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Peer Review

Nitrogen in the Environment



Overall Numeric Rating:

3.8 stars
Content Quality: 3.3 stars
Effectiveness: 3 stars
Ease of Use: 5 stars
Reviewed: Mar 09, 2004 by Biology Editorial Board

A clear presentation of the movement of nitrogen through an ecosystem from the University of Missouri at Columbia Extension Service. Page includes both simplified and more detailed illustrations of the cycle that would be useful at different grade levels from elementary to freshman in college. There is also a description of how nitrogen is added to and lost from the cycle as well as impacts on the environment as excess nitrogen moves into the watershed. Two figures are provided along with links from the water quality initiative as well as links to education, research, and services published by MU Extension. There are several links to more detailed information on specific aspects of the basic cycle such as denitrification, immobilization and leaching. The site meets the needs of the expected users.

Type of Material:

Most of the information is presented as a collection/database in HTML.

Recommended Uses:

Depending on the level of class, the site could serve as a basic, simplified introduction using Figure 1 or a more comprehensive treatment for high school and freshman college level biology making use of additional links provided.

Technical Requirements:

Basic site requires only current internet browser.

Identify Major Learning Goals:

Students will gain a basic understanding of the nitrogen cycle and how it relates to environmental quality.

Target Student Population:

This site is targeted for the general public as well as high school and college students.

Prerequisite Knowledge or Skills:

As part of an extension service, the site is targeted to agricultural and landscape businesses. It does not assume a great deal of knowledge of ecosystems, although some understanding of general chemistry will help users understand the material. Use of web browser will be required.

Evaluation and Observation

Content Quality

Rating: 3.3 stars

  • Clear, accurate description of most aspects of the nitrogen cycle.
  • Level of detail is appropriate for the target audience.
  • Interactive and engaging layout.
  • Shows how nitrogen cycle relates to environmental quality.

  • Some of the linked pages that provide additional information are too abbreviated. More detail would be useful in these links.
  • There are some over-generalizations about the nitrogen cycle, although this is explained in the text.
  • Figure 2 is a more comprehensive illustration of the cycle but does not cover all possible ways nitrogen moves in cycle.
  • Some information is well presented, particularly as it relates to environmental quality, but other parts of the text are not quite as easy to understand.

Potential Effectiveness as a Teaching Tool

Rating: 3 stars

  • Provides good background information on the nitrogen cycle as it relates to environmental quality.
  • Illustrations suitable for both simplified and more comprehensive presentations of this material.
  • Several links provided to more comprehensive presentations on specific aspects of the cycle.
  • Assignments could be built around the information presented.


  • The detailed approach to the nitrogen cycle is not necessarily complete and may require additional instruction to completely understand the processes involved
  • Not designed to encourage interactivity or problem solving.

Ease of Use for Both Students and Faculty

Rating: 5 stars

  • This is a one-page HTML learning object and very easy to navigate
  • List of topics in right margins clearly shows what page covers.
  • All links functional; no major bugs found.
  • Written for user with minimal biology background?little jargon used.


  • May not be detailed enough for all users.

Other Issues and Comments:

The site will be generally useful up through introductory biology, especially from an environmental quality perspective. Above that level, the site will not provide sufficient detail but would serve as a basic review. The most useful part of this page includes the two figures at the bottom showing an overview and a more detailed depiction of the nitrogen cycle. The site accurately meets the needs of the target audience.