By Christopher Doering

WASHINGTON, Feb 4 (Reuters) - There are nearly 76,000 more U.S. farms than a few years ago but new operations tend to be smaller, more diversified and have lower sales than the average farm, according to Agriculture Department data released on Wednesday.

A USDA census taken every five years found 4 percent more farms in 2007 than in 2002. There were fewer middle-size farms and markedly more farms that were small or very large.

"I don't think it's just a statistical anomaly that smaller farms have increased in number," Agriculture Secretary Tom Vilsack told USDA employees.

He said the increase was largely the result of efforts to encourage organic farming, boost land stewardship, improve productivity per acre and create opportunities in development of renewable energy.

"All of that suggests the chance for profitability," said Vilsack.

Overall, there were 2,204,792 farms in the United States, a net increase of 75,810 farms since the 2002 census.

The number of smaller farms with sales of less than $2,500, rose by 73,769 to 900,327 while large farms with sales of $100,000 or higher increased by 45,771 to 357,159 from 2002 to 2007.

While Vilsack noted the favorable increase among small and large farmers, he said he was "deeply concerned" about the drop among middle-sized operations. Operations generating income between $2,500 and $99,999 all posted declines in the number of farms compared to 2002.