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Create a Complete Organic Fertilizer with confidence!

Sometimes it isn’t practical to get a soil test and build a custom fertilizer recipe using OrganiCalc. This is where a Complete Organic Fertilizer, or COF, can make a big difference.

This calculator makes it easy to build a COF using a variety of different inputs. It keeps track of your cost and calculates it on a per pound basis including extras like the cost of mixing, so you can quickly see which ingredients are driving the cost. Macronutrients which tend to be bulky are separate from the micronutrients so these may be mixed separately if you desire.

How to use the COF Calculator
  1. Enter your COF components and their listed nutrient content. Include the cost per pound and any notes (e.g. the supplier) if that is useful to you. It’s okay to enter amendments with no nutritive value, such as humates; they will be included in the recipe.
  2. Enter your target lbs/acre for N, P2O5, K2O, Ca, Mg or S. You don’t need to enter all of these, but N, P2O5 and K2O are helpful.
  3. Enter the area you want to amend, assuming a 6″ deep furrow slice.
  4. Enter the estimated weight of each of the COF components and adjust the weights until the mix is balanced and meets the targets. There are hints as to which nutrients need to be increased or decreased to achieve balance.
  5. A simple version of the recipe is on a separate page. On that page you can adjust the overall amount of the mix.
  6. If you want a micronutrient recipe too, open the COF micronutrient calculator tab. Enter your target lbs/acre for micronutrients. If you want a filler such as compost, enter that too.
  7. Email yourself a pdf of the completed recipe.

Complete Organic Fertilizer Calculator is available with an OrganiCalc Pro subscription

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