Response of soil functional bacteria to nitrogen input

In order to deeply study the ecological process of Alpine soil, a simulated nitrogen deposition experiment was set up to analyze the changes of three nitrogen mineralization functional bacteria (ammonifying bacteria, nitrifying bacteria and denitrifying bacteria) in Western Sichuan Plateau soil. Three nitrogen input treatments were designed (CK, N0.1 and N0.4). The number of three functional flora in soil was calculated by MPN method (maximum probability counting method). The results showed that the number of ammonifying bacteria increased with the increase of nitrogen input, and increased by about 2.68 times and 3.1 times at N0.1 and N0.4 nitrogen input levels, respectively. The number of nitrifying bacteria also increased with the increase of nitrogen input, and increased by nearly 4 times and 3.7 times under the addition of N0.1 and N0.4, respectively. But the number of denitrifying bacteria decreased with the increase of nitrogen input, decreased by 17.17% and 15.42% respectively. The results show that nitrogen addition affects the number of different functional bacteria in soil to a certain extent, thus affecting soil fertility and soil microbial community structure.