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Effect of extracellular-enzyme activities on solubilization rate of soil organic nitrogen

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Abstract

In a sandy soil containing 15N-labeled active (soluble and easily degradable) and non-labelled passive (recalcitrant) fractions of soil organic matter, the rate of net N mineralization (solubilization) was determined during a 55-day incubation at 25°C, 63% water-holding capacity and different levels of soil extracellular-enzyme activities. The active fraction of soil N was labelled by preincubation (at 5°C and 74% water-holding capacity for 6 months) of soil amended with 15N-labeled plant material. Increases in the activity of extracellular-enzymes in soil were induced by the addition of glucose and KH2PO4 at the beginning of the incubation. The results show that the contents of total soluble N (NO 3 −N+NH +4 −N + soluble organic N) were significantly higher in glucose-amended soil compared to the unamended soil. The increases in soluble N in soil amended with 1 and 2 mg glucose g-1 dry soil corresponded to a mean rate of net solubilization of 7.9±1.4 and 18.8±0.7 nmol N g-1 dry soil day-1, respectively. The mean rate of net N solubilization (3.6±1.0 nmol N g-1 dry soil day-1) in unamended soil was significantly lower than those of glucose amended soils. The content of 15N in total soluble N in soil amended with 2 mg glucose, for example, was diluted from 3.11±0.08 atom% before the incubation to 2.77±0.03 atom% after 55 days. This indicates that 89% of soluble-N accumulated in soil by the end of the incubation originated from the active fraction of soil N and the rest, estimated at 11%, originated from the passive fraction. The activities of soluble and total proteases as well as the rate of N solubilization in the soil increased with the application of glucose. The activity of these extracellular enzymes was highly correlated with the rates of net N solubilization. Thus, increases in extracellular-enzyme activities in glucose-amended soils had a priming effect on the solubilization of 15N-labeled active and non-labeled passive fractions of soil organic N. It seems that the activity of extracellular-enzymes expressed in terms of total and soluble protease activities could be a rate-limiting factor in the processes of soil organic N solubilization.

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References

  • Asmar F (1992) The role of extracellular enzymes and microbial biomass in the process of nitrogen mineralization in soil. PhD thesis, Royal Veterinary and Agricultural University, Copenhagen

  • Asmar F, Eiland F, Nielsen NE (1992) Interrelationship between extracellular-enzyme activity, ATP content, total counts of bacteria and CO2 evolution. Biol Fertil Soils 14:288–292

    Google Scholar 

  • Azam F, Stevenson FJ, Mulvaney RL, (1989) Chemical extraction of newly immobilized 15N and native soil N as influenced by substrate addition rate and soil treatments. Soil Biol Biochem 21:715–722

    Google Scholar 

  • Bonde TA, Schnurer J, Rosswall T (1988) Microbial biomass as fraction of potentially mineralizable nitrogen in soils from long-term field experiments. Soil Biol Biochem 20:281–286

    Google Scholar 

  • Bremner JM (1949) Studies on soil organic matter. Part 1. The chemical nature of soil organic nitrogen. J Agric Sci 39:183–193

    Google Scholar 

  • Carter MR, Rennie DA (1982) Changes in soil quality under zero tillage farming systems: Distribution of microbial biomass and mineralizable C and N potentials. Can J Soil Sci 62:587–597

    Google Scholar 

  • Clarholm M (1984) Heterotrophic, free living protozoa: Neglected microorganisms with an important task in regulating bacterial populations. In: Klug MJ, Reddy CA (eds) Current perspective in microbial ecology. Washington DC, American Society for Microbiology, pp 321–326

    Google Scholar 

  • Hadas A, Molina JAE, Feigenbaum S, Clapp CE (1987) Simulation of nitrogen-15 immobilization by the model of NCSOIL. Soil Sci Soc Am J 51:102–106

    Google Scholar 

  • Hendricks CW and Pascoe N (1988) Soil microbial biomass estimates using 2450 Mhz microwave irradiation. Pland and Soil 110:39–47

    Google Scholar 

  • Hunt HW (1977) A simulation model for decomposition in grasslands. Ecology 58:469–484

    Google Scholar 

  • Hauck RD, Bremner JM (1976) Use of tracers for soil and fertilizer research. Adv Agron 26:219–266

    Google Scholar 

  • Jansson SL (1971) Use of 15N in studies of soil nitrogen. In: McLaren AD, Skujins J (eds) Soil biochemistry, vol. 2. Dekker, New York, pp 129–166

