The country's farm exports is forecast to go down 5 per cent for 2012-13 to $34.4 billion from $36 billion. The Australian Bureau of Agricultural and Resource Economics and Sciences (ABARES) issued the downgrade on Tuesday in its March forecast.

The bureau explained the decline to the continued strength of the Australian currency and the effect on exports of lower overseas commodity sales. The decline in farm exports is part of the expected lower forecast value of primary production exports by 2 per cent to $38.1 billion from $38.9 billion.

However, it is still higher than the five-year average of $29.7 billion.

The overall decline in farm exports is because of the fall in value of major crop exports such as wheat, barley, cotton, sugar, sorghum and canola which would negate the rise in export of wine, lamb, beef and wool, and the strong demand from the Asian region.

ABARES acting Director Kim Ritman pointed out that average wheat prices fell to $260 a tonne from $298 a tonne in 2011-12. However, prices of beef and veal are expected to remain relatively high at an average price of 320 cents a kilogramme.

Products whose export volume are expected to rise are timber by 3.4 per cent to $2.4 billion and seafood and fisheries products by 2 per cent to $1.3 billion.

Also expected to register a substantial increase by 13 per cent is the export of sugar which is projected to reach 3.35 million metric tonnes from the 2.96 million metric tonnes estimate in March. Raw sugar production is also anticipated to go up to 4.4 million metric tonnes from 4.25 million.

"An uplift of estimates in Australian sugar production and our export programme, in conjunction with rising production elsewhere, certainly does mean that prices are likely to come under a lot of downward pressure.... There's quite a lot of sugar around," Bloomberg quoted National Australia Bank agribusiness economist Michael Creed.