One of the companies selling a chemical product, small traces of which have been found in milk products, says regional councils will now have to be patient with farmers who can no longer use it to reduce nitrogen leaching.
On Thursday, the Ravensdown and Ballance Agri-Nutrients fertiliser companies suspended the use of items containing dicyandiamide (DCD), after improved testing found small traces in milk powder.
Sprayed on pastures in spring and autumn, products containing DCD are used on 500 dairy farms to reduce nitrogen leaching.
Ballance says regional councils have factored the availability of these tools into their plans, but now need to understand they are not available.
Ravensdown introduced DCD in the form of the spray Eco-N to the market in 2004.