Traditionally, it seems the U.S. Department of Agriculture’s (USDA) January reports have had their share of surprises, maybe even more so given the breadth of numbers released on that day. This year’s reports seemed almost benign by those historical standards, but there were two surprises that will have repercussions over the next number of months.

First, the USDA revised the soybean yield and production down, not up as the trade had anticipated. And even though acreage is extremely low by historical standards, U.S. producers again chose to plant less land to winter...