Identify one primary legislation or policy guiding nutrient management in Ontario.

The Nutrient Management Act (NMA) is a primary piece of legislation specifically designed to regulate nutrient management practices in Ontario. Enacted to address concerns about nutrient application on land, particularly from agricultural sources, the NMA aims to prevent the pollution of water resources while promoting sustainable agricultural practices. It sets out requirements for nutrient management plans, application standards, and the proper handling of nutrients, ensuring that farmers manage their nutrient applications responsibly and in accordance with environmental protection standards.

This act is central to the regulation of how nutrients, particularly fertilizers and manure, are applied and managed in agricultural settings, making it vital for both the agricultural community and the protection of water quality. Regulations established under the NMA ensure that nutrient management planning is integrated with broader environmental management efforts, reinforcing its significance as the guiding legislative framework for nutrient management in Ontario.