Phosphorus speciation and C:N:P stoichiometry of functional organic matter fractions in temperate forest soils
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Background and aims
Phosphorus (P) availability is crucial for forest ecosystem productivity and soil organic matter (SOM) is an important source for P. This study was conducted to reveal carbon (C), nitrogen (N) and P distributions in functional SOM fractions. We hypothesised that (1) most of the organic P (Porg) is part of the particulate SOM, (2) particulate SOM stores increasing share of P with decreasing soil P content and (3) the C:Porg ratio of mineral-associated SOM is smaller than that of particulate SOM.
We analysed soil samples from five temperate forest sites (Fagus sylvatica) under different geological parent material with a wide range of total P concentrations. Density fractionation was used to separate free light fraction (fLF), particulate SOM occluded within soil aggregates (occluded light fraction; oLF), and mineral associated SOM (heavy fraction; HF). We determined the mass balance of P in these fractions, in addition to the C and N concentrations. Additionally, the P speciation of the topsoil was analysed by X-ray absorption near edge structure (XANES) spectroscopy at the P K-edge.
The fLF contained 18–54% and the oLF 1–15% of total P (Ptot). High percentage of P in these light fractions was associated to soil minerals. Phosphorous in particulate SOM within aggregates tend to increase with decreasing soil P. The HF containing mineral-associated OM, comprised 38–71% of Ptot and their C:Porg ratios were consistently lower than those of the fLF irrespective of the P status of the soil.
We show that all three functional SOM fractions contain variable amount of both organic and inorganic P species. The free light fraction shows no response to changing P stocks of soils.. Despite physically protected particulate SOM, oLF, becomes increasingly relevant as P cache in soils with declining P status.
KeywordsEcosystem nutrition Density fractions Soil organic matter C:N:P ratio Phosphorus P K-edge XANES
Dissolved organic matter
Free light fraction
Inductively coupled plasma optical emission spectrometry
Linear combination fitting
Occluded light fraction
Soil organic matter
X-ray absorption near edge structure
We want to thank the German Research Foundation DFG for funding this study as part of the priority program SPP 1685 (Projects: LA 1398/12-1, MI 1377/7-1and PR 534/6-1) and Sigrid Hiesch for the carefully realisation of the HNO3/HClO4/HF digestion.
- Ad-hoc-AG Boden (2005) Bodenkundliche Kartieranleitung (KA 5), Hannover, 5th edn. E. Schweizerbart'sche Verlagsbuchhandlung, StuttgartGoogle Scholar
- Amelung W, Zech W (1999) Minimisation of organic matter disruption during particle-size fractionation of grassland epipedons. Geoderma 92:73–85. http://dx.doi.org/10.1016/S0016-7061(99)00023-3
- Attiwil PM, Adams MA (1993) Nutrient cycling in forests. New Phytol 124:561–582. https://doi.org/10.1111/j.1469-8137.1993.tb03847.x CrossRefGoogle Scholar
- Condron LM, Turner BL, Cade-Menun BJ (2005) Chemistry and dynamics of soil organic phosphorus. In: Sims JT, Sharpley AN (eds) Phosphorus: agriculture and the environment, agronomy monograph 46. ASA, CSSA, and SSSA, Madison, p 87–121. https://doi.org/10.2134/agronmonogr46.c4
- Golchin A, J. M. Oades, J. O. Skjemstad, P. Clarke (1994) Study of free and occluded particulate organic matter in soils by solid state C CP/MAS NMR spectroscopy and scanning electron microscopy. Aust J Soil Res 32:285–309.Google Scholar
- Gunina A, Kuzyakov Y (2014) Pathways of litter C by formation of aggregates and SOM density fractions: implications from 13C natural abundance. Soil Biol Biochem 71:95–104. http://dx.doi.org/10.1016/j.soilbio.2014.01.011