    Google Scholar 

  • Jansson SL, Persson J (1968) Coordination of humus chemistry and soil organic matter biology by isotopic techniques. Isotopes and radiation in soil organic matter studies. Proceedings of a symposium, International Atomic Engergy Agency, Vienna, pp 109–123

  • Jansson SL, Persson J (1982) Mineralization and immobilization of soil nitrogen. In: Stevenson FG (ed) Nitrogen in agricultural soils. Agron Monogr 22, Am Soc Agron, Madison, Wis, pp 229–252

    Google Scholar 

  • Jenkinson DC (1966) Studies on the decomposition of plant material in soil. II. Partial sterilization of soil and the soil biomass. J Soil Sci 17:113–137

    Google Scholar 

  • Jenkinson DS, Ladd JN (1981) Microbial biomass in soil: Measurement and turn over. In: Paul EA, Ladd JN (eds) Soil biochemistry, vol 5. Elsevier, Amsterdam, pp 65–93

    Google Scholar 

  • Jenkinson DS, Fox RH, Rayner JH (1985) Interactions between fertilizer nitrogen and soil nitrogen — the so-called “priming” effect. J Soil Sci 36:425–444

    Google Scholar 

  • Jensen ES (1991) Evaluation of automated analysis of 15N and total N in plant material and soil. Plant and soil 123:83–92

    Google Scholar 

  • Ladd JN, Paul EA (1973) Changes in enzyme activity and distribution of acid soluble, amino acid nitrogen in soil during nitrogen immobilization and mineralization. Soil Biol Biochem 5:825–840

    Google Scholar 

  • Ladd JN, Parsons JW, Amato M (1977) Studies of nitrogen immobilization and mineralization in calcareous soils. II. Mineralization of immobilized nitrogen from soil fractions of different particle size and density. Soil Biol Biochem 9:319–325

    Google Scholar 

  • Ladd JN, Oades JM, Amato M (1981) Microbial biomass formed from 14C. 15N-labeled plant material decomposing in soils in the field. Soil Biol Biochem 13:119–126

    Google Scholar 

  • McGill WB, Shields JA, Paul EA (1975) Relation between carbon and nitrogen turnover in soil organic fractions of microbial origin. Soil Biol Biochem 7:57–63

    Google Scholar 

  • Molina JAE, Clapp CE, Shaffer MJ, Chichester FW, Larson WE (1983) NCSOIL, a model of nitrogen and carbon transformation in the soil: Description, calibration, and behaviour. Soil Sci Soc Am J 47:71–90

    Google Scholar 

  • Moorhead KK, Graetz DA, Reddy KR (1987) Decomposition of fresh and anaerobically digested plant biomass in soil. J Environ Qual 16:25–28

    Google Scholar 

  • Nannipieri P, Muccini L, Ciardi C (1983) Microbial biomass and enzyme activities: Production and persistence. Soil Biol Biochem 15:679–685

    Google Scholar 

  • Ocio JA, Martinez J, Brook PC (1991) Contribution of straw-derived N to total microbial biomass N following incorporation of cereal straw to soil. Soil Biol Biochem 23:655–659

    Google Scholar 

  • Olson RV (1980) Fate of tagged nitrogen fertilizer applied to irrigated corn. Soil Sci Soc Am J 44:514–517

    Google Scholar 

  • Payne JW (1980) Microorganisms and nitrogen sources. Wiley, New York, pp 381–411

    Google Scholar 

  • Phillip B, Molina JAE, Hadas A, Clapp CE (1990) Mineralization of amino acids and evidence of direct assimilation of organic nitrogen. Soil Sci Soc Am J 54:769–774

    Google Scholar 

  • Ruzicka J, Hansen EH (1981) Flow injection analysis. Wiley, New York

    Google Scholar 

  • Smart MM, Rada RG, Donnermeyer GN (1983) Determination of total nitrogen in sediments and plants using persulphate digestion. An evaluation and comparison with the Kjeldahl procedure. Water REs 17:1207–1211

    Google Scholar 

  • Warman PR, Bishop C (1987) Amino-N compounds found in soil organic matter hydrolysates of a loamy sand using an immobilized protease reactor column. Biol Fertil Soils 5:219–224

    Google Scholar 

  • Yoshinari T, Knowles R (1977) Acteylene inhibition of nitrous oxide reduction by denitrifying bacteria. Biochem Biophys Res Commun 69:705–710

    Google Scholar 

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Asmar, F., Eiland, F. & Nielsen, N.E. Effect of extracellular-enzyme activities on solubilization rate of soil organic nitrogen. Biol Fert Soils 17, 32–38 (1994). https://doi.org/10.1007/BF00418669

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