Nitrogen (N) plays an important role in agricultural production. This study was designed to evaluate the presence of cultivable N cycle-associated microorganisms (nitrogen-fixing bacteria—NFB, proteolytic bacteria—PR, ammonifiers—AMO, ammonium-oxidizing bacteria—AOB, nitrite-oxidizing bacteria—NOB, and denitrifiers—DEN), and their relationship with physical-chemical and agronomic soil descriptors, in Solanum phureja rhizospheric soil samples, from traditional and organic crop management farms. A cluster analysis with the physical and chemical properties of soil, allowed to identify the organic matter content as an important factor that determines the outcome of that grouping. Significant differences ( ) between farms were found in the abundance of this groups, but correlation analysis showed that proteolytic and nitrogen fixing bacteria were the main nitrogen associated functional groups affected by soils' physical-chemical characteristics. The amount of ammonia available is affected by the agricultural management strategy, which consequently affects the NFB abundance. Finally the results showed that PR, protease activity and soil properties related with organic matter transformation has a positive relationship with productivity, which given the high organic matter content of the Andean soils being studied, we conclude that nitrogen mineralization process has an important role in the nitrogen cycle and its bioavailability in this ecosystem. 1. Introduction Potato is the world’s fourth most popular food crop and one of the most important agricultural products for Colombia; it occupies the ninth place in area sown regarding transitory crops and sixth place in production value [1]. Solanum phureja is a native potato representing around 10% of potato crops produced in Colombia (having around 25,000 hectares planted and 150,000 tons produced per year), making Colombia the highest producer of such native potato amongst Andean countries [2–4]. The regions where potato crops are planted in Colombia are characterized by having a cold to very cold climate, due to their high altitude in the Andean mountains (2,000 meters above sea level (masl) to 3,500 masl), where fragile ecosystems such as Paramo are located. Such climatic conditions define important soil characteristics since they limit organic matter’s mineralization speed, this being one of the reasons for which the aforementioned soils are characterized by presenting high organic matter content (usually above 10%). The volcanic ash from andisols is considered to be the material of origin partially or
References
[1]
C. Espinal, H. Martínez, N. Pinzón, and C. Barrios, “La cadena de la papa en colombia una mirada global de su estructura y dinamica 1991–2005,” Documento de Trabajo no. 54, Ministerio de Agricultura y Desarrollo Rural Observatorio Agrocadenas, Bogotá, Colombia, 2005.
[2]
C. E. ？ústez, “La papa criolla (Solanum phureja): un cultivo para destacar en Colombia,” Boletín de la Papa, vol. 3, no. 25, 2001.
[3]
C. Diazgranados and A. Chaparro-Giraldo, “Desarrollo de un sistema de regeneración en papa criolla Solanum phureja Juz. et. Buk. Var. yema de huevo clon 1,” Agronomía Colombiana, vol. 25, pp. 7–15, 2007.
[4]
P. D. Porras, “La papa en Colombia: desarrollo de una Cadena agroalimentaria estratégica,” Revista Papa, vol. 20, pp. 5–29, 1999.
[5]
R. L. Parfitt, “Allophane and imogolite: role in soil biogeochemical processes,” Clay Minerals, vol. 44, no. 1, pp. 135–155, 2009.
[6]
H. Castro, “Balance y prospectiva de la investigación en el campo de la fertilización para el sistema de producción de papa en Colombia,” in Proceedings of the 1st Taller Nacional sobre suelos, fisiología y nutrición vegetal en el cultivo de la papa, Bogotá, Colombia, February 2005.
[7]
H. J. Villamil, “Fisiología de la nutrición en papa,” in Proceedings of the 1st Taller Nacional Sobre Suelos, Fisiología y Nutrición Vegetal en el Cultivo de la Papa, Bogotá, Colombia, February 2005.
[8]
H. Ruiz, “Inventario de la oferta tecnológica para la fertilización en el cultivo de la papa en Colombia,” in Proceedings of the 1st Taller Nacional Sobre Suelos, Fisiología y Nutrición Vegetal en el Cultivo de la Papa, Bogotá, Colombia, February 2005.
[9]
H. Villareal, P. Porras, A. Santa, J. Logoeyte, and D. Mu？oz, “Costos de producción de papa en las principales zonas productoras de Colombia,” 2007, http://www.fedepapa.org.co/files/estadistica/estudio.pdf.
[10]
C. M. Giletto, H. E. Echeverria, and V. Sadras, “Nitrogen fertilization of potato in the southern pampas,” Ciencia del Suelo, vol. 21, no. 2, pp. 44–51, 2003.
[11]
J. A. Saluzzo, H. E. Echeverría, F. H. Andrade, and M. Huarte, “Nitrogen nutrition of potato cultivars differing in maturity,” Journal of Agronomy and Crop Science, vol. 183, no. 3, pp. 157–165, 1999.
