The imports of edible oil slowed in China in the first eight months, affected by the shrinking foreign supply and the related duty policy change.

The General Administration of Customs (GAC) said on Tuesday that China imported 5.39 million tons of edible oil between January and August this year, up 4.7 percent year on year, but 18.9 percentage points lower than the 23.6 percent increase in the same period last year.

The edible oil imports peaked at 900,500 tonnes in April, but sharply fell to 508,000 tonnes in June, the smallest monthly amount since the beginning of 2007.

The volume rebounded in July with 730,000 tonnes of imports, but fell back again to 580,000 tonnes in August.

The slowing imports were mainly blamed on shrinking soybean supply from Argentina, China's biggest soybean supplier, the customs said.

The soybean exports dropped sharply in Argentina as farmers went on strike in opposition of government's decision to float exports duties for farm produce.

In addition, the preferential policy on soybean imports, namely the one percent import duty was extended to September 30, which helped make soybean a substitute for soybean-turned oil, according to the customs.

To reduce the cost of soybean imports and curb price rises for grain on the domestic market, China slashed import duty on soybeans from three percent to one percent on October 1, 2007.

The GAC said in an analytical report that China relied too much on foreign exports of edible oil, so was prone to the risks of  international price volatility, which posed a threat to the national grain security.

The report suggested that the government unveil an incentive policy to stabilize domestic soybean planting, and encourage the growth of a high-yield breed of edible oil raw material to lessen dependence on foreign supply.

The domestic key enterprises in soybean planting should be supported in their business expansion in order to break the monopoly of the international heavyweights, the report said.

China's edible oil imports has soared more than 200 times from the 1986 level. Some 8.38 million tons was imported in 2007, of which most of the imports were soybeans.

Before 1995, China had been a major producer and net exporter of soybean. But it became a net importer in the five years thereafter.