Environmental indicators offer a simple measure of the status of an environmental attribute. Examples include indicators of potential damage, such as toxic emissions, as well as indicators of potential benefits, such as biodiversity. Environmental indicators can be used in trade-off analysis.

Introduction to Agro-Environmental Indicators
This helpful introduction to the general topic of environmental indicators for agriculture comes from Environment Canada.

Specific environmental indicators
Many different specific environmental indicators are available. This page provides links to indicators of soil erosion, pesticide toxicity, and other indicators.

The World Bank's "The Little Green Data Book" offers national and regional data extracted from its annual World Development Report with environmental information for all nations.

The Organization for Economic Cooperation and Development (OECD) in 2000 prepared a major report on "Environmental Indicators for Agriculture-Methods and Results." It covers environmental indicators for agriculture from field to landscape scale, including economic as well as biophysical indicators.

Tools for estimating the effects of water-caused soil erosion range from a single equation to a complex simulation model. Three major tools are:

1. Universal Soil Loss Equation (USLE) - This is the original and most widely used tool for estimating soil erosion without knowing location specific data.
   
   Robert P. Stone, Don Hilborn, Ministry of Agriculture and Food, Ontario, Canada
   
   
2. Revised Universal Soil Loss Equation (RUSLE) - A revised, updated version of the USLE.
   
   USDA, Agriculture Research Service, National Sedimentation Laboratory, the "official" U.S. Department of Agriculture (USDA) for RUSLE -
   
   Institute of Water Research (IWR),
   Michigan State University (MSU) - User-friendly site with data for Michigan.
   
   
3. Water Erosion Prediction Project (WEPP)
   WEPP model is a process-based, distributed parameter, continuous simulation, erosion prediction model. The current model version (v2004.600) available for download is applicable to hill slope erosion processes, as well as simulation of the hydrologic and erosion processes on small watersheds. (Purdue University).
   

Pesticide Toxicity Categories and Pesticide Label Statements
These have been organized by the U.S. Environmental Protection Agency (EPA) using criteria to classify pesticides by toxicity level.

Pesticide Topical & Chemical Fact Sheet, Assessing Health Risks from Pesticides
This EPA site explains how EPA calculates health risks from pesticides.

Pesticide Fact Sheets
National Pesticide Information Center (NPIC) Pesticide Fact Sheets provide general pesticide information, including toxicity profiles, organized by pesticide active ingredient name. (Oregon State University and EPA).

Pesticide Information Profiles (PIPs)
EXTOXNET (Extension Toxicology Network, UC- Davis). provides detailed information on pesticide toxicity, but less cleanly presented than the NPIC pesticide fact sheets.

Toxicology Information Briefs (TIBs)
TIBs explains toxicology information contained in the EXTOXNET Pesticide Information Profiles above.

Chemical and Pesticides Results Measures (CAPRM)
This Florida State University and EPA site offers fact sheets that explain various indicators of human health, ecological health, chemical & pesticide safety, food safety, and product safety.