Register      Login
Soil Research Soil Research Society
Soil, land care and environmental research
RESEARCH ARTICLE

Soil organic and organomineral fractions as indicators of the effects of land management in conventional and organic sugar cane systems

Carolina B. Brandani A C , Thalita F. Abbruzzini A , Richard T. Conant B and Carlos Eduardo P. Cerri A
+ Author Affiliations
- Author Affiliations

A Escola Superior de Agricultura ‘Luiz de Queiroz’, Universidade de São Paulo, Avenida Pádua Dias, 11, Piracicaba, São Paulo, CEP 13418-900, Brazil.

B Natural Resource Ecology Laboratory, Colorado State University, Fort Collins, CO 80523, USA.

C Corresponding author. Email: carolbrandani@yahoo.com.br

Soil Research 55(2) 145-161 https://doi.org/10.1071/SR15322
Submitted: 3 December 2014  Accepted: 18 March 2016   Published: 12 September 2016

Abstract

Brazilian sugar cane production has undergone changes in residue management. To better understand the dynamics of soil C and N in soil organic matter (SOM) fractions resulting from sugar cane management practices, we determined: the effects of different sugar cane management on the C and N content of SOM fractions; the effects of crop management, soil texture, depth and different organic matter additions on changes in 13C/12C and 15N/14N isotope composition; and the amount of SOC derived from different sources. Physical fractionation of SOM was performed for soils cultivated under four sugar cane managements, namely straw burning(SB), green cane (GC) and organic systems consisting of sugar cane grown under GC harvesting with high inputs of organic residues for 4 and 12 years (O-4 and O-12 respectively), as well as from a native vegetation (NV) area (Goianésia, Brazil). Ultrasonic dispersion of soil samples from 0–5, 5–10, 10–20 and 90–100-cm depths resulted in three organomineral fractions (<53, 75–53 and 2000–75 µm) and one organic fraction denoted as light fraction (2000–75 µm). C and N concentrations, 13C and 15N natural abundance and the proportion of C derived from C4 sugar cane plant residues (C-C4) were determined for each fraction. The C management index (CMI), derived from the total C pool and C lability, is useful in evaluating the capacity of management systems to improve soil quality and was calculated using the NV as the reference. Highest C and N concentrations were found for O-12 and O-4, mainly for the <53-µm organomineral fraction at 0–5 cm depth. The 13C and C-C4 values indicated a greater accumulation of C-C4 in SOM fractions in organic compared with burned and unburned systems. GC combined with organic management is a strategy for long-term storage of total C and N in the SOM fraction associated with <53-µm fraction and light fraction. In addition, the highest CMI and its positive relationship with C-C4 in O-12 suggest the role of this system to foster soil quality improvement. The results allow infer regarding the potential of management practices on C accumulation in SOM fractions, which, in turn, can be used as indicators of the effects of land management.

Additional keywords: burning straw, 13C, 15N, green cane, ultrasonic physical fractionation.


References

Anderson DW, Paul EA (1984) Organo-mineral complexes and their study by radiocarbon dating. Soil Science Society of America Journal 48, 298–301.
Organo-mineral complexes and their study by radiocarbon dating.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DyaL2cXitVyns7g%3D&md5=9b6583f702b9267a61af2e48e46d08e7CAS |

Baldock JA, Oades JM, Waters AG, Peng X, Vassallo AM, Wilson MA (1992) Aspects of the chemical-structure of soil organic materials as revealed by solid-state C13 NMR-spectroscopy. Biogeochemistry 16, 1–42.
Aspects of the chemical-structure of soil organic materials as revealed by solid-state C13 NMR-spectroscopy.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DyaK38XmsFSmsbs%3D&md5=f9a1467164d1bcf503ecb53dadaf8113CAS |

