It doesnt matter if its organic or 'chemical.' A plant can only absorb ions of elements (P,K,N) The soil acts as the the root systems stomach and breaks the organic matter to inorganic ions that can be absorbed through the plants cells that make up the roots. An organic molecule would be to big. In conlcusion, its all the same, except one can be taken up by the plant immediately and other has to wait until the soil microbes have broken it down. I use a mix of both now, after doing 'chems' and organics and its always the same. any differences are completely subjective.