Dairy and livestock producers, farm advisors, and students preparing for careers in agriculture are increasingly seeking to understand and apply concepts of nutrient management for effective agricultural environmental management. Stimulated by a need for self-paced support materials for both the Whole Farm Nutrient Management class at Cornell University and the growing number of nutrient management planners in New York State, five web-based learning modules were developed, covering: (1) the Nitrogen Cycle and Crop Nitrogen Guidelines, (2) Manure Nitrogen, (3) Manure and Fertilizer Phosphorus Management, (4) the Phosphorus Runoff Index, and (5) Fertilizer Management. The modules guide users through the topic with text, photos, videos, web-based calculators, and quiz questions designed to provide immediate feedback to responses. The modules serve two major audiences: (1) an extension audience, including farmers, extension educators, and public- and private-sector farm advisors, and (2) the approximately 35 students taking the Whole Farm Nutrient Management class each spring. For the extension audience, the modules are accessible through the Nutrient Management Spear Program website (http://nmsp.css.cornell.edu). The site-map styled home page allows users to go through the modules from start to finish, or to navigate directly to a topic of interest. The student version is delivered through a Blackboard web interface. The learning modules serve as an interactive textbook to be used in preparation for upcoming lecture and computer laboratory sessions. Graded, online quizzes are paired with the modules to evaluate student performance and identify areas needing more attention during class hours. Five undergraduate students evaluated the modules in spring 2005. This evaluation showed that the modules stimulated student interest and were effective in improving understanding of concepts. The modules will be used with the entire Whole Farm Nutrient Management class in spring 2006.