Barthès BG, Kouakoua E, Larré-Larrouy MC, Razafimbelo TM, De Luca EF, Azontonde A, Neves CSVJ, de Freitas PL, Feller CL (2008) Texture and sesquioxide effects on water-stable aggregates and organic matter in some tropical soils. Geoderma 143, 14–25.
Texture and sesquioxide effects on water-stable aggregates and organic matter in some tropical soils.Crossref | GoogleScholarGoogle Scholar |

Bernoux M, Cerri CC, Neill C, Moraes JFL (1998) The use of stable carbon isotopes for estimating soil organic matter turnover rates. Geoderma 82, 43–58.
The use of stable carbon isotopes for estimating soil organic matter turnover rates.Crossref | GoogleScholarGoogle Scholar |

Blair N (2000) Impact of cultivation and sugar-cane green trash management on carbon fractions and aggregate stability for a Chromic Luvisol in Queensland, Australia. Soil & Tillage Research 55, 183–191.
Impact of cultivation and sugar-cane green trash management on carbon fractions and aggregate stability for a Chromic Luvisol in Queensland, Australia.Crossref | GoogleScholarGoogle Scholar |

Blair GJ, Lefroy RDB, Lisle L (1995) Soil carbon fractions based on their degree of oxidation, and the development of a carbon management index for agricultural system. Australian Journal of Agricultural Research 46, 1459–1466.
Soil carbon fractions based on their degree of oxidation, and the development of a carbon management index for agricultural system.Crossref | GoogleScholarGoogle Scholar |

Blair GJ, Chapman L, Whitbread AM, Ball-Coelho B, Larsen P, Tiessen H (1998) Soil carbon changes resulting from trash management at two locations in Queensland, Australia and in north-east Brazil. Australian Journal of Soil Research 36, 873–882.
Soil carbon changes resulting from trash management at two locations in Queensland, Australia and in north-east Brazil.Crossref | GoogleScholarGoogle Scholar |

Bustamante MMC, Martinelli LA, Silva DA, Camargo PB, Klink CA, Domingues TFRV, Santos RV (2004) 15N natural abundance in woody plants and soils of central Brazilian savannas (Cerrado). Ecological Applications 14, S200–S213.
15N natural abundance in woody plants and soils of central Brazilian savannas (Cerrado).Crossref | GoogleScholarGoogle Scholar |

Cadisch G, Imhof H, Urquiaga S, Boddey RM, Giller KE (1996) Carbon turnover (13C) and nitrogen mineralization potential of particulate light soil organic matter after rainforest clearing. Soil Biology & Biochemistry 28, 1555–1567.
Carbon turnover (13C) and nitrogen mineralization potential of particulate light soil organic matter after rainforest clearing.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DyaK2sXjtFSqs7s%3D&md5=6c037dfc0f9cd432da42c6fe1f931578CAS |

Cambardella CA, Elliott ET (1994) Carbon and nitrogen dynamics of soil organic matter fractions from cultivated grassland soils. Soil Science Society of America Journal 58, 123–130.
Carbon and nitrogen dynamics of soil organic matter fractions from cultivated grassland soils.Crossref | GoogleScholarGoogle Scholar |

Canellas LPJ, Busatoa G, Dobbssa LB, Baldotto MA, Rumjanek VM, Olivares FL (2010) Soil organic matter and nutrient pools under long-term non-burning management of sugar cane. European Journal of Soil Science 61, 375–383.
Soil organic matter and nutrient pools under long-term non-burning management of sugar cane.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BC3cXot1artLY%3D&md5=ad8e74383c2963cbf858e5c4d71d5bb2CAS |

Cherubin MR, Franco ALC, Cerri CEP, Pavinato PS, Rodrigues M, Davies CA, Cerri CC (2015) Sugarcane expansion in weathered Brazilian soils: phosphorus pools as indicators of environmental impacts from land-use change. Ecological Indicators 211, 173–184.

