Fertiliser statistics show the rapid rise in the use of nitrogen fertiliser has levelled off as farmers learn to use it more efficiently.
Nitrogen is an essential nutrient for plant growth and is used to boost pasture production, mainly on dairy farms.
The fertiliser industry research organisation says nitrogen use on New Zealand farms took off in the 1990s, as farming became more intensive, especially in the dairy sector.
Fert Research's technical director Dr Philip Mladenov says there's a perception that nitrogen use continues to rise dramatically each year.
However, he says the statistics show it peaked in the 2004-05 season at 355,000 tonnes and since then it has stabilised.
Dr Mladenov says sheep and beef farmers have increased their fertiliser use again.
That's confirmed by figures that show phosphate sales increased significantly in the 2010-11 season.
During the previous year, phosphate use dropped by about a third on the peak years between 2003 and 2005 and some farmers applied no fertiliser at all.
Dr Mladenov says the increase reflects improved economic conditions on sheep and beef farms, where most phosphate fertiliser is used.