Globally, nitrate (NO) leaching from agroecosystems has been of major concern. There is evidence that NO 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 (N-enriched urea, 10 atom% excess) of 200 kg N ha yr was applied for maize. The effect of parent material on NO 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 NO leaching characteristics in surface layers. Environmental factors (precipitation and temperature) and fertilization together led to obvious seasonal characteristics, i.e. abundant NO leaching during both crop growth and fallow periods. In subsoil layers, NO leaching characteristics were completely different among three soils. The concentrations and δN of NO 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 NO leaching amount in BA soil was significantly lower than in the other two soils. These might be explained by different NO adsorption capacities caused by the differences in mineral composition and free iron and aluminium contents. These elucidated in subsoil layers, NO leaching characteristics highly depended on parent materials. Meanwhile, adsorption capacity was limited and cannot slow NO leaching in the long run. Our results suggest that seasonal variation of NO leaching in surface layers and temporary retardant effect from NO adsorption capacity in subsoil layers should receive much attention when calculating and predicting NO leaching in subtropical regions.
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http://dx.doi.org/10.1016/j.scitotenv.2024.170049 | DOI Listing |
J Environ Manage
January 2025
School of Environmental Science and Engineering, Tianjin University, Tianjin, 300072, China. Electronic address:
The continuously growing of municipal solid waste (MSW) has posed a threat to human-being. Pyrolysis is a promising technique for MSW disposal, as it can reduce its volume and produce valuable products as well. This study evaluated the potential of carbon residue (CR) derived from waste carton as soil amendment.
View Article and Find Full Text PDFJ Environ Manage
January 2025
School of Environmental Science and Engineering, Changzhou University, Changzhou, 213164, PR China.
Compared with zero-valent iron, iron sulfide has more diverse reactive species and higher reductivity, but it is still prone to be gradually deactivated due to various passivation factors. In this study, a novel reductive material (BMMW@OA) was prepared by ball milling of mackinawite (MW) as raw material and oxalic acid (OA) as modifier, so as to simultaneously improve its reductivity and stability by continuous releasing reductive species and maintaining freshness of the material surface. The BMMW@OA (w/w of MW/OA = 4/1) effectively removed Cr(Ⅵ) from water with wide pH adaptability.
View Article and Find Full Text PDFIntroduction: Rock weathering is a fundamental process that shapes Earth's topography, soil formation, and other surface processes. However, the mechanisms underlying the influence of fertilizer application on weathering remain poorly understood, especially with respect to bacterial intervention.
Methods: In this study, purple parent rocks from Shaximiao Group (Js) and Penglaizhen Group (Jp) were selected to investigate the effects of fertilizer application on the bacterial community and weathering characteristics of these rock by leaching experiment.
Sci Rep
January 2025
Shanxi Provincial Geological Prospecting Bureau, Taiyuan, 030001, China.
In China, a significant amount of coal fly ash is stored or used for landfill reclamation. The contaminants in coal fly ash (CFA) leachate can cause regional soil and groundwater contamination during long-term storage. This paper focuses on a coal gangue comprehensive utilisation power plant in Fenyang City, Shanxi Province, China, where the leaching characteristics of CFA were investigated by leaching tests.
View Article and Find Full Text PDFSci Rep
January 2025
College of Mechanical and Electrical Engineering, Mianyang Teachers' College, Mianyang, 621000, China.
Basaltic glass was prepared via the solid-state melt method, using Ce to simulate tetravalent actinides. The structure, thermal stability and leaching characteristics of basaltic glass with different contents of CeO were investigated. The XRD/SEM-EDX/Raman results showed that the simulated waste loading of CeO in basaltic glass reached ~ 18 wt%, and CeO crystals precipitated when the CeO content reached 20 wt%.
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