Can coir and soil be mixed

Can do any ratio, but the more coir you put in the more its becomes less soil and more soilless despite there being some soil in it. I'd work in anywhere from 30-50% but also add in around 10-20% perlite. I like coir but it has its own set of challenges and a CaMg supplement should be used if it goes over 30% My deck pots are a mix of coir and soil + other things, it works out well. Good Luck!