The nation's small-business owners had a bleaker outlook on the economy in August, with many bracing for tougher credit conditions ahead, the National Small Business Association reported this week.

In a nationwide survey of 250 of its members, 79 percent said they are expecting flat growth or a recession  in the coming year, the Washington-based group said. Another 67 percent said the U.S. economy was worse off than it was five years ago, while just over half cited economic uncertainty as the top business challenge.

More owners were also worried about accessing bank loans, lines of credit and other sources of working capital, the survey found.

Sixty-seven percent of respondents said their businesses were affected by the credit crunch, up from 55 percent in a similar survey conducted in February.

"Small-business owners are feeling less confident in nearly every way, particularly with bank's ability to keep their money safe," Todd McCracken, the group's president, said in a statement.

At the same time, most owners said they remained confident about the future of their own business, the survey found.