Effects of long-term n fertilizer application and liming on nitrification and ammonia oxidizers in acidic soils

Abstract

High levels of N fertilization and acid deposition could cause soil acidification directly and indirectly. The nitrogen cycle, especially nitrification, makes a great contribution to the acidification of agricultural soils across China, which further leads to the mobilization of potentially toxic metals such as aluminum (Al) and manganese (Mn) and decerases crop yields. Chemicals (e.g., CaO) are amended as soil conditioners to relieve soil acidification. Ammonia oxidation, the rate-limiting step in the nitrification process, is driven by ammonia-oxidizing bacteria (AOB) and ammonia-oxidizing archaea (AOA). Increasing evidence demonstrates that pH is one of the most important factors determin..