[12]
G. E. Kleinkopf, D. T. Westermann, and R. B. Dwelle, “Dry matter production and nitrogen utilization by six potato cultivars,” Agronomy Journal, vol. 73, pp. 799–802, 1981.
[13]
R. V. Rourke, “Soil solution levels of nitrate nitrogen in a potato-buckwheat rotation,” American Potato Journal, vol. 62, no. 1, pp. 1–8, 1985.
[14]
G. A. Porter and J. A. Sisson, “Petiole nitrate content of Maine-grown Russet Burbank and Shepody potatoes in response to varying nitrogen rate,” American Potato Journal, vol. 68, no. 8, pp. 493–505, 1991.
[15]
J. N. Galloway, A. R. Townsend, J. W. Erisman et al., “Transformation of the nitrogen cycle: recent trends, questions, and potential solutions,” Science, vol. 320, no. 5878, pp. 889–892, 2008.
[16]
V. Smil, “Global population and the nitrogen cycle,” Scientific American, vol. 277, pp. 76–81, 1997.
[17]
P. M. Vitousek, J. D. Aber, R. W. Howarth et al., “Human alteration of the global nitrogen cycle: sources and consequences,” Ecological Applications, vol. 7, no. 3, pp. 737–750, 1997.
[18]
T. Rosswall, “The internal nitrogen cycle between microorganisms, vegetation and soil,” Ecological Bulletins, pp. 157–167, 1976.
[19]
L. E. Jackson, M. Burger, and T. R. Cavagnaro, “Roots, nitrogen transformations, and ecosystem services,” Annual Review of Plant Biology, vol. 59, pp. 341–363, 2008.
[20]
R. J. Rennie, “A single medium for the isolation of acetylene-reducing (dinitrogen-fixing) bacteria from soils,” Canadian Journal of Microbiology, vol. 27, no. 1, pp. 8–14, 1981.
[21]
J. Pochon and P. Tardieux, Techniques d'Analyse en Microbiologie du Sol, éditions de la Tourelle, Saint-Mandé, France, 1962.
[22]
H. J. Bach and J. C. Munch, “Identification of bacterial sources of soil peptidases,” Biology and Fertility of Soils, vol. 31, no. 3-4, pp. 219–224, 2000.
[23]
E. Amora-Lazcano, M. M. Vázquez, and R. Azcón, “Response of nitrogen-transforming microorganisms to arbuscular mycorrhizal fungi,” Biology and Fertility of Soils, vol. 27, no. 1, pp. 65–70, 1998.
[24]
M. Alexander and F. E. Clark, “Nitrifying bacteria,” in Methods of Soil Analysis, M. Alexander, F. E. Clark, and C. A. Black, Eds., part 2, pp. 1477–1483, American Society of Agronomy, Madison, Wis, USA, 1965.
[25]
Y. Horiba, S. T. Khan, and A. Hiraishi, “Characterization of the microbial community and culturable denitrifying bacteria in a solid-phase denitrification process using poly ( -caprolactone) as the carbon and energy source,” Microbes and Environments, vol. 20, pp. 25–33, 2005.
[26]
M. H. McCrady, “Tables for rapid interpretation of fermentation tube results,” Public Health Journal Toronto, vol. 9, pp. 201–220, 1918.
[27]
J. N. Ladd and J. H. A. Butler, “Short-term assays of soil proteolytic enzyme activities using proteins and dipeptide derivatives as substrates,” Soil Biology and Biochemistry, vol. 4, no. 1, pp. 19–30, 1972.
[28]
R. W. F. Hardy, R. D. Holsten, E. K. Jackson, and R. C. Burns, “The acetylene-ethylene assay for N2 fixation: laboratory and field evaluation,” Plant Physiology, vol. 43, pp. 1185–1207, 1968.
[29]
W. H. Kruskal and W. A. Wallis, “Use of ranks in one-criterion variance analysis,” Journal of the American statistical Association, vol. 47, pp. 583–621, 1952.
[30]
StataCorp, Stata Statistical Software: Release 9, StataCorp LP, College Station, Tex, USA, 2005.
[31]
R Development Core Team, R: A Language and Environment for Statistical Computing, R Foundation for Statistical Computing, Vienna, Austria, 2008, ISBN 3-900051-07-0.
[32]
P. M？der, A. Flie？bach, D. Dubois, L. Gunst, P. Fried, and U. Niggli, “Soil fertility and biodiversity in organic farming,” Science, vol. 296, no. 5573, pp. 1694–1697, 2002.
[33]
L. R. Bulluck, M. Brosius, G. K. Evanylo, and J. B. Ristaino, “Organic and synthetic fertility amendments influence soil microbial, physical and chemical properties on organic and conventional farms,” Applied Soil Ecology, vol. 19, no. 2, pp. 147–160, 2002.
[34]
A. S. F. Araújo, V. B. Santos, and R. T. R. Monteiro, “Responses of soil microbial biomass and activity for practices of organic and conventional farming systems in Piauí state, Brazil,” European Journal of Soil Biology, vol. 44, no. 2, pp. 225–230, 2008.
