Linking soil profile N2O concentration with surface flux in a cotton field under drip fertigation

Yanyan Li; Xiaopeng Gao; Mario Tenuta; Dongwei Gui; Xiangyi Li; Fanjiang Zeng

doi:10.1016/j.envpol.2021.117458

Linking soil profile N₂O concentration with surface flux in a cotton field under drip fertigation

Environ Pollut. 2021 Sep 15:285:117458. doi: 10.1016/j.envpol.2021.117458. Epub 2021 May 27.

Authors

Yanyan Li¹, Xiaopeng Gao², Mario Tenuta³, Dongwei Gui⁴, Xiangyi Li⁴, Fanjiang Zeng⁴

Affiliations

¹ State Key Laboratory of Desert and Oasis Ecology, Xinjiang Institute of Ecology and Geography, Chinese Academy of Sciences, Urumqi, 830011, China; Department of Soil Science, University of Manitoba, Winnipeg, MB, R3T 2N2, Canada; Xinjiang Key Laboratory of Desert Plant Roots Ecology and Vegetation Restoration, & Cele National Station of Observation and Research for Desert-Grassland Ecosystem, Xinjiang Institute of Ecology and Geography, Chinese Academy of Sciences, Cele, 848300, China; University of Chinese Academy of Sciences, Beijing, 100049, China.
² Department of Soil Science, University of Manitoba, Winnipeg, MB, R3T 2N2, Canada. Electronic address: xiaopeng.gao@umanitoba.ca.
³ Department of Soil Science, University of Manitoba, Winnipeg, MB, R3T 2N2, Canada.
⁴ State Key Laboratory of Desert and Oasis Ecology, Xinjiang Institute of Ecology and Geography, Chinese Academy of Sciences, Urumqi, 830011, China; Xinjiang Key Laboratory of Desert Plant Roots Ecology and Vegetation Restoration, & Cele National Station of Observation and Research for Desert-Grassland Ecosystem, Xinjiang Institute of Ecology and Geography, Chinese Academy of Sciences, Cele, 848300, China; University of Chinese Academy of Sciences, Beijing, 100049, China.

PMID: 34098458
DOI: 10.1016/j.envpol.2021.117458

Abstract

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. A plot-based field study was performed in 2017 and 2018 in a cotton field in arid northwestern China, with an objective 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. The in-situ N₂O concentrations at soil depths of 5, 15, 30 and 60 cm were measured and used to estimate soil profile N₂O effluxes. Estimates of surface N₂O flux using the concentration gradient-based (GM) were compared with those measured using the chamber-based (CM) method. In both years, soil N₂O concentrations at all depths increased in response to basal N application at planting or in-season fertigation events. However, 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 0-15 cm. Surface N₂O efflux determined by 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. These results highlight the challenge of applying the enhanced efficiency N fertilizer products in the drip-fertigated agricultural system.

Keywords: Concentration-gradient method; Drip fertigation; Enhanced efficiency fertilizers; Nitrification inhibitor; Profile N(2)O concentration.

MeSH terms

Agriculture
China
Fertilizers / analysis
Nitrogen / analysis
Nitrous Oxide* / analysis
Soil*

Substances

Fertilizers
Soil
Nitrous Oxide
Nitrogen