AGRICULTURE 
631.82 
B21 
822 
823 
83 
1831 
832 
833 
84 
R41 
843 
844 
845 
846 
847 
848 
85 
851 
852 
853 
854 
855 
QA 
87 
871 
872 
873 
874 
875 
876 
88 
0 
Mineral amendments 
Lime, gypsum, plaster 
Marl 
Sulfate of iron 
Potash fertilizers 
Wood ashes, vegetable ashes, burning turf 
Chlorids 
Sulfates 
Nitrogen fertilizers 
Ammonium salts 
Nitrates 
Calcium cyanamid 
Sewage 
Animal industry residues: skin, ete. 
Slaughter house refuse. See also 631.852 Bone 
Fish 
Blood 
Tankage 
Vegetable nitrogen fertilizers 
Cotton seed meal, castor beans, pomace 
Nitrifying crops 
Soil inoculation Bacteria Nitrification 
For soil conditions see 631.46. Here clas introduction of bacteria to 
improve the soil Difference is same as between 631.45 Soil fertility and 
631.8 Fertilizers 
Azotin, ammonite, etc. 
Fosforic acid 
Natural rock 
Bone 
Slags 
Guano 
Superfosfates 
Farmyard and stable manures, etc. 
Subdivided like 636; e. g. 631.862 Cow manure 
Vegetable manures 
Muck 
Leavs 
Seaweed 
Green manures 
Vegetable compost 
Residue from vegetable industries 
Fertilizer experiments 
Climate, roads, etc.