Was the earnings guidance upgrade that Monsanto (NYSE:MON) put out Sunday night the real McCoy or just a bunch of fertilizer? Wednesday, we'll find out.

On Dec. 5, Monsanto did something you don't see companies do every day: It doubled the earnings guidance for its first quarter 2006 from $0.10 to $0.20 per diluted share. The announcement sparked a quick 3.6% rise in the stock's price, which has subsided somewhat since (as has, indeed, the broader stock market). As related by fellow Fool Brian Gorman, improved performance of cotton in Australia, combined with better-than-expected sales of its ubiquitous (and as I can vouch, incredibly effective) Roundup herbicide in the U.S. lay behind the heightened expectations for the quarter just ended.

This explains the quick about-face in analyst expectations for the stock as well. As you can see from the table here, analysts were calling for about $0.11 per share up until 30 days ago; now they expect to see $0.19 -- meaning they continue to take Monsanto's assertion with at least a grain of salt. You'd think by now, though, that they'd have learned better. Monsanto has already "beaten" consensus estimates three times in a row over the last four quarters. So when the company promises a definite number for a quarter that was essentially complete when it made the announcement, chances are it's not going to fall short when officially reporting those results a few weeks later.

In short, expect a positive "earnings surprise" Wednesday -- but one that should come as a surprise to absolutely no one.

Now that we have Wednesday's news out of the way, let's take a quick look farther down the road. In addition to the Q1 number, Monsanto gave us some guidance on what to expect the rest of this fiscal year: essentially nothing new. Full-year guidance remained unchanged at $2.35 to $2.50 per diluted share -- not because the company expects its good Q1 performance to evaporate later on, but rather because it expects its suppliers to pass certain oil-related price increases on to it.

Free cash flow for the year should similarly remain about the same as previously expected, at $825 million to $900 million. That's a wide range, but take note: Even the low point on that cash-producing continuum would far exceed the $670 million that is the most Monsanto expects to report as profits under generally accepted accounting principles for the year. In other words, Monsanto doesn't just help farmers grow cash crops -- it's a bit of a cash cow itself.

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Fool contributor Rich Smith has no position in Monsanto.