Factors limiting denitrification in deep vadose zone

Microbes in subsurface soil, which is more broadly referred to as vadose zone,play an essential role in mitigation of nitrate leaching in agricultural areas where nitrogen fertilizer has been intensively applied. To gain insight into the mechanisms of microbial denitrification in vadose zone, we studied experimentally how organic carbon and dissolved oxygen affect the denitrification rate, functional gene abundance and microbial community structure along the soil profile down to 10.5 meters deep.The samples were taken from a long-term (~20 years) nitrogen fertilization experiment in China North Plain, which is one of the largest agricultural production area in China.