American farmers are mostly upbeat, except ...

Daniel Acker | Bloomberg | Getty Images

Farmers and agribusiness interests are positive overall about the state of their industry, just as they were last year, according to the release this week of the latest DTN/The Progressive Farmer Agriculture Confidence Index. But that doesn't mean it's all good news.

The bad news from the index is about producers' worries over falling prices and a possible slowdown in the sales of agribusiness products.

"When it comes to overall expectations for the future, the index shows signs of some confidence," said Katie Micik, an editor at DTN/The Progressive Farmer and director of the confidence index.

"But we see that crop producers are worried over their future, especially about likely falling corn prices from overstocked corn," she said in a phone call with CNBC. "They're somewhat pessimistic."

Conducted since 2010, the index measures the sentiments of 500 agriculture producers. Farmers are also asked to rate current and long-term input prices and net farm income and their sentiments on the future.

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In the index, producers' overall confidence remained somewhat positive at 106.9, up slightly from 105.5 last December and unchanged from March 2013. The value of 100 is considered neutral. Values above 100 indicate optimism, whereas values below signify pessimism.

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Driven by higher meat prices and lower input costs, livestock producers' confidence rose to a near all-time high of 116.4, up from 107.5 last March and off just 0.2 from the record set in September 2010.

In addition, livestock producers view their present situation as very positive (145.1) even though they were considerably less optimistic for the upcoming year (97.3).

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But crop producers' confidence plummeted to the lowest level in four years, to 102.7 from 106.8 in March 2013—a reflection of worries over falling corn and soybean prices, even as current prices are at a higher level than what analysts had anticipated at this time of the year, according to Micik.

Agribusiness confidence climbed to 107.3 in March from 102.5 at the end of 2013, due in large part to stabilized crop prices. Seventy-two percent of agribusinesses surveyed felt good about their current sales, marking an increase of 14.6 percent since December and a 12 percent increase since last March.

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However, 76 percent of those agribusinesses believed sales expectations over the next 12 months will remain the same or get worse. In the survey, Micik found that fertilizer retailers were concerned that reductions in corn planting, due to overstocking, could affect sales and profits.