Christensen BT (1992) Physical fractionation of soil and organic matter in primary particle-size and density separates. Advances in Soil Science 20, 1–90.
Physical fractionation of soil and organic matter in primary particle-size and density separates.Crossref | GoogleScholarGoogle Scholar |

Christensen BT (2001) Physical fractionation of soil and structural and functional complexity in organic matter turnover. European Journal of Soil Science 52, 345–353.
Physical fractionation of soil and structural and functional complexity in organic matter turnover.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BD3MXntFKiu74%3D&md5=2e68b2d01739bd99ccd2924aae623db9CAS |

Christensen BT, Sorensen LH (1985) The distribution of native and labeled carbon between soil particle size fractions isolated from long-term incubation experiments. Journal of Soil Science 36, 219–229.
The distribution of native and labeled carbon between soil particle size fractions isolated from long-term incubation experiments.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DyaL2MXltVeqt78%3D&md5=0ca9d2111d13d2b3985c180bd8f3986aCAS |

Companhia Nacional de Abastecimento (2013) Acompanhamento de safra brasileira: cana-de-açúcar, segundo levantamento, agosto/2013. (Companhia Nacional de Abastecimento: Brasília). Available at http://www.conab.gov.br/OlalaCMS/uploads/arquivos/13_08_08_09_39_29_boletim_cana_portugues_-_abril_2013_1o_lev.pdf [verified 2 August 2016].

Conceição PC, Boeni M, Dieckow J, Bayer C, Mielniczuk J (2008) Fracionamento densimétrico com politungstato de sódio no estudo da proteção física da matéria orgânica em solos. Revista Brasileira de Ciencia do Solo 32, 541–549.
Fracionamento densimétrico com politungstato de sódio no estudo da proteção física da matéria orgânica em solos.Crossref | GoogleScholarGoogle Scholar |

Day RP 1965. Pipette method of particle size analysis. In ‘Methods of soil analysis. Agronomy Volume 9’. pp. 553–562. (ASA)

Del Galdo I, Six J, Peressotti A, Cotrufo MF (2003) Assessing the impact of land-use change on soil C sequestration in agricultural soils by means of organic matter fractionation and stable C isotopes. Global Change Biology 9, 1204–1213.
Assessing the impact of land-use change on soil C sequestration in agricultural soils by means of organic matter fractionation and stable C isotopes.Crossref | GoogleScholarGoogle Scholar |

Dieckow J, Mielniczuk J, González-Vila FJ, Knicker H, Bayer C (2006) No-till cropping systems and N fertilisation influences on organic matter composition of physical fractions of a subtropical Acrisol as assessed by analytical pyrolysis (Py-GC/MS). Geoderma 135, 260–268.
No-till cropping systems and N fertilisation influences on organic matter composition of physical fractions of a subtropical Acrisol as assessed by analytical pyrolysis (Py-GC/MS).Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BD28XhtVykt7rE&md5=9ff9fdd0d921e4c5d0fabc168bd628f3CAS |

Diochon AC, Kellman L (2009) Physical fractionation of soil organic matter: destabilization of deep soil carbon following harvesting of a temperate coniferous forest. Journal of Geophysical Research 114, G01016.
Physical fractionation of soil organic matter: destabilization of deep soil carbon following harvesting of a temperate coniferous forest.Crossref | GoogleScholarGoogle Scholar |

Dominy CS, Haynes RJ, van Antwerpen R (2002) Loss of soil organic matter and related soil properties under long-term sugarcane production on two contrasting soils. Biology and Fertility of Soils 36, 350–356.
Loss of soil organic matter and related soil properties under long-term sugarcane production on two contrasting soils.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BD38XovVWgsLc%3D&md5=806aec8436a3d89d3452048eed79fa2bCAS |

Ellert BH, Bettany JR (1995) Calculation of organic matter and nutrients stored in soils under contrasting management regimes. Canadian Journal of Soil Science 75, 529–538.
Calculation of organic matter and nutrients stored in soils under contrasting management regimes.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DyaK28XhslKlsbo%3D&md5=7968dea26af896ba5ed90a6f59803b69CAS |

Empresa Brasileira de Pesquisa Agropecuária (EMBRAPA) (1979) ‘Manual de método de análise de solo.’ (EMBRAPA: Rio de Janeiro)

FAO (2015) World reference base for soil resources 2014. International soil classification system for naming soils and creating legends for soil maps. Available at http://www.fao.org/3/a-i3794e.pdf [verified 16 August 2016].