[35]
D. D. Myrold, “Transformations of nitrogen,” in Principles and Applications of Soil Microbiology, D. M. Sylvia, J. J. Fuhrmann, P. G. Hartel, and D. A. Zuberer, Eds., pp. 333–372, Prentice Hall, Englewood Cliffs, NJ, USA, 2005.
[36]
J. Howe and M. Wagner, “The effect of papermill wastewater and organic amendments on sodium accumulation by potted cottonwoods,” Environmental Pollution, vol. 92, no. 2, pp. 113–118, 1996.
[37]
G. P. Sparling, T. Graham Shepherd, and H. A. Kettles, “Changes in soil organic C, microbial C and aggregate stability under continuous maize and cereal cropping, and after restoration to pasture in soils from the Manawatu region, New Zealand,” Soil and Tillage Research, vol. 24, no. 3, pp. 225–241, 1992.
[38]
F. Houwaard, “Influence of ammonium and nitrate nitrogen on nitrogenase activity of pea plants as affected by light intensity and sugar addition,” Plant and Soil, vol. 54, no. 2, pp. 271–282, 1980.
[39]
R. Knowles and D. Denike, “Effect of ammonium-, nitrite- and nitrate nitrogen on anaerobic nitrogenase activity in soil,” Soil Biology and Biochemistry, vol. 6, no. 6, pp. 353–358, 1974.
[40]
V. Rajaramamohan-Rao, “Nitrogen fixation as influenced by moisture content, ammonium sulphate and organic sources in a paddy soil,” Soil Biology and Biochemistry, vol. 8, no. 5, pp. 445–448, 1976.
[41]
D. Kleiner, “Ammonium uptake and metabolism by nitrogen fixing bacteria,” Archives of Microbiology, vol. 111, no. 1-2, pp. 85–91, 1976.
[42]
A. Hartmann and R. H. Burris, “Regulation of nitrogenase activity by oxygen in Azospirillum brasilense and Azospirillum lipoferum,” Journal of Bacteriology, vol. 169, no. 3, pp. 944–948, 1987.
[43]
R. L. Smith, C. Van Baalen, and F. R. Tabita, “Alteration of the Fe protein of nitrogenase by oxygen in the Cyanobacterium anabaena sp. strain CA,” Journal of Bacteriology, vol. 169, no. 6, pp. 2537–2542, 1987.
[44]
D. A. Zuberer, “Biological dinitrogen fixation: introduction and nonsymbiotic,” in Principles and Applications of Soil Microbiology, D. M. Sylvia, J. J. Fuhrmann, P. G. Hartel, and D. A. Zuberer, Eds., pp. 373–404, Prentice Hall, Englewood Cliffs, NJ, USA, 2005.
[45]
S. J. Ferguson, “Nitrogen cycle enzymology,” Current Opinion in Chemical Biology, vol. 2, no. 2, pp. 182–193, 1998.
[46]
K. C. Marshall, “Clay mineralogy in relation to survival of soil bacteria,” Annual Review of Phytopathology, vol. 13, pp. 357–373, 1975.
[47]
H. Arslan, G. Güleryüz, and S. Kirmizi, “Nitrogen mineralisation in the soil of indigenous oak and pine plantation forests in a Mediterranean environment,” European Journal of Soil Biology, vol. 46, no. 1, pp. 11–17, 2010.
[48]
F. Gastal and G. Lemaire, “N uptake and distribution in crops: An agronomical and ecophysiological perspective,” Journal of Experimental Botany, vol. 53, no. 370, pp. 789–799, 2002.
[49]
L. B？hme and F. B？hme, “Soil microbiological and biochemical properties affected by plant growth and different long-term fertilisation,” European Journal of Soil Biology, vol. 42, no. 1, pp. 1–12, 2006.
[50]
J. P. Schimel and J. Bennett, “Nitrogen mineralization: challenges of a changing paradigm,” Ecology, vol. 85, no. 3, pp. 591–602, 2004.
[51]
M. M. Fuka, M. Engel, A. Gattinger et al., “Factors influencing variability of proteolytic genes and activities in arable soils,” Soil Biology and Biochemistry, vol. 40, no. 7, pp. 1646–1653, 2008.
[52]
T. Kunito, K. Saeki, S. Goto, H. Hayashi, H. Oyaizu, and S. Matsumoto, “Copper and zinc fractions affecting microorganisms in long-term sludge-amended soils,” Bioresource Technology, vol. 79, no. 2, pp. 135–146, 2001.
[53]
S. Saha, K. A. Gopinath, B. L. Mina, and H. S. Gupta, “Influence of continuous application of inorganic nutrients to a Maize-Wheat rotation on soil enzyme activity and grain quality in a rainfed Indian soil,” European Journal of Soil Biology, vol. 44, no. 5-6, pp. 521–531, 2008.
