Nitrogen microbial biomass

P. C. Brookes, L. Landman, and D. S. Jenkin.son, Chloroform fumigation and the release of soil nitrogen a rapid extraction method to measure microbial biomass nitrogen in soil. Soil Biol. Biochem. 17331 (1985). 

Microbial biomass nitrogen Chloroform fumigation extraction Indicates biologically active fraction of soil nitrogen various methodologies controls nutrient cycling dependent upon organic inputs Rice et al. (1996)... 

Brookes, P. C., Landman, A., Pruden, G., and Jenkinson, D. S. (1985). Chloroform fumigation and the release of soil nitrogen A rapid direct extraction method to measure microbial biomass nitrogen in soil. Soil Biol. Biochem. 17, 837-842. Brookes, P. C., Powlson, D. S., and Jenkinson, D. S. (1982). Measurement of microbial biomass phosphorus in soil. Soil Biol. Biochem. 14, 319-321. 

Particulate organic nitrogen (detritus, soil, and water) Microbial biomass nitrogen (MBN) (detritus, soil, and water) Dissolved organic nitrogen (DON) (detritus, soil, and water) Inorganic forms of nitrogen... 

FIGURE 8.22 Relationship between microbial biomass carbon and microbial biomass nitrogen in organic soils (White and Reddy, 2001). 

Microbial communities assimilate and recycle nutrients within the biomass pool as needed. Soils that maintain high microbial biomass are not only capable of storing more nutrients but also greater cycling within the system. Microbial biomass nitrogen (MBN) was higher in detrital and surface soil layers of the impacted site than the reference site (Reddy et al., 1999 White and Reddy,... 

Note MBC = microbial biomass carbon MBN = microbial biomass nitrogen MBP phorus. MBP values are corrected for fumigation extraction efficiency. = microbial biomass phos- ... 

FIGURE 17.28 Relationship between potentially mineralizable nitrogen (PMN) and microbial biomass nitrogen of soil in four hydrologic units of the Everglades. (Wright, A., and Reddy, K. R., Unpublished Results, University of Florida.)... 

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). 

H.-O. Nohrstedt, K. Arnebrant, E. Baiith, and B. Soderstrom, Changes in carbon content, re.spiration rate, ATP content, and microbial biomass in nitrogen-fertilized pine forest soils in Sweden. Can. J. For. Res. 79 323 (1989). 

U. Schenk, R. Manderschied, J. Hugen, and H.-J. Weigel, Effects of CO, enrichment and intraspecific competition on biomass partitioning, nitrogen content and microbial biomass carbon in soil of perennial ryegrass and white clover, J. Exp. Bot. 46 987 (1995). 

D. A. Wardle, A comparative assessment of factors which influence microbial biomass carbon and nitrogen levels in soil, Biol. Rev. 67 321 (1992). 

Metals have been shown to negatively affect nitrogen transformation and urea hydrolysis. For example, Antil et al.69 discovered that the microbial biomass in a soil receiving sewer water or industrial wastewater decreased with increasing concentrations of cadmium and nickel. The rate of urea hydrolysis was 1.6 times greater in an uncontaminated soil than in a soil containing 0.026 mg Ni g 1. Ammonium concentrations increased for up to 14 days in a soil containing over... 

Antil, R.S., Gupta, A.P., and Narwal, R.P., Nitrogen transformation and microbial biomass content in soil contaminated with nickel and cadmium from industrial wastewater irrigation, Urban Water, 3 (4), 299-302, 2001. 

Lundquist EJ, Jackson LE, Scow KM, Hsu C (1999) Changes in microbial biomass and community composition, and soil carbon and nitrogen pools after incorporation of rye into three California agricultural soils. Soil Biol Biochem... 

Ros M, Pascuala JA, Garciaa C, Hemandeza MT, Insam H (2006) Hydrolase activities, microbial biomass and bacterial community in a soil after long-term amendment with different composts. Soil Biol Biochem 38 3443-3452 Rovira P, Vallejo VR (2002) Labile and recalcitrant pools of carbon and nitrogen in organic matter decomposing at different depths in soil an acid hydrolysis approach. Geoderma 107 109-141... 

Rice CW, Moorman TB, Beare M (1996) Role of Microbial Biomass Carbon and Nitrogen in Soil Quality. SSSA Special Pub 49 203-216... 

Soil microbes. Effects include reduced microbial biomass and/or species diversity, thus affecting microbial processes such as enzyme synthesis and activity, litter decomposition, associated with carbon and nitrogen mineralization, and soil respiration ... 

Figure 7. Relationship between net mineralization and immobilization of nitrogen as a function of substrate C N ratio and microbial assimilation efficiency (F) for three different biomass nitrogen levels equivalent to C N ratios of 4-8-12 (after Bashkin, 1987 Fenchel et al., 1998).

Oxygenic photosynthetic bacteria include the nitrogen fixer Trtchodesmtum and the cyanobacteria Synechococcus and Prochlorococcus. The latter represent a major fraction of the microbial biomass in the ocean and are probably the most abimdant primary producers in the ocean. They were not discovered until the late 1980s, probably because of their small size as they are members of the picoplankton. These cyanobacteria are photosynthetic. They use bacteriochlorophyll a and plastocyanin, a blue Cu-based pigment, for light harvesting. 

Dar, G.H. Impact of lead and sewage sludge on soil microbial biomass and carbon and nitrogen mineralization. B. Environ. Contam. Tox. 1997, 58, 234-240. 

Breland, T.A. and Eltun, R. 1999. Soil microbial biomass and mineralization of carbon and nitrogen in ecological, integrated and conventional forage and arable cropping systems. Biology and Fertility of Soils 30 193-201. 

Friedel, J.K., Gabel, D. and Stahr, K. 2001. Nitrogen pools and turnover in arable soils under different durations of organic farming II Source-and-sink function of the soil microbial biomass or competition with growing plants Journal of Plant Nutrition and Soil Science-Zeitschriftfur Pflanzenernahrung und Bodenkunde 164 421-429. 

Figure 1. A simplified watershed nitrogen cycle, with major pathways (arrows) and their effects on the watershed hydrogen budget (numbers in circles) shown. Circled numbers represent the number of hydrogen ions transferred to the soil solution or surface water ( +1) or from the soil solution or surface water (-l)for every molecule of N03 or NH4 + that follows a given pathway. For example, nitrification follows the pathway for NH4 + assimilation into microbial biomass ( + l) and is leached out as N03 ( + 1), for a total hydrogen ion production of +2 for every molecule of N03 produced.

Ajwa, H. A., C. J. Dell, and C. W. Rice. 1999. Changes in enzyme activities and microbial biomass of tallgrass prairie soil as related to burning and nitrogen fertilization. Soil Biology and Biochemistry 31 769-777. 

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