funded by Ravensdown in support of its joint Primary Growth Partnership programme with the Ministry for Primary Industries -- called Pioneering to Precision, which is aiming to develop aerial soil testing technology using hyperspectral imagery.

Now in year four of its seven-year programme, Ravensdown is identifying considerable productivity potential between differing land management units on hill country farms.

“It’s important that our research is going to be economically viable for it to be adopted by farmers. What this research proves is that farmers can have confidence in the technology right now, in its early stages, knowing all the while that further technological advancements in GPS guidance and automation will allow greater efficiencies and effectiveness down the line.”