HS Codes for liquid fertiliser for use in agriculture

If it contains only the fertilising elements N, it is 31.02, if the fertilising element P only, it is 31.03, it contains K only it is 31.04. If the product is a mixture of two or all the 3 fertilising elements, it is 31.05. If it does not contain substantial amount of above fertilising elements, it should be 3824.90.