Influences of shallow groundwater depth on N2O diffusion along the soil profile of summer maize fields in North China Plain

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The emissions of nitrous oxide (N2O) from agricultural fields are a significant contribution to global warming. Understanding the mechanisms of N2O emissions from agricultural fields is essential for the development of N2O emission mitigation strategies. Currently, there are extensive studies on N2O emissions on the surface of agricultural soils, while studies on N2O fluxes at the interface between the saturated and unsaturated zones (ISU) are limited. Uncertainties exist regarding N2O emissions from the soil-shallow groundwater systems in agricultural fields. In this study, a three-year lysimeter experiment (2019-2020, 2022) was conducted to simulate the soil-shallow groundwater systems under four controlled shallow groundwater depth (SGD) (i.e., SGD = 40, 70, 110, and 150 cm) conditions in North China Plain (NCP). Weekly continuous monitoring of N2O emissions from soil surface, N2O concentration in the shallow groundwater and the upper 10 cm of pores at the ISU, and nitrogen cycling-related parameters in the soil and groundwater was conducted. The results showed that soil surface N2O emissions increased with decreased shallow groundwater depth, and the highest emissions of 96.44 kg ha-1 and 104.32 kg ha-1 were observed at G2 (SGD = 40 cm) in 2020 and 2022. During the observation period of one maize growing season, shallow groundwater acted as a sink for the unsaturated zone when the groundwater depth was 40 cm, 70 cm, and 110 cm. However, when SGD was 150 cm, shallow groundwater became a source for the unsaturated zone. After fertilization, the groundwater in all treatment plots behaved as a sink for the unsaturated zone, and the diffusion intensity decreased with increasing SGD. The results would provide a theoretical basis for cropland water management to reduce N2O emissions.

Medienart:

E-Artikel

Erscheinungsjahr:

2024

Erschienen:

2024

Enthalten in:

Zur Gesamtaufnahme - volume:926

Enthalten in:

The Science of the total environment - 926(2024) vom: 20. Apr., Seite 171861

Sprache:

Englisch

Beteiligte Personen:

Li, Zhao [VerfasserIn]
Li, Xurun [VerfasserIn]
Zhang, Qiuying [VerfasserIn]
Li, Fadong [VerfasserIn]
Qiao, Yunfeng [VerfasserIn]
Liu, Shanbao [VerfasserIn]
Leng, Peifang [VerfasserIn]
Tian, Chao [VerfasserIn]
Chen, Gang [VerfasserIn]
Cheng, Hefa [VerfasserIn]

Links:

Volltext

Themen:

Journal Article
Lysimeter
Nitrous oxide (N(2)O)
North China plain (NCP)
Shallow groundwater depth (SGD)
Soil profile
Summer maize field

Anmerkungen:

Date Revised 16.04.2024

published: Print-Electronic

Citation Status PubMed-not-MEDLINE

doi:

10.1016/j.scitotenv.2024.171861

funding:

Förderinstitution / Projekttitel:

PPN (Katalog-ID):

NLM370083865