Nitrogen root uptake

Measurements will be made of the form and levels of elements in soil, movement of elements to plant roots, uptake of elements by plant roots, and translocation to above-ground, and edible portions of plants. The elements to be studied include magnesium, calcium, potassium, zinc, phosphorous, nitrogen, iron, manganese, copper, and aluminum. 

J. Schniirer and T. Rosswall, Mineralization of nitrogen from N-labelled fungi, soil microbial biomass and roots,and its uptake by barley plants. Plant Soil 102 71 (1987). 

Tolley MD, DeLaune RD, Patrick WH. The effect of sediment redox potential and soil acidity on nitrogen uptake, anaerobic root respiration, and growth of rice (Oryza saliva). Plant Soil. 1986 93 323-331. 

Schachtman DP, Reid RJ, Ayling SM (1998) Phosphorus uptake by plants from soil to cell. Plant Physiol 116 447-453. doi http //www.plantphysiol.org Schindler DW (1974) Eutrophication and recovery in experimental lakes implications for lake management. Science 184 897-899. doi http //www.sciencemag.org/cgi/content/abstract/184/4139/897 Schindler DW, Hecky RE, Findlay DL, Stainton MP, Parker BR, Paterson MJ, Beaty KG, Lyng M, Kasian SEM (2008) Eutrophication of lakes cannot be controlled by reducing nitrogen input results of a 37-year whole-ecosystem experiment. Proc Natl Acad Sci USA 105 11254-11258. doi http //www.pnas.org/content/105/32/l 1254.abstract Scott JT, Condron LM (2003) Dynamics and availability of phosphorus in the rhizosphere of a temperate silvopastoral system. Biol Fert Soils 39 65-73 Shane MW, Lambers H (2005) Cluster roots a curiosity in context. Plant Soil 274 101-125. doi http //dx.doi.org/10.1007/s 11104-004-2725-7... 

Kirk GJD, Kronzucker HJ. 2000. Nitrogen uptake by rice roots. In Kirk GJD, Oik DC, eds. Carbon and Nitrogen Dynamics in Flooded Soils. Manila International Rice Research Institute, 147-162. 

Kirk GJD, Solivas JL. 1997. On the extent to which root properties and transport through the soil limit nitrogen uptake by lowland rice. European Journal of Soil Science 48 613-621. 

Vohnik M et al.. The inoculation with Oidiodendron mains and Phialocephala fortinii alters phosphorus and nitrogen uptake, foliar C N ratio and root biomass distribution in Rhododendron cv. Azurro, Symbiosis 40 87—96, 2005. 

Astragalus species are reported to tolerate very high concentrations of V which they utilise in nitrogen fixation (Cannon, 1963). Tolerance of high amounts of V in plants is due to immobilisation of the element as an insoluble product in the root, partial exclusion mechanisms also preventing uptake of the element from enriched soils (Peterson and Girling, 1981). 

The Michaelis-Menten equation is often employed in soil-water systems to describe kinetics of ion uptake by plant roots and microbial cells, as well as microbial degradation-transformation of organics (e.g., pesticides, industrial organics, nitrogen, sulfur, and natural organics) and oxidation or reduction of metals or metalloids. Derivation of the Michaelis-Menten equation(s) is demonstrated below. 

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