There was a minor bump in the road this month for America's rural economy, but experts worry that a trade war could make things a whole lot worse.

Creighton University's Rural Mainstreet Index came in at 56.1 in June. While that's a slight dip from May's 56.3, the good news is that the index is now above growth-neutral (50.0) for five consecutive months. It's also an improvement from the 50.0 reading a year ago.

But there could be dark clouds on the horizon.

"Surveys over the past several months indicate the Rural Mainstreet economy is trending upward with improving, and positive economic growth. However, the negative impacts of recent trade skirmishes [have] yet to show up in our survey results. While agriculture commodity prices have improved recently, prices remain below breakeven for a large share of grain farmers," said Ernie Goss, economics professor at Creighton's Heider College of Business.

Indeed, the confidence index, reflecting expectations for the economy six months out, fell to 48.8 from May's 50.0. That indicates declining economic optimism among bankers such as Dan Coup, CEO of the First National Bank in Hope, Kansas.

"Price prospects for grain are a big concern with the trade war talks with China and other countries," said Coup, one of the community bank leaders in a 10-state region surveyed for the index.

And Goss noted that "just as last month, an unresolved North America Free Trade Agreement (NAFTA) and rising trade tensions with China continue to be a concern."

June's employment gauge improved to 58.0 from May's 56.0. "The Rural Mainstreet economy is now experiencing positive year-over-year job growth with added jobs at a 0.9 percent pace over the past 12 months compared to a slightly higher 1 percent for urban areas of the region," the report noted, though "both job growth readings are below U.S. job growth over the same period of time."

The farmland and ranchland-price index remains below growth-neutral for the 55th consecutive month. The 42.7 June reading is, however, an improvement on May's 42.2.

And as borrowing by farmers increased in June, 64 percent of bankers indicated they had increased collateral requirements on farm loans. Additionally, 40 percent indicated their bank rejected a higher percentage of farm loan applications.