"More than half of the farmers in the cooperative will shift to corn from soy this year because corn last year had given very good returns," Chen Yangui, head of the Heilongjiang Qiqihar Soybean Association in the country's northeast, told Reuters.

"Corn was popular and sold immediately after it was harvested."

Farmers last year made 1,000 yuan per mu of corn, an area equivalent to 0.06 hectare, far higher than the 600 yuan earned from the same unit of soy, Chen said.

Farmers in northern Heilongjiang are growing more early-maturing corn seeds, which can mature within 110 days and escape early frost frequent at harvest there, he added.

The soy acreage in Heilongjiang, which produces 40 per cent of China's soy, would fall by a fifth this year, in its third year of decrease in a row, said Wang Xiaoyu, deputy secretary general of the Heilongjiang Soybean Association.

In the neighbouring province of Jilin, the second largest corn-growing region, farmer Fu Yanming said he would double his corn acreage this year.

DRYNESS, PLANTING COSTS

Some 34 per cent of farmland in the northeast, the country's corn belt, is experiencing dry weather, the China National Grain and Oils Information Center said.

March rain had not helped break the drought, a key factor that threatens to delay planting, the agriculture ministry said.

Although some farmers told Reuters they had access to irrigation, they worry over rising planting costs.

"I hope the corn prices next year could be as high as last year, which can cover the rising planting costs," said Fu in Jilin.

Domestic physical corn prices at the largest port of Dalian

YC-FOBDLN hit a record of 2,480 yuan per tonne before harvest in October. The rise eased before rebounding last month to 2,440 yuan on tight domestic supply.

Hilongjian's Chen said farmers had to pay 20 per cent more to rent land from other farmers, besides an increases of 10 per cent in fertiliser and seeds prices.