Feller C, Beare MH (1997) Physical control of soil organic matter dynamics in the tropics. Geoderma 79, 69–116.
Physical control of soil organic matter dynamics in the tropics.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DyaK2sXns1Cmu7k%3D&md5=7414de0ef104049ec779e9b9cc92a829CAS |

Franzluebbers AJ (2010) Achieving soil organic carbon sequestration with conservation agricultural systems in the southeastern United States. Soil Science Society of America Journal 74, 347–357.
Achieving soil organic carbon sequestration with conservation agricultural systems in the southeastern United States.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BC3cXjtFWrtL8%3D&md5=9544ea352331a87f960840e915a70e7bCAS |

Freixo AA, Machado PLOA, Guimarães CM, Silva CA, Fadigas FS (2002) Estoques de carbono e nitrogênio e distribuição de frações orgânicas de Latossolo do Cerrado sob diferentes sistemas de cultivo. Revista Brasileira de Ciencia do Solo 26, 425–434.
Estoques de carbono e nitrogênio e distribuição de frações orgânicas de Latossolo do Cerrado sob diferentes sistemas de cultivo.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BD38XmtVSnsL0%3D&md5=2388511c67696ab6f85a1cb17d06fb4dCAS |

Galdos MV, Cerri CC, Cerri CEP (2009) Soil carbon stocks under burned and unburned sugarcane in Brazil. Geoderma 153, 347–352.
Soil carbon stocks under burned and unburned sugarcane in Brazil.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BD1MXht1Gnt7rM&md5=3a58a622d385fa2dc5a442844471ea38CAS |

Galdos MV, Cerri CC, Cerri CEP, Paustian K, van Antwerpen R (2010) Simulation of sugarcane residue decomposition and aboveground growth. Plant and Soil 326, 243–259.
Simulation of sugarcane residue decomposition and aboveground growth.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BD1MXhsFGrt7bO&md5=7144c391d9db27a61f4eaa5f94244a1eCAS |

Gee GW, Bauder JW (1986) Particle-size analysis. In ‘Methods of soil analysis. Physical and mineralogical methods. Agronomy Monograph 9’. 2nd edn. (Ed. A Klute) pp. 383–411. (American Society of Agronomy: Madison, WI)

Golchin A, Oades JM, Skjemstad JO, Clarke P (1994) Study of free and occluded particulate organic matter in soils by solid state 13C CP/MAS NMR spectroscopy and scanning electron microscopy. Australian Journal of Soil Research 32, 285–309.
Study of free and occluded particulate organic matter in soils by solid state 13C CP/MAS NMR spectroscopy and scanning electron microscopy.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DyaK2cXjt1ajs74%3D&md5=d237dad824e1eb2da1c337954c7722bcCAS |

Hassink J (1997) The capacity of soils to preserve organic C and N by their association with clay and silt particles. Plant and Soil 191, 77–87.
The capacity of soils to preserve organic C and N by their association with clay and silt particles.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DyaK2sXltVKju7g%3D&md5=73a71a4af747a2e71b507ef827cd39b8CAS |

Högberg P (1997) Tansley review no. 95: 15N natural abundance in soil–plant systems. New Phytologist 137, 179–203.
Tansley review no. 95: 15N natural abundance in soil–plant systems.Crossref | GoogleScholarGoogle Scholar |

Hurlbert SH (1984) Pseudoreplication and the design of ecological field experiments. Ecological Monographs 54, 187–211.
Pseudoreplication and the design of ecological field experiments.Crossref | GoogleScholarGoogle Scholar |

