A key scheme to encourage Northern Ireland's farmers to manage land with the environment in mind is to be opened next spring.
However, it will not benefit from a government guarantee on its funding.
The Environmental Farming Scheme is due to open for applications in February.
But Agriculture Minister Michelle McIlveen has said it is not covered by the chancellor's promise to fully fund European Union schemes signed off before his Autumn Statement.
The scheme is part of Northern Ireland's rural development project which draws on EU funding.
Ms McIlveen said although the guarantee would not apply, she was intent on "securing the funding and implementing a well-focused scheme".
Previous agri-environment schemes made payments to farmers who worked to encourage biodiversity, enhance the landscape, and improve the quality of water, air and soil.
They were worth £180m over a seven-year term.
They finished in 2013 and the new one was being developed as part of the 2014-2020 rural development plan.
Plastic bag tax
In August, Chancellor Philip Hammond said all structural and investment fund projects, including agri-environment schemes signed before the Autumn Statement would be fully funded.
He said that would apply even when projects continued beyond the UK's departure from the EU.
Ms McIlveen also announced a funding boost for some environmental projects.
Nineteen groups will share an extra £500,000 to improve habitats and protect wildlife.
The money comes from the plastic bag tax and tops up grants of more than £3m made to almost 40 projects earlier this year.