Here is a list of the main NPK constituents of the more common fertilisers, both chemical and organic

  There have been many arguments, both for and against over the years for the use of organic over chemical fertilisers. It seems that it depends on who was your original teacher, as to which school of thought you adhere to.  However, as someone who has been carrying out scientific research in both biology and botany of one kind or another as a profession since 1963, I personally think both methods have their benefits.  In the right circumstances, for the right reasons, under the right conditions, for the correct species, using the correct regime, both have their place! However, it should be remembered that using organic fertilisers enables the growth of symbiotic fungi to flourish in the soil of your bonsai. Because they have the ability to break the different components of the organic fertiliser down to a usable form. This occurs far less, if at all with purely chemical fertilisers.