Agri economist Con Williams yesterday said over the course of 2015, international prices fell 12.9% year-on-year and were 29% below their early 2014 peak.
New Zealand dollar prices fell 3.9% in December as the higher kiwi compounded the fall in international commodity prices.
The currency played a buffering role for most commodity export sectors last year, he said.
On an annual basis, New Zealand dollar prices were back only 1.1%, largely due to the 7% fall in the dollar's trade-weighted index and a 13% fall in the NZD/USD cross rate.
By major sector, December falls were evident for dairy, meat and horticulture prices.
That was offset partly by higher forestry and aluminium prices. Seafood prices were unchanged.
International dairy prices fell 3.5% in December and in New Zealand dollar terms, they were back 5.6% in the month.
Weakness centred on milk powder prices as general commodity sentiment, high European milk supply, weak Chinese import demands and other major importer/buyers generally being well stocked weighed on prices, Mr Williams said.
Milk fat products performed slightly better and butter prices were up 5.2% in the month.
Non-dairy prices fell 0.2% in December, the eighth consecutive monthly fall, and prices were 17% below historic peaks.
The higher dollar again contributed to the fall in non-dairy export prices which were now back 10% since September, he said.
