Nitrate content of surface waters results from complex mixing of multiple sources, whose signatures can be modified through N reactions occurring within the different compartments of the whole catchment. Despite this complexity, the determination of nitrate origin is the first and crucial step for water resource preservation. Here, for the first time, we combined at the catchment scale stable isotopic tracers (δN and δO of nitrate and δB) and fecal indicators to trace nitrate sources and pathways to the stream. We tested this approach on two rivers in an agricultural region of SW France. Boron isotopic ratios evidenced inflow from anthropogenic waters, microbiological markers revealed organic contaminations from both human and animal wastes. Nitrate δ and δO traced inputs from the surface leaching during high flow events and from the subsurface drainage in base flow regime. They also showed that denitrification occurred within the soils before reaching the rivers. Furthermore, this study highlighted the determinant role of the soil compartment in nitrate formation and recycling with important spatial heterogeneity and temporal variability.
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http://dx.doi.org/10.1038/srep41703 | DOI Listing |
Environ Res
January 2025
Department of Environment Sciences and Engineering, The Gillings School of Global Public Health, University of North Carolina at Chapel Hill, 166 Rosenau, Campus Box # 7431, NC 27599, Chapel Hill, North Carolina, USA. Electronic address:
Greywater, originating from kitchen sinks and toilets, constitutes 75-80 % of the domestic wastewater produced in homes and can be reclaimed for non-potable uses. This study synthesized novel sludge-derived aluminosilicates and alginate-polyethyleneimine (PEI) biochar composites. The aluminosilicates offer a sustainable approach to sludge management, while alginate-polyethyleneimine presents a green biochar modification approach.
View Article and Find Full Text PDFJ Environ Manage
January 2025
College of Resources and Environment, Academy of Agricultural Sciences, Southwest University, Chongqing, 400716, China; Interdisciplinary Research Center for Agriculture Green Development in Yangtze River Basin, Southwest University, Chongqing, 400716, China; Chongqing Key Laboratory of Efficient Utilization of Soil and Fertilizer Resources, Southwest University, Chongqing, 400716, China; Key Laboratory of Low-carbon Green Agriculture in Southwestern China, Ministry of Agriculture and Rural Affairs, Southwest University, Chongqing, 400716, China.
Nitrification inhibitors (NIs) are critical to reduce nitrogen (N) leaching losses. However, the efficacy of different NIs can be highly variable across soils and crop types, and a deeper understanding of the mechanistic basis of this efficiency variation, especially in purple soil under vegetable production, is lacking. To enrich this knowledge gap, the impact of different NIs amendment (3,4-dimethylpyrazole phosphate, DMPP; dicyandiamide, DCD; nitrapyrin, NP) on nitrification and the microbial mechanistic basis of controlling nitrate (NO-N) leaching of vegetable purple soil was explored in southwest China.
View Article and Find Full Text PDFGenes Genomics
January 2025
Department of Molecular Biosciences, Wenner-Gren Institute, Stockholm University, 106 91, Stockholm, Sweden.
Background: Cyanobacteria, particularly Synechocystis sp. PCC 6803, serve as model organisms for studying acclimation strategies that enable adaptation to various environmental stresses. Understanding the molecular mechanisms underlying these adaptations provides insight into how cells adjust gene expression in response to challenging conditions.
View Article and Find Full Text PDFSci Rep
January 2025
USDA-ARS Poultry Production and Product Safety Research Unit, Fayetteville, AR, 72701, USA.
Insect farming is expected to increase in coming years, thus generating high quantities of frass (insect excreta). Frass valorization hinges on basic agronomic research prior to industry upscaling. Here, we investigated soil physiochemical properties, SMAF (Soil Management Assessment Framework) soil health, CO efflux, and bermudagrass [Cynodon dactylon (L.
View Article and Find Full Text PDFNat Commun
January 2025
Cary Institute of Ecosystem Studies, Millbrook, NY, USA.
Previous estimates of deep soil inorganic nitrogen (N) reservoirs have been mainly limited to desert soils, however, recent evidence suggests that deep soil pools are far more ubiquitous across biomes and therefore may be important for global N budgets. Here, we used observations from 280 deep soil profiles (2-205 m) across a wide array of ecosystem and land cover types to seek insight into the full geospatial variation of deep soil nitrate. Using a random forest machine learning approach we estimate a total deep soil nitrate pool of 15.
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