This year Gwent Police saw its budget cut by 5%, resulting in a 30% cut in real terms over six years.
Mr Johnston has suggested that to tackle rural crime, such cuts have to stop.
The rural crime survey found that farmers and hard-pressed young families are the most frequent victims of crime, with the average cost to a household being over £2,500 and for a business over £4,000.
More than one in four victims did not report the crime, meaning Home Office figures of 294,000 rural crimes between April 2014 and May 2015 could be incorrect and the actual number of crimes could be as high as 403,000.
Gwent Police has been held up as a model of best practice by the NRCN due to its Farm Watch scheme that has led to a reduction of 27% in farm-related crime.
Mr Johnston said: “This survey has shown the cost and the scale of the challenges faced in policing our rural communities is unprecedented and has highlighted why it is important to maintain and improve services to them.
“We want to make sure our rural communities in Gwent are getting the quality of service they need and deserve and this can only be achieved with the police, partners and the Government working together to tackle certain issues.
“What this report has highlighted is that there are and will be further consequences if the Government continues with its policy of continued budget cuts to frontline policing.”
A Home Office spokesperson said: “Police reform is working and crime has fallen by more than a quarter over the last five years, according to the Independent Crime Survey for England and Wales. Overall, people in rural areas are two thirds as likely to be the victim of crime as those in urban areas.
“The election of Police and Crime Commissioners has given communities – including those in rural areas – a strong voice in determining how police resources are allocated to tackle the crimes that matter most to them.
“This Government welcomes the work the National Rural Crime Network is leading to ensure police forces respond to crime in rural areas with the same dedication as crime in urban areas. We trust reports like this will help PCCs hold their forces to account for the services they offer.”