(Dow Jones) -- A plurality of US agricultural producers expect a trade war to turn out badly for the farm sector, according to a survey by Purdue University and futures exchange operator CME Group. Asked whether a trade war would "significantly reduce" US farm exports, 47% of farmers surveyed said it was likely, with about one-fourth neutral on the prospect and 28% figuring no downside. Building concerns on trade come as the Purdue/CME measure indicates farmers' overall sentiment soured in March, with more deeming now a bad time to invest in new buildings and machinery.