Nitrifying Organisms Affected by Climatic Region in Western United States

Abstract

Abstract Nitrification of ammoniacal (NH 4 + ) N added as (NH 4 ) 2 SO 4 to different soils of western USA and incubated at 20, 25, 35 and 40C with moisture at 0.3 bar moisture tension was investigated. In all soils from northern regions, nitrification was faster at 20 and 25C than at 35 and 40C. The reverse was true in the case of the southern soils which nitrified fastest at 35C. Nitrites accumulated in larger quantities under the temperature conditions less favorable for nitrification.