Commodity prices have risen due to higher dairy prices, reversing seven successive months of decline.
The ANZ Bank's commodity price index rose 0.5% in August compared with the previous month, though it's still 15% weaker than the same period a year ago.
Along with an increase in dairy prices, which have a 43% weighting in the index, beef and kiwifruit also rose, while wool, wood pulp, apples and aluminium all declined.
But ANZ economist Steve Edwards says an appreciating New Zealand dollar reduced returns at the farmgate by 0.8%.
''(We) are starting to see a turnaround in dairying, whereas Australia is now seeing a fall in prices for coal and ore,'' he said.