Carryover Equity Act of 2018 This bill amends the National Agricultural Research, Extension, and Teaching Policy Act of 1977 to allow 1890 land-grant colleges and universities (historically black colleges and universities that were established under the Second Morrill Act of 1890 and receive funding from the Department of Agriculture) to carry over all extension funding into the succeeding fiscal year. (Under current law, the institutions are prohibited from carrying over more than 20% of the funds received in any fiscal year.)