China's soybean imports rose 8.6 percent year on year to reach 63.38 million tons in 2013.

Some grain dealers also resorted to filling warehouses with imports as precautionary measures amid concerns that drought in central China's grain growing areas, the worst in decades, might affect winter wheat production.

Still, China's corn and rice inventories remain at relatively high levels that are enough to feed the population for six months, Cheng said.

Early in June, Zhao Shuanglian, chairman of China Grain Reserves Corp (Sinograin), proposed stockpiling domestic grain and certain imports for national grain reserves that could cover almost 20 percent of national consumption by 2020.

According to Zhao, roughly 80 percent of grain warehouses will be filled by domestic production and the rest will be covered by imports.