EFFECT OF PHOSPHATES ON NITRIFYING CAPACITY OF SOILS

Abstract

Phosphates in the presence of CaCOs in-creased nitrification of (NH4)2SO4 in several soils of low nitrifying capacity. The average order of effectiveness of phosphates to promote nitrification, beginning with the most effective, was: monopotassium phosphate, 20% superphosphate, dipotassium phosphate, monocalcium phosphate, tricalcium phosphate, dicalcium phosphate, disodium phosphate, rock phosphate, and soft phosphate with colloidal clay. The soils which respond to phosphates are low in active phosphoric acid and fair to high in lime and basicity.