Abstract
Assessment of particulate (>53-μm) and mineral-associated (<53-μm) soil organic matter (SOM) fractions is a useful approach to understand the dynamic of organic matter in soils. This study aimed to compare the long-term (9-yr) effects of no-tillage (NT) and conventional tillage (CT) on C and N stocks in the two above mentioned organic fractions in a Brazilian Acrisol. The degree of SOM humification, which has been associated with the concentration of semiquinone-type free radicals (`spin') determined by electron spin resonance (ESR), was also evaluated. Soil under no-tillage had 7.55 Mg ha−1 (25%) more C and 741 kg ha−1 (29%) more N than conventionally tilled soil in the 0–175-mm depth. Both particulate and mineral-associated SOM increased in the no-tilled soil. The increase of C and N stocks in the mineral-associated SOM accounted for 75% and 91% of the difference in total soil C and N stocks between NT and CT, respectively. Averaged across tillage systems, C and N stocks were respectively 4.6 and 16.8 times higher in the mineral-associated SOM than in particulate SOM. The higher C and N stocks were associated with greater recalcitrance of mineral-associated SOM to biological decomposition, resulting, probably, from its interaction with variable charge minerals. This is corroborated by a positive relationship between concentrations of C and iron oxides and kaolinite in the 53–20, 20–2 and <2-μm particle size classes, of the 0–25-mm soil layer. The degree of SOM humification, assessed by ESR, decreased in both the 53–20 and 20–2-μm fractions under NT. However, it was unaffected by tillage in the <2-μm fraction, which normally presented the lowest `spin' concentration. Since quality as well as quantity of SOM improved in the no-tillage soil, adoption of this system is highly recommended for amelioration of degraded tropical and subtropical soils.
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References
Arshad, M A, Schnitzer M, Angers D A, Ripmeester J A 1990 Effects of till vs no-till on the quality of soil organic matter. Soil Biol. Biochem. 22, 595–599.
Baldock J A, Oades J M, Waters A G, Peng X, Vassalo A M and Wilson M A 1992 Aspects of the chemical structure of soil organic matter material as revealed by solid-state 13C NMR spectroscopy. Biogeochemistry 16, 1–42.
Balesdent J, Chenu C and Balabane M 2000 Relationship of soil organic matter dynamics to physical protection and tillage. Soil Till. Res. 53, 215–230.
Bayer C 1996 Dinâmica da matéria orgânica em sistemas de manejo de solos. Tese de Doutorado, Universidade Federal do Rio Grande do Sul, Porto Alegre: 241 pp.
Bayer C, Martin-Neto L, Mielniczuk J and Ceretta C A 2000 Effect of no-till cropping systems on soil organic matter in a sandy clay loam Acrisol from Southern Brazil monitored by electron spin resonance and nuclear magnetic resonance. Soil Till. Res. 53, 95–104.
Bayer C, Martin-Neto L, Mielniczuk J, Pillon C N and Sangoi L 2001 Changes in soil organic matter fractions under subtropical no-till cropping systems. Soil Sci. Soc. Amer. J. 65, 1473–1478.
Beare M H, Cabrera M L, Hendrix P F and Coleman D C 1994 Aggregate-protected and unprotected organic matter pools in conventional-and no-tillage soils. Soil Sci. Soc. Amer. J. 58, 787–795.
Bremer E, Ellert B H and Janzen H H 1995 Total and light-fraction carbon dynamics during four decades after cropping changes. Soil Sci. Soc. Am. J. 59, 1398–1403.
Cambardella C A and Elliot E T 1992 Particulate soil organic-matter changes across a grassland cultivation sequence. Soil Sci. Soc. Amer. J. 56, 777–783.
Carter M R, Angers D A and Kunelius H T 1994 Soil structure and organic matter fractions under perennial grasses. Soil Sci. Soc. Am. J. 58, 1194–1199.
Chan K Y 1997 Consequences of changes in particulate organic carbon in vertisols under pasture and cropping. Soil Sci. Soc. Amer. J. 61, 1376–1382.
Christensen B T 1992 Physical fractionation of soil and organic-matter in primary particle size and density separates. Adv. Soil Sci. 20, 2–90.