Jobbágy EG, Jackson RB (2000) The vertical distribution of soil organic carbon and its relation to climate and vegetation. Ecological Applications 10, 423–436.
The vertical distribution of soil organic carbon and its relation to climate and vegetation.Crossref | GoogleScholarGoogle Scholar |

John B, Yamashita T, Ludwig B, Flessa H (2005) Storage of organic carbon in aggregate and density fractions of silty soils under different types of land use. Geoderma 128, 63–79.
Storage of organic carbon in aggregate and density fractions of silty soils under different types of land use.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BD2MXlvV2ksL4%3D&md5=0fa91b4ffbdd79e599706cc388cdc2ffCAS |

Kramer MG, Sollins P, Sletten RS, Swart PK (2003) N isotope fractionation and measures of organic matter alteration during decomposition. Ecology 84, 2021–2025.
N isotope fractionation and measures of organic matter alteration during decomposition.Crossref | GoogleScholarGoogle Scholar |

Krull ES, Bestland EA, Gates WP (2002) Soil organic matter decomposition and turnover in a tropical Ultisol: evidence from δ13C, δ15N and geochemistry. Radiocarbon 44, 93–112.
Soil organic matter decomposition and turnover in a tropical Ultisol: evidence from δ13C, δ15N and geochemistry.Crossref | GoogleScholarGoogle Scholar |

Lal R (2004) Soil carbon sequestration to mitigate climate change. Geoderma 123, 1–22.
Soil carbon sequestration to mitigate climate change.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BD2cXoslSmsLY%3D&md5=356f2cc64a47d40a835666ff7faa58aaCAS |

Machado Pinheiro ÉF, Lima E, Ceddia MB, Urquiaga S, Alves BJR, Boddey RM (2010) Impact of pre-harvest burning versus trash conservation on soil carbon and nitrogen stocks on a sugarcane plantation in the Brazilian Atlantic forest region. Plant and Soil 333, 71–80.
Impact of pre-harvest burning versus trash conservation on soil carbon and nitrogen stocks on a sugarcane plantation in the Brazilian Atlantic forest region.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BC3cXovFCjt74%3D&md5=8f1abd42764a9748d8c54568c0ae1ba5CAS |

Marschner B, Brodowski S, Dreves A, Gleixner G, Gude A, Grootes PM, Hamer U, Heim A, Jand G, Ji R, Kaiser K, Kalbitz K, Kramer C, Leinweber P, Rethemeyer J, Schäffer A, Schmidt MWI, Schwark L, Wiesenberg GLB (2008) How relevant is recalcitrance for the stabilization of organic matter in soils? Journal of Plant Nutrition and Soil Science 171, 91–110.
How relevant is recalcitrance for the stabilization of organic matter in soils?Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BD1cXisFyhurw%3D&md5=d4eed1d318036eef4de03253a620c383CAS |

Mendonça LAR, Frischkorn H, Santiago MF, Camargo PB, Lima JOG, Mendes Filho J (2010) Identificação de mudanças florestais por 13C e 15N dos solos da Chapada do Araripe, Ceará. Revista Brasileira de Engenharia Agrícola e Ambiental Campina Grande 14, 314–319.

Mikutta R, Kleber M, Torn MS, Jahn R (2006) Stabilization of soil organic matter: association with minerals or chemical recalcitrance? Biogeochemistry 77, 25–56.
Stabilization of soil organic matter: association with minerals or chemical recalcitrance?Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BD28XhsFCkur0%3D&md5=058b7ea75f25fdaa4d9648718dc96b11CAS |

Nelson DW, Sommers LE (1996) Total carbon, organic carbon, and organic matter. In ‘Methods of soil analysis. Part 2’. 2nd edn. (Eds AL Page, PA Helmke, RH Loeppert, PN Soluanpour, MA Tabatabai, CT Johnston, ME Sumner) pp. 961–1010. (American Society of Agronomy, Inc.: Madison, WI)

Newman A (2014) Effect of sugarcane residue management on soil organic carbon in a Louisiana agricultural system: implications for carbon sequestration. M.Sc. Thesis, Louisiana State University, Baton Rouge.

