I've been making my own compost for the last 4 years, I have three large 1m.sq bins made from wooden palets so am able to use each bin every 2 years. My mix is made up of kitchen veg waste, grass clipings and green leafy waste from the garden including weeds and (perennial weeds which I soak in water for about 4 weeks before adding), also comfrey leaves, cardboard boses and at least 6 scrunched up sheets of newspaper everyday which is taken from the base of my two large parrot cages so they contain parrot poo and discarded fruit. I turn this mix every time I add stuff and you can feel the heat generated in it as I fork it.
I recently tested this mix because I have had such little success with growing produce. The test result show low and extremely low in all of the test for NKP -, why? What am I doing wrong?