Five-year vegetation conversion from pasture to C3 and C4 plants affects dynamics of SOC and TN and their natural stable C and N isotopes via mediating C input and N leaching

Yuka Hosogoe; Toan Nguyen-Sy; Shuirong Tang; Putu Oki Bimantara; Yuka Sekikawa; Valensi Kautsar; Samuel Munyaka Kimani; Xingkai Xu; Keitaro Tawaraya; Weiguo Cheng

doi:10.1016/j.scitotenv.2023.169481

Five-year vegetation conversion from pasture to C₃ and C₄ plants affects dynamics of SOC and TN and their natural stable C and N isotopes via mediating C input and N leaching

Sci Total Environ. 2024 Feb 20:912:169481. doi: 10.1016/j.scitotenv.2023.169481. Epub 2023 Dec 21.

Authors

Affiliations

¹ Graduate School of Agricultural Sciences, Yamagata University, Tsuruoka 997-8555, Japan.
² The United Graduate School of Agricultural Sciences, Iwate University, Morioka 020-8550, Japan; Faculty of Chemical Technology-Environment, University of Technology and Education-The University of Da Nang, Da Nang 550000, Viet Nam.
³ Faculty of Agriculture, Yamagata University, Tsuruoka 997-8555, Japan; School of Tropical Agricultural and Forestry (School of Agricultural and Rural Affairs, School of Rural Revitalization), Hainan University, Haikou 570228, China. Electronic address: tangshuirong@163.com.
⁴ Faculty of Agriculture, Yamagata University, Tsuruoka 997-8555, Japan.
⁵ The United Graduate School of Agricultural Sciences, Iwate University, Morioka 020-8550, Japan.
⁶ State Key Laboratory of Atmospheric Boundary Layer Physics and Atmospheric Chemistry, Institute of Atmospheric Physics, Chinese Academy of Sciences, Beijing 100029, China; College of Earth and Planetary Sciences, University of Chinese Academy of Sciences, Beijing 100049, China.
⁷ Graduate School of Agricultural Sciences, Yamagata University, Tsuruoka 997-8555, Japan; The United Graduate School of Agricultural Sciences, Iwate University, Morioka 020-8550, Japan; Faculty of Agriculture, Yamagata University, Tsuruoka 997-8555, Japan.

PMID: 38142001
DOI: 10.1016/j.scitotenv.2023.169481

Abstract

Understanding the effects of land-use change on stock and composition of soil organic carbon (SOC) and nitrogen (N) is pivotal for sustainable agriculture and climate change adaption. However, previous studies have often overlooked the specific vegetation type in land-use changes. Therefore, a five-year lysimeter block experiment was conducted, involving non-vegetation, eulalia (C₄ plant), and clover (C₃ plant) to investigate the impacts of vegetation conversion from pasture on SOC and N dynamics and their natural stable isotopes. Non-vegetation caused 26.21 % and 25.88 % decreases in SOC and total N (TN) contents. Five-year eulalia and clover cultivation maintained stable SOC content, with clover exhibiting higher soil TN content. Eulalia-derived soil C was 1.64-7.58 g C kg^-1 and SOC loss in eulalia treatment was 1.86-7.90 g C kg^-1. Soil δ¹³C in eulalia increased at a rate of 0.90 ‰ year^-1, significantly surpassing clover and non-vegetation treatments. Conversely, soil δ¹⁵N decreased over time, showing insignificant difference among all treatments. Eulalia exhibited significantly higher dry weight and δ¹³C but lower TN content compared with clover. However, no significant differences were observed in total C and δ¹⁵N between the two vegetation treatments. Non-vegetation exhibited higher dissolved organic C concentration than two vegetation treatments in 2017, decreasing over time. Dissolved TN and nitrate concentrations in leachate followed the order clover> non-vegetation> eulalia, with nitrate being the predominant form of N leaching from leachate. Our findings reveal that vegetation conversion affects soil C and N contents, and alters their natural isotopes as well as the leaching of labile soluble nutrients. Notably, non-vegetation consistently reduced SOC and TN contents, whereas eulalia cultivation maintained SOC content, improved C/N ratio and δ¹³C, and reduced N leaching compared with clover cultivation. These results highlight the potential of eulalia as a candidate plant for enhancing C sequestration and reducing N leaching in cold regions of Japan.

Keywords: Climate change; Lysimeter experiment; Soil organic matter; Vegetation conversion; δ(13)C; δ(15)N.