Ravensdown is no longer using trains for its Napier plant, meaning more trucks will use Marine Parade in spring and autumn ferrying fertiliser from Napier Port.
Communications manager Gareth Richards said for the last three years 85 per cent of product shipped from the Awatoto plant was freighted by road or coastal ship and the cessation of rail was an amicable agreement.
The farmer-owned co-operative is the only user of the fertiliser carriages and KiwiRail proposed increased charges to cover upkeep.
"The issue for KiwiRail and Ravensdown is the very high expenditure associated with the maintenance of ageing rolling stock," he said.
"This led to KiwiRail proposing a rail freight rate that was just uneconomic. If more businesses had used the rail freight option over the years, then of course those maintenance costs would have been spread more evenly."