An agribusiness expert says a prediction of a long boom in commodity prices may be too optimistic.
The Ministry of Agriculture and Forestry's annual stocktake predicts that the value of dairy and forestry exports will grow by up to 70% by 2014.
The report assumes that a Chinese-fuelled boom in commodity prices will continue and that the exchange rate will fall sharply to about 50 US cents.
The professor of agribusiness at Lincoln University, Keith Woodford, says individual farm businesses shouldn't bank on the forecast coming true.
He says the prediction is optimistic because historically the chance of being right about the exchange rate is about 50-50.
Caution advised on Chinese returns
The ministry projections point to lifting export values in most primary industries next year except grains and seeds, and lamb and venison.
The report shows exports of agricultural and forestry products to China last year jumped 49% to more than $2 billion, mainly in dairy and log exports .
However, the ministry's director-general, Murray Sherwin, cautions that the dominance of those sectors and China's hunger for their products should not preclude the development of other products and other markets.
The country will need to watch out it does not become too reliant on one country, Mr Sherwin says.
The meat processor and exporter Silver Fern Farms is also warning competitors not to get carried away about potential returns from China, saying demand for high-end lamb and beef is likely to be restricted to niche areas like hotels.