Nitrate leaching characteristics of red soils from different parent materials in subtropical China

Yue Dong; Jin-Ling Yang; Xiao-Rui Zhao; Shun-Hua Yang; Gan-Lin Zhang

doi:10.1016/j.scitotenv.2024.170049

Nitrate leaching characteristics of red soils from different parent materials in subtropical China

Sci Total Environ. 2024 Mar 10:915:170049. doi: 10.1016/j.scitotenv.2024.170049. Epub 2024 Jan 12.

Authors

Yue Dong¹, Jin-Ling Yang², Xiao-Rui Zhao³, Shun-Hua Yang³, Gan-Lin Zhang⁴

Affiliations

¹ Institute of Agricultural Resources and Environments, Jiangsu Academy of Agricultural Sciences, Nanjing 210014, China; State Key Laboratory of Soil and Sustainable Agriculture, Institute of Soil Science, Chinese Academy of Sciences, Nanjing 210008, China.
² State Key Laboratory of Soil and Sustainable Agriculture, Institute of Soil Science, Chinese Academy of Sciences, Nanjing 210008, China; University of Chinese Academy of Sciences, Beijing 100081, China.
³ State Key Laboratory of Soil and Sustainable Agriculture, Institute of Soil Science, Chinese Academy of Sciences, Nanjing 210008, China.
⁴ State Key Laboratory of Soil and Sustainable Agriculture, Institute of Soil Science, Chinese Academy of Sciences, Nanjing 210008, China; University of Chinese Academy of Sciences, Beijing 100081, China; Key Laboratory of Watershed Geographic Sciences, Nanjing Institute of Geography and Limnology, Chinese Academy of Sciences, Nanjing 210008, China. Electronic address: glzhang@issas.ac.cn.

PMID: 38218497
DOI: 10.1016/j.scitotenv.2024.170049

Abstract

Globally, nitrate (NO₃^-) leaching from agroecosystems has been of major concern. There is evidence that NO₃^- leaching exhibits intense seasonal variation in subtropical regions. However, influencing factors to the seasonal dynamics remain unclear. In this study, a two-year field lysimeters experiment was conducted with three red soils derived from different parent materials (Quaternary red clay (QR), red sandstone (RS), and basalt (BA)). An N fertilizer (¹⁵N-enriched urea, 10 atom% excess) of 200 kg N ha^-1 yr^-1 was applied for maize. The effect of parent material on NO₃^- leaching characteristics was examined in surface (0-20 cm) and subsoil (20-100 cm) layers. The results showed due to the weakening of abundant drainage, there was no significant effect of parent materials on NO₃^- leaching characteristics in surface layers. Environmental factors (precipitation and temperature) and fertilization together led to obvious seasonal characteristics, i.e. abundant NO₃^- leaching during both crop growth and fallow periods. In subsoil layers, NO₃^- leaching characteristics were completely different among three soils. The concentrations and δ¹⁵N of NO₃^- in QR and RS soils showed a continuous increase after first year's fertilization, while those in BA soil remained relatively stable after reaching peak levels around harvest in first year. Meanwhile, the NO₃^- leaching amount in BA soil was significantly lower than in the other two soils. These might be explained by different NO₃^- adsorption capacities caused by the differences in mineral composition and free iron and aluminium contents. These elucidated in subsoil layers, NO₃^- leaching characteristics highly depended on parent materials. Meanwhile, adsorption capacity was limited and cannot slow NO₃^- leaching in the long run. Our results suggest that seasonal variation of NO₃^- leaching in surface layers and temporary retardant effect from NO₃^- adsorption capacity in subsoil layers should receive much attention when calculating and predicting NO₃^- leaching in subtropical regions.

Keywords: (15)N tracing; Field lysimeter experiment; Nitrate leaching; Nitrogen translocation; Parent material; Red soil.