Pinheiro ÉFM, Pereira MG, Anjos LHC, Machado PLOA (2004) Fracionamento densimétrico da matéria orgânica do solo sob diferentes sistemas de manejo e cobertura vegetal em Paty do Alferes (RJ). Revista Brasileira de Ciência do Solo 28, 731–737.
Fracionamento densimétrico da matéria orgânica do solo sob diferentes sistemas de manejo e cobertura vegetal em Paty do Alferes (RJ).Crossref | GoogleScholarGoogle Scholar |

Plaza C, Courtier-Murias D, Fernández JM, Polo A, Simpson AJ (2013) Physical, chemical, and biochemical mechanisms of soil organic matter stabilization under conservation tillage systems: a central role for microbes and microbial by-products in C sequestration. Soil Biology & Biochemistry 57, 124–134.
Physical, chemical, and biochemical mechanisms of soil organic matter stabilization under conservation tillage systems: a central role for microbes and microbial by-products in C sequestration.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BC3sXitVGmu70%3D&md5=9643df76c1287b93e26f007ad9b5080eCAS |

Post WM, Kwon KC (2000) Soil carbon sequestration and land-use change: processes and potential. Global Change Biology 6, 317–327.
Soil carbon sequestration and land-use change: processes and potential.Crossref | GoogleScholarGoogle Scholar |

Rachid CTCC, Piccolo MC, Leite DCA, Balieiro FC, Coutinho HLC, Van Elsas JD, Peixoto RS, Rosado AS (2012) Physical–chemical and microbiological changes in Cerrado soil under differing sugarcane harvest management systems. Biomedcentral Microbiology 12, 170–181.

Rangel OJP, Silva CA (2007) Estoques de carbono e nitrogênio e frações orgânicas de latossolo submetido a diferentes sistemas de uso e manejo. Revista Brasileira de Ciência do Solo 31, 1609–1623.
Estoques de carbono e nitrogênio e frações orgânicas de latossolo submetido a diferentes sistemas de uso e manejo.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BD1cXis1ehtL0%3D&md5=0cc7cc4486666fb7bd5281a37b09d92dCAS |

Razafimbelo T, Chevallier T, Albrecht A, Chapuis-Lardy L, Rakotondrasolo FN, Michellon R, Rabeharisoa L, Bernoux M (2013) Texture and organic carbon contents do not impact amount of carbon protected in Malagasy soils. Scientia Agricola 70, 204–208.
Texture and organic carbon contents do not impact amount of carbon protected in Malagasy soils.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BC3sXhsVaqsbjE&md5=86fd333c8f6af16b8822ea22f81aa7d6CAS |

Roscoe R, Buurman P (2003) Tillage effects on soil organic matter in density fractions of a Cerrado Oxisol. Soil and Tillage Research 70, 107–119.
Tillage effects on soil organic matter in density fractions of a Cerrado Oxisol.Crossref | GoogleScholarGoogle Scholar |

Roscoe R, Buurman P, Velthorst EJ (2000) Disruption of soil aggregate by different amounts of ultrasonic energy in SOM fractionation of a clay Latosol: carbon, nitrogen, and 13C distribution in particle-size fractions. European Journal of Soil Science 51, 445–454.
Disruption of soil aggregate by different amounts of ultrasonic energy in SOM fractionation of a clay Latosol: carbon, nitrogen, and 13C distribution in particle-size fractions.Crossref | GoogleScholarGoogle Scholar |

Roscoe R, Buurman P, Velthorst EJ, Vasconcellos CA (2001) Soil organic matter dynamics in density and particle-size fractions as revealed by the 13C/12C isotopic ratio in a Cerrado’s Oxisol. Geoderma 104, 185–202.
Soil organic matter dynamics in density and particle-size fractions as revealed by the 13C/12C isotopic ratio in a Cerrado’s Oxisol.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BD3MXnsFGht7g%3D&md5=0ffce8bd4959df8d293381a575a8b108CAS |

