Study Reveals How Nitrogen Fertilizer Management Affects Soil Profile N2O Concentration and Surface Flux
An international team led by researchers from the Xinjiang Institute of Ecology and Geography (XIEG) of the Chinese Academy of Sciences and the University of Manitoba revealed the effect of nitrogen (N) fertilizer management on N2O concentration and surface flux.
Agricultural soil N2O surface emissions are determined by its production, diffusion, and consumption along soil profile, which can be strongly influenced by N fertilizer management. Drip fertigation is a widely used strategy in arid and semi-arid climate regions for the benefits of saving irrigation water and increasing fertilizer use efficiency.
It remains unclear how the source and rate of nitrogen (N) fertilizers affect N2O concentration and effluxes along the soil profile under the drip-fertigated agricultural system.
The researchers carried out an experiment in a cotton field in arid northwestern China from 2017 to 2018 to elucidate the impact of the applications of conventional urea (Urea), polymer-coated urea (ESN) and stabilized urea (SuperU) at rates of 120 and 240 kg N ha-1 on concentration and efflux of N2O in the soil profile and its relationship with N2O surface emissions.
Results showed that N rate or source did not affect soil N2O concentrations or effluxes at each depth. Surface emissions of N2O were mostly associated with that presented in the top layer of 0-5 cm.
Surface N2O efflux determined by gradient-based (GM) was poorly or not associated with those of chamber measurements, which was attributed to the low N2O production restricted by soil moisture condition under the drip-fertigated condition.
The study was published in Environmental Pollution.
Contact: LIU Jie, Xinjiang Institute of Ecology and Geography