1. Introduction
Nitrogen accumulation in Inner Mongolia of China is increasing
in many soils which mainly results from nitrogen fertilization
accompanied with conversion of large area of grasslands to croplands.
Nitrification is a central process for nitrogen cycle and plays
important roles in soil nutrient and nitrate pollution which is
mainly driven by microorganisms, yet the effects of nitrogen accumulation
on nitrification and related microorganisms have not
been well studied in Inner Mongolia