Adaptive responses of comammox Nitrospira and canonical ammonia oxidizers to long-term fertilizations: Implications for the relative contributions of different ammonia oxidizers to soil nitrogen cycling

Abstract

The new discovery of complete ammonia oxidizers (comammox), single organisms capable of oxidizing ammonia into nitrate, redefined the traditional view of nitrification. However, little is known about the relative contributions of comammox and other nitrifiers to nitrification, particularly in agricultural soils with long-term intensive input of nutrients. Herein, we investigated the communities of ammonia-oxidizing bacteria (AOB), ammonia-oxidizing archaea (AOA) and comammox Nitrospira in agricultural soils under nutrients input gradient of nitrogen (0–675 kg N ha −1 year −1 ), phosphorus (0–405 kg P 2 O 5 ha −1 year −1 ), and potassium (0–675 kg K 2 O ha −1 year −1 ) fertilizers for 19 year..