Fertiliser suppliers and other industries that sell to farmers are losing income as the effect of the drought continues.
All the North Island and the Buller and Grey District in the South Island are official drought zones. Niwa scientists say they believe the North Island's drought is the worst since the early 1970s.
Ravensdown marketing general manager Mike Whitty says the agricultural fertiliser supplier has seen a big drop in orders during the last six weeks, down by nearly 50% in some places.
Rural services company PGG Wrightson also reports farmers are spending less.
Regional manager for East Coast and Bay of Plenty Tom Mowat says sales have fallen 15 - 20% overall, though purchases of stock feed have risen by 50%.
The Agricultural Aviation Association says farmers' demand for aerial top-dressing is 50% down.
Executive officer John Sinclair said aerial weed-spraying services have probably been cut even more, because plants close up in drought and there is a significant risk that they will not be killed if they are sprayed in that condition.
Mr Sinclair says it's now too close to winter for the industry to hope for a change in fortunes this season.