Soybeans are leading a big sell-off in grains trading after the government released its latest crop report.

The Agriculture Department says Wednesday that soybean stockpiles are larger than expected. And it forecasts that farmers will plant 78.1 million acres of beans. That would make 2010 another record year of production.

May soybeans are down 39.5 cents, or 4.1 percent, at $9.345 a bushel in midday trading. The drop is similar to the slide two months ago after a USDA report showed bigger-than-expected production.

Corn plantings are also expected to go up this year. The USDA estimates farmers will plant 88.8 million acres.

May corn is down 8.25 cents, or 2.3 percent, at $3.4625 a bushel.