Topic
Phosphorus
About: Phosphorus is a research topic. Over the lifetime, 53120 publications have been published within this topic receiving 939731 citations. The topic is also known as: element 15 & P.
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929 citations
TL;DR: Effects of nitrogen and phosphorus concentrations on growth, nutrient uptake, and lipid accumulation of a freshwater microalga Scenedesmus sp.
922 citations
TL;DR: In the deltaic plain of the Ganges-Meghna-Brahmaputra Rivers, arsenic concentrations in groundwater commonly exceed regulatory limits because FeOOH is microbially reduced and releases its sorbed load of arsenic to groundwater as mentioned in this paper.
Abstract: In the deltaic plain of the Ganges-Meghna-Brahmaputra Rivers, arsenic concentrations in groundwater commonly exceed regulatory limits (.50 m gL 21 ) because FeOOH is microbially reduced and releases its sorbed load of arsenic to groundwater. Neither pyrite oxidation nor competitive exchange with fertilizer phosphate contribute to arsenic pollution. The most intense reduction and so severest pollution is driven by microbial degradation of buried deposits of peat. Concentrations of ammonium up to 23 mg L 21 come from microbial fermentation of buried peat and organic waste in latrines. Concentrations of phosphorus of up to 5 mg L 21 come from the release of sorbed phosphorus when FeOOH is reductively dissolved and from degradation of peat and organic waste from latrines. Calcium and barium in groundwater come from dissolution of detrital (and possibly pedogenic) carbonate, while magnesium is supplied by both carbonate dissolution and weathering of mica. The 87 Sr/ 86 Sr values of dissolved strontium define a two-component mixing trend between monsoonal rainfall (0.711 6 0.001) and detrital carbonate (,0.735).
893 citations
TL;DR: The results support the hypothesis that aeolian mineral dust deposition promotes nitrogen fixation in the eastern tropical North Atlantic and show that community primary productivity was nitrogen-limited, and that nitrogen fixation was co-limited by iron and phosphorus.
Abstract: The role of iron in enhancing phytoplankton productivity in high nutrient, low chlorophyll oceanic regions was demonstrated first through iron-addition bioassay experiments1 and subsequently confirmed by large-scale iron fertilization experiments2. Iron supply has been hypothesized to limit nitrogen fixation and hence oceanic primary productivity on geological timescales3, providing an alternative to phosphorus as the ultimate limiting nutrient4. Oceanographic observations have been interpreted both to confirm and refute this hypothesis5, 6, but direct experimental evidence is lacking7. We conducted experiments to test this hypothesis during the Meteor 55 cruise to the tropical North Atlantic. This region is rich in diazotrophs8 and strongly impacted by Saharan dust input9. Here we show that community primary productivity was nitrogen-limited, and that nitrogen fixation was co-limited by iron and phosphorus. Saharan dust addition stimulated nitrogen fixation, presumably by supplying both iron and phosphorus10, 11. Our results support the hypothesis that aeolian mineral dust deposition promotes nitrogen fixation in the eastern tropical North Atlantic.
886 citations