Lower international commodity prices and less favourable weather could help cut exports by $3 billion in the year ahead, according to BNZ.
A research note by BNZ economist Doug Steel said four external factors of weather, world product prices, interest rates and exchange rates "seemingly one-by-one, appear to be turning a bit sour for the agriculture sector".
Clearly heading in the wrong direction were global commodity prices, Steel said. The 10 per cent drop in international dairy prices at the recent GlobalDairyTrade auction was the latest example, he said.
"Overall, we estimate that international prices for NZ's export primary products are about 12 per cent lower than a year ago."
The weather, world prices and interest rates had generally been favourable for agricultural performance during the past year or so, Steel said.