- Hedley MJ, Stewart JWB, Chauhan BS (1982) Changes in inorganic and organic soil phosphorus fractions induced by cultivation practices and by laboratory Incubations1. Soil Sci Soc Am J 46:970–976. https://doi.org/10.2136/sssaj1982.03615995004600050017x CrossRefGoogle Scholar
- Jastrow JD, Miller RM (1997) Soil aggregate stabilization and carbon sequestration: feedbacks through organomineral associations. In: Lal R, Kimble JM, Follett RF, Stewart BA (eds) Soil processes and the carbon cycle. CRC Press, Boca Raton, p 207–223Google Scholar
- Kögel-Knabner I, Guggenberger G, Kleber M, Kandeler E, Kalbitz K, Scheu S, Eusterhues K, Leinweber P (2008) Organo-mineral associations in temperate soils: integrating biology, mineralogy, and organic matter chemistry. J Plant Nutr Soil Sci 171:61–82. https://doi.org/10.1002/jpln.200700048 CrossRefGoogle Scholar
- Lang F, Bauhus J, Frossard E, George E, Kaiser K, Kaupenjohann M, Krüger J, Matzner E, Polle A, Prietzel J, Rennenberg H, Wellbrock N (2016) Phosphorus in forest ecosystems: new insights from an ecosystem nutrition perspective. J Plant Nutr Soil Sci 179:129–135. https://doi.org/10.1002/jpln.201500541 CrossRefGoogle Scholar
- Lang F, Krüger J, Amelung W, Willbold S, Frossard E, Bünemann E, Bauhus J, Nitschke R, Kandeler E, Marhan S, Schulz S, Bergkemper F, Schloter M, Luster J, Guggisberg F, Kaiser K, Mikutta R, Guggenberger G, Polle A, Pena R, Prietzel J, Rodionov A, Talkner U, Meesenburg H, von Wilpert K, Hölscher A, Dietrich HP, Chmara I (2017) Soil phosphorus supply controls P nutrition strategies of beech forest ecosystems in Central Europe. Biogeochemistry. https://doi.org/10.1007/s10533-017-0375-0
- North PF (1976) Towards an absolute measurement of soil structural stability using ultrasound. J Soil Sci 27:451–459. https://doi.org/10.1111/j.1365-2389.1976.tb02014.x CrossRefGoogle Scholar
- Prietzel J, Harrington G, Häusler W, Heister K, Werner F, Klysubun W (2016a) Reference spectra of important adsorbed organic and inorganic phosphate binding forms for soil P speciation using synchrotron-based K-edge XANES spectroscopy. J Synchrotron Radiat 23:532–544. https://doi.org/10.1107/S1600577515023085 CrossRefPubMedGoogle Scholar
- Rasmussen C, Torn MS, Southard RJ (2005) Mineral assemblage and aggregates control carbon dynamics in a California conifer Forest. Soil Sci Soc Am J 69. https://doi.org/10.2136/sssaj2005.0040
- Ravel B, Newville M (2005) Athena, artemis, hephaestus: data analysis for X-ray absorption spectroscopy using IFEFFIT. J Synchrotron Rad 12:537–541. https://doi.org/10.1107/S0909049505012719
- R Core Team (2015) R: A language and environment for statistical computing. R Foundation for Statistical Computing, Vienna, Austria. http://www.R-project.org/
- Redfield AC (1958) The biological control of chemical factors in the environment. American scientist : the magazine of sigma XI, the scientific research. Society 46:205–221Google Scholar
- Saunders WMH, Williams EG (1955) Observations on the determination of total organic phosphorus in soils. J Soil Sci 6:254–267. https://doi.org/10.1111/j.1365-2389.1955.tb00849.x CrossRefGoogle Scholar
- Sinaj S, Frossard E, Fardeau JC (1997) Isotopically exchangeable phosphate in size fractionated and unfractionated soils. Soil Sci Soc Am J 61:1413. https://doi.org/10.2136/sssaj1997.03615995006100050019x CrossRefGoogle Scholar
- Stutz KP, Dann D, Wambsganss J, Scherer-Lorenzen M, Lang F (2017) Phenolic matter from deadwood can impact forest soil properties. Special issue on developments in soil organic phosphorus cycling in natural and agricultural. Ecosystems 288:204–212. https://doi.org/10.1016/j.geoderma.2016.11.014 Google Scholar