Effects of irrigation methods and salinity on CO2 emissions from farmland soil during growth and fallow periods

Chenchen Wei; Shumei Ren; Peiling Yang; Yu Wang; Xin He; Ziang Xu; Rong Wei; Shuaijie Wang; Yanbing Chi; Meitao Zhang

doi:10.1016/j.scitotenv.2020.141639

Effects of irrigation methods and salinity on CO₂ emissions from farmland soil during growth and fallow periods

Sci Total Environ. 2021 Jan 15:752:141639. doi: 10.1016/j.scitotenv.2020.141639. Epub 2020 Aug 15.

Authors

Chenchen Wei¹, Shumei Ren¹, Peiling Yang², Yu Wang¹, Xin He¹, Ziang Xu¹, Rong Wei¹, Shuaijie Wang³, Yanbing Chi¹, Meitao Zhang¹

Affiliations

¹ College of Water Resources and Civil Engineering, China Agricultural University, Beijing 100083, China.
² College of Water Resources and Civil Engineering, China Agricultural University, Beijing 100083, China. Electronic address: yang-pl@163.com.
³ College of Water Resources and Civil Engineering, China Agricultural University, Beijing 100083, China; Henan Water Conservancy Survey, Ltd., Zhengzhou 450000, China.

PMID: 32890824
DOI: 10.1016/j.scitotenv.2020.141639

Abstract

Drip irrigation and brackish water irrigation are considered to be the two main ways to alleviate the current shortage of agricultural freshwater resources and have been widely used in countries around the world. Our purpose is to evaluate the effects of different irrigation methods (flood irrigation and drip irrigation) and irrigation water salinities (1.1 g·L^-1, 2.0 g·L^-1, 3.5 g·L^-1, and 5.0 g·L^-1) on the soil CO₂ emissions during the growth and fallow periods of spring maize. Therefore, a two-year field experiment was conducted in Hetao Irrigation District in China from 2017 to 2019. The results showed that compared with flood irrigation, drip irrigation significantly decreased the soil CO₂ emissions in the growth period. After irrigation with a salinity of 5.0 g·L^-1, the soil moisture was the highest because the plant water absorption was inhabited by soil salt, and the soil CO₂ emissions were also promoted during the growth period. Irrigation method and irrigation water salinity had no effect on the soil CO₂ emissions in the fallow period. Soil temperature, moisture and inorganic nitrogen content were the main factors affecting the daily CO₂ emission flux. The soil CO₂ emissions during the growth period accounted for more than 83.93% of the annual soil emissions. Based on the goal of saving freshwater resources, ensuring soil safety, reducing soil CO₂ emissions and increasing the size of the carbon pool, adoption of drip irrigation with 2.0 g·L^-1 brackish water could be adopted to ensure the sustainable development of local agriculture.

Keywords: Brackish water; Drip irrigation; Hetao Irrigation District; Maize growth; Soil CO(2) emissions; Soil properties.