Nutrient Management Technical Service Provider Certification Act of 2018 This bill amends the Food Security Act of 1985 to provide alternative certification methods for third-party technical service providers (TSPs). (TSPs provide technical expertise to agricultural producers on behalf of the Department of Agriculture [USDA] Natural Resource Conservation Service to assist in planning and implementing conservation measures.) USDA must approve certain professional certifications that meet or exceed national criteria and were established by: the USDA, an agriculture-related retailer, a farmer cooperative, the American Society of Agronomy, or the National Alliance of Independent Crop Consultants. A qualified certification includes a certifications as: a Certified Crop Advisor by the American Society for Agronomy, a Certified Professional Agronomist by the American Society for Agronomy, and a Comprehensive Nutrient Management Plan Specialist by USDA.