AgriSuite: Organic Amendment Calculator

Which field needs the nutrients or organic matter most?




Balancing your crop’s fertility needs is complex. Let AgriSuite help you make decisions. 

Applying nutrients to economically meet crop needs can be challenging, especially when manure or other organic amendments make up a portion of those nutrients. Since nutrients from organic sources don’t come in pre-determined blends, this calculator takes sample analysis information and combines rate, timing and placement of application to determine a best estimate of available nutrients. Combined with other calculators within AgriSuite farmers can determine additional fertilizer needs or when excess nutrients could risk environmental losses.

 AgriSuite is an interactive online collection of management tools and calculators, developed by OMAFRA that you can access from your desktop or mobile device. AgriSuite assists you with key crop fertilization management decisions and how they relate to optimizing crop production and protecting the environment.
AgriSuite – The Organic Amendment Calculator helps determine nutrients supplied from manure inputs.
This tool will calculate the amount of crop-available nutrients ((N-P-K) and applied micronutrients) for each proposed application of organic amendments. An estimate of fertilizer equivalent value of manure N-P-K after application is also provided. provides an overview of the organic amendment calculator.  A step-by-step walk through the calculator is provided at 

  • The Organic Amendment calculator provides an estimate of available nutrients from manure or other organic sources.  With analysis or database values for common livestock species and management decisions around timing, placement, incorporation and rate, the calculator provides estimates for available N-P-K, total micronutrients applied and and an estimated dollar value after application.

    The Organic Amendment Calculator will help you manage your soil fertility because it:
  • Estimates nutrients applied to a crop
  • Gives a guideline for additional commercial fertilizer require to balance crop needs
  • Provides a quick comparison of impacts of different timing or placement scenarios

    Other AgriSuite calculators that can help with your crop fertility needs are:
  • Crop Nutrient calculator to determine crop needs and nutrient removal
  • the Fertilizer calculator to determine inorganic fertilizer applied or blends to meet crop requirements
  • the Phosphorus Loss Assessment Tool for Ontario (PLATO) to help minimize phosphorus loss from individual fields
  • the Field Management Calculator which incorporates the individual tools to allow nutrient balancing for individual crops or crop rotations
This project was funded in part through the Canadian Agricultural Partnership (the Partnership), a federal-provincial-territorial initiative