China's grain imports grew substantially in the first half of this year and its reliance on overseas markets hit a new high, raising concern about food security and that farmers may reduce the area they plant.

Imports of all kinds of grain grew by 41.2 percent to 40.85 million metric tons in the first half of this year, according to the General Administration of Customs.

Corn imports hit 2.4 million tons, a 65-fold increase over the same period last year. Other major grain imports also grew significantly. Wheat imports surged by 295 percent and rice by 227 percent.

A drop in the quality in some grains and a higher price of domestic grain has fueled China's appetite for the imports, experts said. Domestic corn prices are among the highest in the world.

Li Guoxiang, an agriculture expert at the Chinese Academy of Social Sciences, said extreme weather in North America has affected corn and soy crops raising the prices. This will likely dampen imports in the second half of this year.

But even with that, this year's imports are likely to surpass 10 percent of the domestic production.

"The growth in grain imports will discourage domestic farmers and they may reduce the area they plant. The subsequent drop in domestic production will stimulate more imports, and thus depress domestic planting," said Li Changping, another agriculture expert.