Mechanisms of macroaggregate stabilisation by carbonates: implications for organic matter protection in semi-arid calcareous soils

Soil Research - Tập 52 Số 2 - Trang 180 - 2014
Oihane Fernández‐Ugalde1,2, Iñigo Virto1, Pierre Barré3, Marcos Apesteguía4, Alberto Enrique1, M.J. Imaz1, Paloma Bescansa1
1Departamento Ciencias del Medio Natural, ETSIA, Universidad Pública de Navarra, 31006 Pamplona, Spain.
2Laboratoire de Géologie, École Normale Supérieure, 24 rue Lhomond, 75005 Paris, France.
3Laboratoire de Géologie, Ecole Normale Supérieure, 24 rue Lhomond, 75005, Paris, France
4Instituto Navarro de Tecnologías e Infraestructuras Agroalimentarias, SA, 31610 Villava, Spain.

Tóm tắt

Carbonates interfere with soil aggregation in semi-arid calcareous soils, promoting the stability of macroaggregates and decelerating the decomposition of the organic matter within them. Our aim was to determine the process through which carbonates participate in aggregation. We hypothesised (i) a tendency to accumulate reactive clay minerals via Ca2+ bridging, and (ii) a precipitation of carbonates within aggregates due to dissolution/re-precipitation phenomena. The <250-µm fractions of a Typic Calcixerept (CALC) and a decarbonated Calcic Haploxerept (DECALC) were incubated from the same agricultural field in semi-arid Spain with added maize straw during 28 days. A size-based fractionation was used to separate different aggregates in incubated and field-moist samples, and aggregates were analysed for organic C and maize-derived C, clay mineralogy by X-ray diffraction, and micromorphology in digital images of thin sections. Contrary to the first hypothesis, the two soils showed a similar tendency to accumulate smectite in aggregates, probably because the cation exchange capacity was saturated by Ca2+ in both CALC and DECALC. Macroaggregates showed a less porous structure in CALC than in DECALC due to the accumulation of calcite microcrystals, as formulated in the second hypothesis. We propose that low porosity of macroaggregates is mainly responsible for the slower turnover of organic matter observed in CALC than in DECALC. These results explain the greater concentration of organic C in microaggregates within macroaggregates in field-moist samples in CALC than in DECALC. The different porosity of macroaggregates may also result in differences in physical properties between CALC and DECALC. These observations suggest a different response of calcareous soils in terms of organic matter protection, resistance to erosion, and water storage compared with other soil types in semi-arid lands.

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Tài liệu tham khảo

Baldock, 2000, Organic Geochemistry, 31, 697, 10.1016/S0146-6380(00)00049-8

Baldock, 1994, Australian Journal of Soil Research, 32, 571, 10.1071/SR9940571

Barr�, 2007, Plant and Soil, 292, 137, 10.1007/s11104-007-9208-6

Barr�, 2008, Plant and Soil, 302, 213, 10.1007/s11104-007-9471-6

Bertrand, 2007, Soil Biology & Biochemistry, 39, 276, 10.1016/j.soilbio.2006.07.016

Boix-Fayos, 2001, Catena, 44, 47, 10.1016/S0341-8162(00)00176-4

Bouajila, 2008, Journal of Agronomy, 7, 127, 10.3923/ja.2008.127.137

Bronick, 2005, Geoderma, 124, 3, 10.1016/j.geoderma.2004.03.005

Catoni, 2012, Geoderma, 175, 17

Chenu, 1991, Soil Science Society of America Journal, 55, 1076, 10.2136/sssaj1991.03615995005500040030x

Cosentino, 2006, Soil Biology & Biochemistry, 38, 2053, 10.1016/j.soilbio.2005.12.022

De Gryze, 2005, Soil Biology & Biochemistry, 37, 55, 10.1016/j.soilbio.2004.07.024

De Gryze, 2006, Geoderma, 134, 82, 10.1016/j.geoderma.2005.09.002

Dechesne, 2008, Applied and Environmental Microbiology, 74, 5195, 10.1128/AEM.00313-08

Denef, 2005, European Journal of Soil Science, 56, 469, 10.1111/j.1365-2389.2004.00682.x

Denef, 2001, Soil Biology & Biochemistry, 33, 1599, 10.1016/S0038-0717(01)00076-1

Elliott, 1986, Soil Science Society of America Journal, 50, 627, 10.2136/sssaj1986.03615995005000030017x

Falsone, 2010, Agrochimica, 54, 1

Fern�ndez-Ugalde, 2011, Geoderma, 164, 203, 10.1016/j.geoderma.2011.06.008

Fern�ndez-Ugalde, 2013, European Journal of Soil Science

Harris, 2001, Soil Science Society of America Journal, 65, 1853, 10.2136/sssaj2001.1853

Hinsinger, 2009, Plant and Soil, 321, 117, 10.1007/s11104-008-9885-9

Kemmitt, 2008, Soil Biology & Biochemistry, 40, 61, 10.1016/j.soilbio.2007.06.021

Lanson, 1997, Clays and Clay Minerals, 45, 132, 10.1346/CCMN.1997.0450202

Le Bissonnais, 2007, European Journal of Soil Science, 58, 188, 10.1111/j.1365-2389.2006.00823.x

Muneer, 1989, Australian Journal of Soil Research, 27, 411, 10.1071/SR9890411

Oades, 1984, Plant and Soil, 76, 319, 10.1007/BF02205590

Rovira, 2008, Geoderma, 144, 517, 10.1016/j.geoderma.2008.01.006

Schj�nning, 1999, Geoderma, 89, 177, 10.1016/S0016-7061(98)00083-4

Shang, 2003, Biogeochemistry, 62, 177, 10.1023/A:1021123728639

Six, 1998, Soil Science Society of America Journal, 62, 1367, 10.2136/sssaj1998.03615995006200050032x

Six, 2002, Soil Science Society of America Journal, 66, 1981, 10.2136/sssaj2002.1981

Six, 2004, Soil & Tillage Research, 79, 7, 10.1016/j.still.2004.03.008

Strong, 2004, European Journal of Soil Science, 55, 739, 10.1111/j.1365-2389.2004.00639.x

Thomsen, 1999, Geoderma, 89, 199, 10.1016/S0016-7061(98)00084-6

Tisdall, 1982, Journal of Soil Science, 33, 141, 10.1111/j.1365-2389.1982.tb01755.x

Torn, 1997, Nature, 389, 170, 10.1038/38260

Virto, 2013, Spanish Journal of Soil Science, 3, 116