| 71 / | HD | CHEMISTRY: FERTILIZERS |
| 1 | DF | PROCESSES AND PRODUCTS {5} |
| 31 | DF | .~ Inorganic material {5} |
| 32 | DF | .~.~ Phosphorus-containing {1} |
| 33 | DF | .~.~.~ Phosphates {6} |
| 48 | | .~.~.~.~ Products {4} |
| 49 | DF | .~.~.~.~.~> Nitrogen-containing {1} |
| 51 | DF | .~.~.~.~.~> Alkali metal- and ammonium-containing |
| 52 | DF | .~.~.~.~.~> Silicon-containing |
| 53 | DF | .~.~.~.~.~> Containing carbonates, oxides, sulfates, or halides |