Important Note

Tufts ended funding for its Open Courseware initiative in 2014. We are now planning to retire this site on June 30, 2018. Content will be available for Tufts contributors after that date. If you have any questions about this please write to

Tufts OpenCourseware
Authors: Kathleen Merrigan, Ph.D., William Lockeretz, Ph.D.


  • National Research Council. Soil and Water Quality: An Agenda for Agriculture. Chapter 11. Manure and nutrient management. 1993.
  • University of Minnesota. Hog manure: Gunk or gold? no date.

Key Questions

Nitrogen Export from Agricultural Landscapes

  • What factors influence the export of plant nutrients from agricultural fields?
  • In which form is nitrogen mostly exported from the farms? What are the reasons?
  • What are the different options available for a farmer to prevent nutrient loss from his farm?
  • Can you think of additional factors that a farmer might consider before adopting any of these measures?
  • How do water bodies – artificially constructed or natural – help in the management of nutrients that are exported from the farms?

Costs and Benefits of Decreasing Agricultural Nutrient Export

  • What are the advantages of reducing nutrient loading of water bodies because of fertilizer usage in agriculture?
  • What does a farmer look for while considering the best management practice ( BMP) which might reduce agricultural related water degradation?
  • What is the trade-off involved while modifying agricultural ( especially N usage) practices to enhance water quality?
  • Is public opinion supportive of the farmers in relation to the hypoxia problem in the Gulf of Mexico, even though farming is a major source of the problem?
  • Which conservation policies we are familiar with from ASPI would be relevant in the context of reducing nutrient flow from farms?

Manure and Nutrient Management

  • Why is manure, once considered a resource now termed as waste?
  • What are the advantages of manure application in farming?
  • What is the pattern of nitrogen release from manure?
  • How can manure application lead to imbalance in the amount of phosphorus supplied to the soils? Why is this important?
  • Which agency regulates manure production and disposal of manure from point sources?
  • Do EPA regulations provide adequate protection to both surface and ground water pollution risks from manure produced at point sources?
  • What are some factors to consider while evaluating manure management from point and nonpoint sources?
  • What are the recommendations of the authors for environmentally safe management of manure?
  • What are the alternative uses of manure?
  • How does manure application affect crop yield?