Franzluebbers A J and Arshad M A 1997 Particulate organic carbon content and potential mineralization as affected by tillage and texture. Soil Sci. Soc. Amer. J. 61, 1382–1386.
Golchin A, Oades J M, Skjemstad J O and Clarke P 1994 Soil structure and carbon cycling. Aust. J. Soil Res. 32, 1043–1068.
Killham K, Amato M, Ladd J N 1993 Effect of subtrate location in soil and soil pore-water regime on carbon turnover. Soil Biol. Biochem. 25, 57–62.
Lal R, Follet R F, Kimble J and Cole C V 1999 Managing U.S. cropland to sequester carbon in soil. J. Soil Wat. Conserv. 5, 374–381.
Martin-Neto L, Andriulo A E and Tragheta D 1994 Effects of cultivation on ESR spectrum of organic matter from soil size fractions of a mollisol. Soil Sci. 157, 365–372.
McGill W B and Myers R J K 1987 Controls on dynamics of soil and fertilizer nitrogen. In Soil Fertility and Organic matter as Critical Components of Production Systems. Eds. R F Follet, J W B Stewart and C V Cole. pp 73–99. SSSA/ASA, Madison, WI.
Mehra J A and Jackson M L 1960 Iron oxides removal from soils and clays by a dithionite-citrate system buffered with sodium bicarbonate. Clay Clays Miner. 5, 317–327.
Nelson P W and Sommers C E 1982 Total carbon, organic carbon and organic matter. In Methods of soil analysis. Ed. A L Page. pp 539–579. Madison: SSSA, Pt. 2 (SSSA, Agronomy Monograph, 9).
Powlson D S, Brookes P C and Christensen B T 1987 Measurement of soil microbial biomass provides an early indication of changes in total soil organic matter due to straw incorporation. Soil Biol. Biochem. 19, 159–164.
Reicosky D C, Kemper W D, Langdale G W, Douglas D L and Rasmussen P E 1995 Soil organic matter changes resulting from tillage and biomass production. J. Soil Wat. Conserv. 50, 253–261.
Riffaldi R and Schnitzer M 1972 Electron spin resonance spectrometry of humic substances. Soil Sci. Soc. Am. Proc. 36, 301–305.
Rivero C, Senesi N, Paolini J and Orazio V D 1998 Characteristics of humic acids of some Venezuelan soils. Geoderma 81, 227–239.
Shang C and Tiessen H 1998 Organic matter stabilization in two semiarid tropical soils, size, density and magnetic separations. Soil Sci. Soc. Am. J. 62, 1247–1257.
Six J, Elliot E T, Paustian J and Doran J W 1998 Aggregation and soil organic matter accumulation in cultivated and native grassland soils. Soil Sci. Soc. Am. J. 62, 1367–1377.
Six J, Elliot E T and Paustian K 1999 Aggregate and soil organic matter dynamics under conventional and no-tillage systems. Soil Sci. Soc. Am. J. 63, 1350–1358.
Skjemstad J O, Janik L J, Heads M J and McClure S G 1993 High energy ultraviolet photo-oxidation, a novel technique for studying physically protected organic matter in clay-and silt-sized aggregates. J. Soil Sci. 44, 485–499.
Sollins P, Homann P and Caldwell B A 1996 Stabilization and destabilization of soil organic matter, mechanisms and controls. Geoderma 74, 65–105.
Tisdall J M and Oades J M 1982 Organic matter and water-stable aggregates in soils. J. Soil Sci. 33, 141–163.
Vanlauwe B, Aman S, Aihou K, Tossah B K, Adebiyi V, Sanginga N, Lyasse O, Diels J and Merckx R 1999 Alley cropping in the moist savanna of West-Africa III. Soil organic matter fractionation and soil productivity. Agrof. Systems 42, 245–264.
Wander M M, Bidart M G and Aref S 1998 Tillage impacts on depth distribution of total and particulate organic matter in three Illinois Soils. Soil Sci. Soc. Am. J. 62, 1704–1711.
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Bayer, C., Mielniczuk, J., Martin-Neto, L. et al. Stocks and humification degree of organic matter fractions as affected by no-tillage on a subtropical soil. Plant and Soil 238, 133–140 (2002). https://doi.org/10.1023/A:1014284329618
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DOI: https://doi.org/10.1023/A:1014284329618