Grains: Soybeans fall 2.5%

US soybean futures tumbled more than 2.5 percent on Monday, reversing similar gains from the previous session, as a record-fast harvest pace and reports of larger-than-expected yields pressured prices.

Wheat futures dropped 2 percent, the fifth decline in six sessions, in a profit-taking setback and as rain forecast for the drought-parched US Plains was expected to boost winter wheat seeding.

Corn futures traded mixed as spillover pressure from sharply lower soy and wheat offset lingering support from a US government report on Friday that showed stockpiles of the grain had dropped.

US corn surged by the daily trading limit on Friday, jumping 5.6 percent after the US Department of Agriculture (USDA) shocked markets with a report that end-of-season stocks tumbled 12 percent from a year ago, coming in under 1 billion bushels for the first time in eight years.

Soybeans added nearly 2 percent on Friday despite a larger-than-expected USDA stocks figure, while wheat gained 5.5 percent in the steepest rally in three months as the USDA reported an unexpected drop in US wheat stocks.

The corn and soybean harvests maintained a record pace as dry weather allowed farmers to notch their best crop-gathering week of the year.

After the market closed, USDA said US corn was 54 percent harvested as of Sunday while 41 percent of soybeans were harvested.

Wheat prices plunged in a profit-taking pullback from Friday's sharp gains, which were triggered by an unexpected drop in wheat stocks in a USDA report, and as weekend rains soaked key areas of the US Plains hard red winter wheat belt.