Soil Bacteria and Phosphates

1. Nitrite bacteria make phosphorus and calcium soluble from insoluble phosphates when they oxidize or convert ammonia into nitrite. 2. The actual ratio found shows that about one pound of phosphorus and about two pounds of calcium are made soluble for each pound of nitrogen oxidized, aside from the action of the acid radicles associated with the ammonia. 3. The ratio of solubility found on the basis of nitrogen to phosphorus and calcium conforms to the following reaction: [Note: See the image of page 249 for this formatted text] 4HNO2 + Ca3(PO4)2 = CaH4(PO4)2 + 2Ca(NO2)2. According to this equation, 56 pounds of nitrogen liberate in soluble form 62 pounds of phosphorus and 120 pounds of calcium. 4. Neither ammonia-producing bacteria nor nitrate bacteria liberate appreciable amounts of soluble phosphorus from insoluble phosphates. More complete details of these experiments will be published in Bulletin No. 190 of the University of Illinois Agricultural Experiment Station.