Journal Article

Long-term fate of nitrate fertilizer in agricultural soils

Ecosystèmes, biodiversité, évolution [Rennes] (ECOBIO) ; Université de Rennes (UR)-Institut Ecologie et Environnement (INEE) ; Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS)-Observatoire des Sciences de l'Univers de Rennes (OSUR) ; Université de Rennes (UR)-Institut national des sciences de l'Univers (INSU - CNRS)-Université de Rennes 2 (UR2)-Centre National de la Recherche Scientifique (CNRS)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE)-Institut national des sciences de l'Univers (INSU - CNRS)-Université de Rennes 2 (UR2)-Centre National de la Recherche Scientifique (CNRS)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE)-Centre National de la Recherche Scientifique (CNRS), Biogéochimie et écologie des milieux continentaux (Bioemco) ; École normale supérieure - Paris (ENS-PSL) ; Université Paris sciences et lettres (PSL)-Université Paris sci

2013

Overview

Increasing diffuse nitrate loading of surface waters and groundwater has emerged as a major problem in many agricultural areas of the world, resulting in contamination of drinking water resources in aquifers as well as eutrophication of freshwaters and coastal marine ecosystems. Although empirical correlations between application rates of N fertilizers to agricultural soils and nitrate contamination of adjacent hydrological systems have been demonstrated, the transit times of fertilizer N in the pedosphere-hydrosphere system are poorly understood. We investigated the fate of isotopically labeled nitrogen fertilizers in a three-decade-long in situ tracer experiment that quantified not only fertilizer N uptake by plants and retention in soils, but also determined to which extent and over which time periods fertilizer N stored in soil organic matter is rereleased for either uptake in crops or export into the hydrosphere.We found that 61-65% of the applied fertilizers N were taken up by plants,whereas 12-15% of the labeled fertilizer Nwere still residing in the soil organic matter more than a quarter century after tracer application. Between 8-12% of the applied fertilizer had leaked toward the hydrosphere during the 30-y observation period. We predict that additional exports of 15N-labeled nitrate from the tracer application in 1982 toward the hydrosphere will continue for at least another five decades. Therefore, attempts to reduce agricultural nitrate contamination of aquatic systems must consider the long-term legacy of past applications of synthetic fertilizers in agricultural systems and the nitrogen retention capacity of agricultural soils.

• Publisher: National Academy of Sciences,HAL CCSD,NATIONAL ACADEMY OF SCIENCES,National Acad Sciences
• Subject: Agricultural land / agricultural soils / Agrochemicals / Agronomy. Soil science and plant productions / Animal, plant and microbial ecology / Applied ecology / Applied sciences / Aquatic environment / Aquifers / Biological and medical sciences / Biological Sciences / Coastal ecosystems / Colorimetry / Contamination / crops / Drinking water / Environmental Monitoring - statistics & numerical data / Environmental Pollution - analysis / Environmental Sciences / Eutrophication / Exact sciences and technology / Farming systems / fertilizer rates / Fertilizers / Fertilizers - analysis / France / Fundamental and applied biological sciences. Psychology / General agronomy. Plant production / Grassland soils / Groundwater / Groundwater - chemistry / Hydrosphere / isotope labeling / Marine ecosystems / Mass Spectrometry / nitrate fertilizers / Nitrates / Nitrates - analysis / Nitrates - pharmacokinetics / Nitrogen / Nitrogen Isotopes - analysis / Nitrogen, phosphorus, potassium fertilizations / Organic fertilizers / Organic matter / Organic soils / Oxygen Isotopes - analysis / Pedosphere / Physical Sciences / Plants - metabolism / Pollution / Retention / Retention capacity / Soil - chemistry / Soil and water pollution / Soil biochemistry / Soil organic matter / Soil pollution / Soil science / Soil water / Soil-plant relationships. Soil fertility. Fertilization. Amendments / Soils / Surface water / Time Factors / Water resources / Water treatment and pollution
• ISBN: 0003265508000