Rossi CQ, Pereira MG, Loss A, Gazolla PR, Perin A, dos Anjos LHC (2013) Changes in soil C and N distribution assessed by natural 13C and 15N abundance in a chronosequence of sugarcane crops managed with pre-harvest burning in a Cerrado area of Goiás, Brazil. Agriculture, Ecosystems & Environment 170, 36–44.
Changes in soil C and N distribution assessed by natural 13C and 15N abundance in a chronosequence of sugarcane crops managed with pre-harvest burning in a Cerrado area of Goiás, Brazil.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BC3sXmsFantbw%3D&md5=1af3e6ec22940cb04c645497ada6e154CAS |

Schmidt MWI, Noack AG (2000) Black carbon in soils and sediments: analysis, distribution, implications, and current challenges. Global Biogeochemical Cycles 14, 777–793.
Black carbon in soils and sediments: analysis, distribution, implications, and current challenges.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BD3cXmsVymt7s%3D&md5=a0cce1426f159f62555f09a23c6bcfb9CAS |

Six J, Elliott ET, Paustian K (2000) Soil macroaggregate turnover and microaggregate formation: a mechanism for C sequestration under no-tillage agriculture. Soil Biology and Biochemistry 32, 2099–2103.
Soil macroaggregate turnover and microaggregate formation: a mechanism for C sequestration under no-tillage agriculture.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BD3MXpvFWg&md5=702a0ec96ecb00d0f479a945097cd8adCAS |

Six J, Conant RT, Paul EA, Paustian K (2002) Stabilization mechanisms of soil organic matter: implications for C-saturation of soils. Plant and Soil 241, 155–176.
Stabilization mechanisms of soil organic matter: implications for C-saturation of soils.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BD38XltV2jsbo%3D&md5=0a3cfa5658de1509067a636dfda3c288CAS |

Sollins P, Homann P, Caldwell BA (1996) Stabilization and destabilization of soil organic matter: mechanisms and controls. Geoderma 74, 65–105.
Stabilization and destabilization of soil organic matter: mechanisms and controls.Crossref | GoogleScholarGoogle Scholar |

Stewart CE, Plante AF, Paustian K, Conant RT, Six J (2008) Soil carbon saturation: linking concept and measurable carbon pools. Soil Science Society of America Journal 72, 379–392.
Soil carbon saturation: linking concept and measurable carbon pools.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BD1cXjsFynsLY%3D&md5=79f493cf4004a1d54c7787dc439c8b7bCAS |

Swanstson CW, Caldwell BA, Homann PS, Ganio L, Sollins P (2002) Carbon dynamics during a long-term incubation of separate and recombined density fractions from seven forest soils. Soil Biology & Biochemistry 34, 1121–1130.
Carbon dynamics during a long-term incubation of separate and recombined density fractions from seven forest soils.Crossref | GoogleScholarGoogle Scholar |

Taiz L, Zeiger E (2004) ‘Fisiologia vegetal.’ 3rd edn. (Artmed: Porto Alegre)

Tan Z, Lal R, Owens L, Izaurrald RC (2007) Distribution of light and heavy fractions of soil organic carbon as related to land use and tillage practice. Soil & Tillage Research 92, 53–59.
Distribution of light and heavy fractions of soil organic carbon as related to land use and tillage practice.Crossref | GoogleScholarGoogle Scholar |

Thorburn PJ, Meier EA, Collins K, Robertson FA (2012) Changes in soil carbon sequestration, fractionation and soil fertility in response to sugarcane residue retention are site-specific. Soil & Tillage Research 120, 99–111.
Changes in soil carbon sequestration, fractionation and soil fertility in response to sugarcane residue retention are site-specific.Crossref | GoogleScholarGoogle Scholar |

