Accumulation of toxic elements Fertilizer

1 accumulation of toxic elements

1.1 cadmium
1.2 fluoride
1.3 radioactive elements
1.4 other metals

accumulation of toxic elements
cadmium

the concentration of cadmium in phosphorus-containing fertilizers varies considerably , can problematic. example, mono-ammonium phosphate fertilizer may have cadmium content of low 0.14 mg/kg or high 50.9 mg/kg. because phosphate rock used in manufacture can contain as 188 mg/kg cadmium (examples deposits on nauru , christmas islands). continuous use of high-cadmium fertilizer can contaminate soil (as shown in new zealand) , plants. limits cadmium content of phosphate fertilizers has been considered european commission. producers of phosphorus-containing fertilizers select phosphate rock based on cadmium content.

fluoride

phosphate rocks contain high levels of fluoride. consequently, widespread use of phosphate fertilizers has increased soil fluoride concentrations. has been found food contamination fertilizer of little concern plants accumulate little fluoride soil; of greater concern possibility of fluoride toxicity livestock ingest contaminated soils. of possible concern effects of fluoride on soil microorganisms.

radioactive elements

the radioactive content of fertilizers varies considerably , depends both on concentrations in parent mineral , on fertilizer production process. uranium-238 concentrations can range 7 100 pci/g in phosphate rock , 1 67 pci/g in phosphate fertilizers. high annual rates of phosphorus fertilizer used, can result in uranium-238 concentrations in soils , drainage waters several times greater present. however, impact of these increases on risk human health radinuclide contamination of foods small (less 0.05 msv/y).

other metals

steel industry wastes, recycled fertilizers high levels of zinc (essential plant growth), wastes can include following toxic metals: lead arsenic, cadmium, chromium, , nickel. common toxic elements in type of fertilizer mercury, lead, , arsenic. these potentially harmful impurities can removed; however, increases cost. highly pure fertilizers available , perhaps best known highly water-soluble fertilizers containing blue dyes used around households, such miracle-gro. these highly water-soluble fertilizers used in plant nursery business , available in larger packages @ less cost retail quantities. there inexpensive retail granular garden fertilizers made high purity ingredients.