The county's Crop Circle Information and Coordination Centre (CICC) said they had only seen 25 so far this year - 15 fewer than usual for the period.
A decline in the man-made act and a late harvest have both been blamed.
Charles Mallet, from the centre, said he wished amateur crop circlers would quit because they were "clouding a genuine and real phenomenon".
He said: "The whole situation has become massively polluted over the last 10 years or so, to the degree where the real issue is clouded by huge amounts of organised crime and vandalism.
"These people are effectively creeping onto private land and vandalising it. Farmers are extremely angry about this."
In a bid to appease landowners, the centre has backed a crowd-funding campaign to sell "access passes" with money raised going towards compensating affected farmers.
So far it has raised about Â£1,900 towards a targeted Â£35,600.
Derren Heath, landlord of the Barge Inn near Pewsey, said local businesses depended on tourists coming to see the crop circles.
He added that tourists would spend time in the area to also visit the stone circles in Stonehenge and Avebury as well as West Kennet Long Barrow and Silbury Hill.
"We have had visitors from Norway, France, Spain in the last year - from everywhere in the world they come here," he said.
"They are going to stay here for a week and take in absolutely everything, so it brings a massive amount of money into the area."
But man-made crop circles are often unpopular among the landowners who have their crops targeted.
Ben Butler, a farmer from Avebury, said hundreds of pounds of damage was being done to his land every year.
"Farming over the last 12 months has been very hard due to the weather, so the crops were not established well last autumn, and now we've got criminal damage in the field," he said.
"Probably over the last 20 years we would see at least two formations on our farm every year.
"What that brings is the issue of people entering your field - nobody asks, they just come as they like.
"I wouldn't walk into someone's garden without asking so why should they be allowed to walk in the field without asking."
Crop circle appearances in Wiltshire have dropped by almost half in a year, according to researchers.