NPK stands for Nitrogen (N), Phosphorus (P) and Potassium (K), which are the three macro nutrients that plants need to survive. Every fertilizer has an NPK rating which represents the percentage compositions of these three elements.
Most organic material contains trace amounts of these nutrients, but usually not in a form that is consumable by plants. The process of composting allows bacteria to digest organic material into small, water-soluble molecules that plants can consume.
This database attempts to compile an exhaustive list of the NPK values of every organic material that one might add to their compost mix.
There are a number of ways to use this database, not necessarily limited to the ones listed here.
It's important to balance the composition of macronutrients in your compost. This database can be used to help you decide what material to add to ensure that your compost remains balanced. For example, if you know your mix currently has an overabundance of potassium and you're considering adding a bucket of banana peels, after consulting this database, perhaps you'll reconsider.
It can be useful to know the macronutrient composition of your compost materials. If you keep track of the amount of each material you add to your compost mix, you can track the theoretical cumulative ratio of your compost mix. For example, if you add 1 kg of a 1-0-2 material, and 2 kg of a 0-2-3 material to your compost, the cumulative ratio comes out to be about 0.03-1.3-2.7.
If you have a tool to measure the NPK ratio of your compost, you can determine the maturity of your compost mix by comparing this measurement to your theoretical cumulative ratio.
If the two numbers are similar, then it is likely that your compost mix has reached maturity, because it means the nutrients have been processed in to a water soluble form. On the other hand, if your measured value differs significantly from your theoretical value, this indicates that your compost has not yet reached maturity.
This data has been compiled through web scraping and data mining methods from various sources on the internet. We aim to purchase equipment that allows us to generate our own NPK data to fill in missing gaps and verify existing data.