Soil moisture determines effects of climates and soil properties on nitrogen cycling: Examination of arid and humid soils

Tianhui Lu; Jing Wang; Hansong Zhu; Zekun Zhong; Xiang Wang; Xiaoxu Jia; Mingan Shao; Xiaorong Wei

doi:10.1016/j.jenvman.2024.123831

Soil moisture determines effects of climates and soil properties on nitrogen cycling: Examination of arid and humid soils

J Environ Manage. 2025 Jan:373:123831. doi: 10.1016/j.jenvman.2024.123831. Epub 2024 Dec 30.

Authors

Tianhui Lu¹, Jing Wang², Hansong Zhu³, Zekun Zhong⁴, Xiang Wang⁵, Xiaoxu Jia⁶, Mingan Shao⁷, Xiaorong Wei⁸

Affiliations

¹ State Key Laboratory of Soil Erosion and Dryland Faming on the Loess Plateau, The Research Center of Soil and Water Conservation and Ecological Environment, Chinese Academy of Sciences and Ministry of Education, Yangling, Shaanxi, 712100, China; Institute of Soil and Water Conservation, Chinese Academy of Sciences and Ministry of Water Resources, Yangling, Shaanxi, 712100, China; University of Chinese Academy of Sciences, Beijing, 100049, China.
² Co-Innovation Center for Sustainable Forestry in Southern China, College of Forestry, Nanjing Forestry University, Nanjing, 210037, China.
³ State Key Laboratory of Soil Erosion and Dryland Faming on the Loess Plateau, Northwest A&F University, Yangling, Shaanxi, 712100, China; Wildlife Conservation Monitoring Center, National Forestry and Grassland Administration, Beijing, 100714, China.
⁴ State Key Laboratory of Soil Erosion and Dryland Faming on the Loess Plateau, Northwest A&F University, Yangling, Shaanxi, 712100, China.
⁵ College of Land Science and Technology, China Agricultural University, Beijing, 100049, China.
⁶ State Key Laboratory of Soil Erosion and Dryland Faming on the Loess Plateau, Northwest A&F University, Yangling, Shaanxi, 712100, China; Key Laboratory of Ecosystem Network Observation and Modeling, Institute of Geographic Sciences and Natural Resources Research, Chinese Academy of Sciences, Beijing, 100101, China.
⁷ State Key Laboratory of Soil Erosion and Dryland Faming on the Loess Plateau, The Research Center of Soil and Water Conservation and Ecological Environment, Chinese Academy of Sciences and Ministry of Education, Yangling, Shaanxi, 712100, China; State Key Laboratory of Soil Erosion and Dryland Faming on the Loess Plateau, Northwest A&F University, Yangling, Shaanxi, 712100, China; CAS Center for Excellence in Quaternary Science and Global Change, Xi'an, Shaanxi, 710061, China.
⁸ State Key Laboratory of Soil Erosion and Dryland Faming on the Loess Plateau, The Research Center of Soil and Water Conservation and Ecological Environment, Chinese Academy of Sciences and Ministry of Education, Yangling, Shaanxi, 712100, China; State Key Laboratory of Soil Erosion and Dryland Faming on the Loess Plateau, Northwest A&F University, Yangling, Shaanxi, 712100, China; CAS Center for Excellence in Quaternary Science and Global Change, Xi'an, Shaanxi, 710061, China. Electronic address: [email protected].

PMID: 39740459
DOI: 10.1016/j.jenvman.2024.123831

Abstract

While soil moisture has a significant effect on nitrogen (N) cycling, how it influences the dependence of this important biological process on environmental factors is unknown. Specifically, it is unclear how the relationships of net N mineralization (N_m) and soil moisture vary with soil properties and climates. In turn, how the relationships of N_m vs. soil properties and climates vary with soil moisture is also unknown. Therefore, soil samples from the 26 sites were collected within two climatic regions (i.e., arid and humid) across China. Then a four-week microcosmic incubation experiment was conducted at five soil moisture levels (20, 40, 60, 80, and 100% field water holding capacity (FWHC)) at 25 °C to measure the dynamics of N_m. The results showed that increasing soil moisture significantly increased N_m (+212%) and the N mineralization rate constant (k) (+0.26%), and that the effects of soil moisture were greater in humid soils (+250%) than arid soils (+178%). The slopes of the relationship between N_m vs. soil moisture increased with soil organic carbon (SOC) (+50.6%) and total N (TN) (+65.3%) concentrations, and decreased with pH (-43.0%) and clay content (-0.09%), especially in arid regions. Additionally, N_m was significantly correlated with soil properties and mean annual precipitation (MAP), and the slopes of most of these relationships increased with soil moisture in arid soils (+59.2-3805%), but decreased in humid soils (-1.96-140%). The results indicated that increasing soil moisture strengthened the dependence of N_m on soil properties and climates in arid soils, and that increasing soil pH and clay content reduced, but SOC and TN concentrations enhanced the dependence of N_m on soil moisture. Therefore, with changes in rainfall distribution patterns and an increase in extreme rainfall events, there is enormous potential for N_m in agricultural soils in arid regions, which is regulated by soil moisture and properties. On the contrary, in humid regions, the decoupling of the effects of soil moisture and soil properties on N mineralization could be due to microbial adaptation. Moreover, the coupled effects of soil environment and properties on N cycling in different climatic regions merit great consideration in experimental research as well as in biogeochemical model development and prediction.

Keywords: Climatic regions; Net N mineralization; Soil moisture; Soil pH; Soil texture; Substrates.

MeSH terms

Carbon / analysis
China
Climate*
Humidity
Nitrogen Cycle*
Nitrogen* / analysis
Soil* / chemistry
Water

Substances

Soil
Nitrogen
Water
Carbon