Tiessen H, Stewart JWB (1983) Particle size fractions and their use in studies of soil organic matter. Cultivation effects on organic matter composition in size fractions. Soil Science Society of America Journal 47, 509–514.
Particle size fractions and their use in studies of soil organic matter. Cultivation effects on organic matter composition in size fractions.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DyaL3sXks12ntb4%3D&md5=524e161302a6895b5f5e78c00620288eCAS |

Tiessen H, Karamanos RE, Stewart JWB, Sclles F (1984) Natural nitrogen-15 abundance as an indicator of soil organic matter transformations in native and cultivated soils. Soil Science Society of America Journal 48, 312–315.
Natural nitrogen-15 abundance as an indicator of soil organic matter transformations in native and cultivated soils.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DyaL2cXitVyntLk%3D&md5=293b3cea65f885a75eb4d9611b64294eCAS |

Tivet F, Sá JCM, Lal R, Borszowskei PR, Briedis C, Santos JB, Sá MFM, Hartman DC, Eurich G, Farias A, Bouzinac S, Séguy L (2013) Soil organic carbon fraction losses upon continuous plow-based tillage and its restoration by diverse biomass-C inputs under no-till in sub-tropical and tropical regions of Brazil. Geoderma 209–210, 214–225.
Soil organic carbon fraction losses upon continuous plow-based tillage and its restoration by diverse biomass-C inputs under no-till in sub-tropical and tropical regions of Brazil.Crossref | GoogleScholarGoogle Scholar |

Umrit G, Cheong RN, Gillabel J, Merck R (2014) Effect of conventional versus mechanized sugarcane cropping systems on soil organic carbon stocks and labile carbon pools in Mauritius as revealed by 13C natural abundance. Plant and Soil 379, 177–192.
Effect of conventional versus mechanized sugarcane cropping systems on soil organic carbon stocks and labile carbon pools in Mauritius as revealed by 13C natural abundance.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BC2cXivVenu7o%3D&md5=07c810f770c1d05cb2ba1811eafc83e9CAS |

Vieira FCB, Bayer C, Zanatta JA, Dieckow J, Mielniczuk J, He ZL (2007) Carbon management index based on physical fractionation of soil organic matter in an Acrisol under long-term no-till cropping systems. Soil & Tillage Research 96, 195–204.
Carbon management index based on physical fractionation of soil organic matter in an Acrisol under long-term no-till cropping systems.Crossref | GoogleScholarGoogle Scholar |

Virto I, Moni C, Swanston C, Chenu C (2010) Turnover of intra- and extra-aggregate organic matter at the silt-size scale. Geoderma 156, 1–10.
Turnover of intra- and extra-aggregate organic matter at the silt-size scale.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BC3cXjt1Kgsb0%3D&md5=cf7845df3c6a7196de8d1ded66ac8784CAS |

Vitorello VA, Cerri C, Andreux F, Feller C, Victória RL (1989) Organic matter and natural 13C distribution in forest and cultivated Oxisols. Soil Science Society of America Journal 53, 773–778.
Organic matter and natural 13C distribution in forest and cultivated Oxisols.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DyaL1MXlsFalurw%3D&md5=425ea1516821642b64a197068a8fc2edCAS |

von Lützow M, Kögel-Knabner I, Ekschmitt K, Flessa H, Guggenberger G, Matznere E, Marschner B (2007) SOM fractionation methods: relevance to functional pools and to stabilization mechanisms. Soil Biology & Biochemistry 39, 2183–2207.
SOM fractionation methods: relevance to functional pools and to stabilization mechanisms.Crossref | GoogleScholarGoogle Scholar |

Wiseman CLS, Püttmann W (2005) Soil organic carbon and its sorptive preservation in central Germany. European Journal of Soil Science 56, 65–76.
Soil organic carbon and its sorptive preservation in central Germany.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BD2MXitFGit70%3D&md5=7d23282a90c955e9303fe363e85a7cafCAS |