Organic farming can overcome the environmental consequences of intensive conventional farming. The objective of the work was to investigate the changes in labile soil organic matter (SOM) fractions during the conversion from conventional to organic farming in two Italian sites, namely Foggia (FG) and Metaponto (MT), which differed mainly in initial soil organic carbon (SOC) content. Fields were cultivated with lentil and wheat in rotation and treated with either compost or nitrogen or phosphorus (N/P) fertilizers in three field replicates. The SOM was sequentially fractionated into light fraction (LF), particulate organic matter (POM), and mobile humic acid (MHA) fraction. Isolated fractions were quantified and analyzed for C and N contents. Although total SOC responded to the fertilization treatments, the LF and POM fractions were yet more responsive. The MHA represented on average of 15% of SOC at both sites; however, the LF represented only 5–6% of the total SOC but was the most responsive to changes in soil management. Compost application contributed significantly greater quantities of LF, POM, and MHA than did the N/P fertilizers application. The initial SOC content can play an important role in determining the impacts of introducing organic farming practices on SOM fractions. Although both sites had an initial low SOC content, the MT site, with a lower SOC content, showed a substantial fractional C increment as compared to the FG site.
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Abdelrahman HM, Olk DC, Dinnes D, Ventrella D, Miano T, Cocozza C (2016) Occurrence and abundance of carbohydrates and amino compounds in sequentially extracted labile soil organic matter fractions. J Soils Sediments 16:2375–2384. https://doi.org/10.1007/s11368-016-1437-y
Abdelrahman HM, Cocozza C, Olk DC, Ventrella D, Miano T (2017) Carbohydrates and amino compounds as short-term indicators of soil management. Clean 45:1–8. https://doi.org/10.1002/clen.201600076
Arcand MM, Lemke R, Farrell RE, Knight JD (2013) Nitrogen supply from belowground residues of lentil and wheat to a subsequent wheat crop. Biol Fertil Soils 50:507–515. https://doi.org/10.1007/s00374-013-0873-8
Bakken AK, Breland TA, Haraldsen TK, Aamlid TS, Sveistrup TE (2006) Soil fertility in three cropping systems after conversion from conventional to organic farming. Acta Agr Scand B-S P 56:81–90. https://doi.org/10.1080/09064710510029150
Briar SS, Miller SA, Stinner D, Kleinhenz MD, Grewal PS (2011) Effects of organic transition strategies for peri-urban vegetable production on soil properties, nematode community, and tomato yield. Appl Soil Ecol 47:84–91. https://doi.org/10.1016/j.apsoil.2010.12.001
Cao XY, Olk DC, Chappell M, Cambardella CA, Miller LF, Mao JD (2011) Solid-state NMR analysis of soil organic matter fractions from integrated physical–chemical extraction. Soil Sci Soc Am J 75:1374–1384. https://doi.org/10.2136/sssaj2010.0382
Clark MS, Horwath WR, Shennan C, Scow KM (1998) Changes in soil chemical properties resulting from organic and low-input farming practices. Agron J 90:662–671. https://doi.org/10.2134/agronj1998.00021962009000050016x
Clark MS, Horwath WR, Shennan C, Scow KM, Lantni WT, Ferris H (1999) Nitrogen, weeds and water as yield-limiting factors in conventional, low-input, and organic tomato systems. Agric Ecosyst Environ 73:257–270. https://doi.org/10.1016/S0167-8809(99)00057-2
Commission Regulation (EC) No 889/2008 of 5 September 2008 laying down detailed rules for the implementation of Council Regulation (EC) No 834/2007 on organic production and labelling of organic products with regard to organic production, labelling and control
Cotrufo MF, Wallenstein MD, Boot CM, Denef K, Paul E (2013) The microbial efficiency-matrix stabilization (MEMS) framework integrates plant litter decomposition with soil organic matter stabilization: do labile plant inputs form stable soil organic matter? Glob Change Biol 19:988–995. https://doi.org/10.1111/gcb.12113
de Jesus Souza B, Lopes do Carmo D, Silva Santos RH, Senna de Oliveira T, Fernandes RBA (2019) Residual contribution of green manure to humic fractions and soil fertility. J Soil Sci Plant Nutr 19:878–886. https://doi.org/10.1007/s42729-019-00086-z
De Mastro F, Brunetti G, Traversa A, Cocozza C (2019) Effect of crop rotation, fertilisation and tillage on main soil properties and its water extractable organic matter. Soil Res 57:365–373. https://doi.org/10.1071/SR18297
Frasier I, Quiroga A, Fernández R, Álvarez C, Gómez F, Scherger E, Gili A, Noellemeyer E (2019) Soil type, land-use and -management as drivers of root-C inputs and soil C storage in the semiarid pampa region, Argentina. Soil Till Res 192:134–143. https://doi.org/10.1016/j.still.2019.05.010
Gan YT, Liang BC, Liu LP, Wang XY, McDonald CL (2011) C:N ratios and carbon distribution profile across rooting zones in oilseed and pulse crops. Crop Pasture Sci 62:496–503. https://doi.org/10.1071/CP10360
Gomiero T, Pimentel D, Paoletti MG (2011) Environmental impact of different agricultural management practices: conventional vs. organic agriculture. CRC Crit Rev Plant Sci 30:95–124. https://doi.org/10.1080/07352689.2011.554355
Gopinath KA, Saha S, Mina BL, Pande H, Srivastva AK, Gupta HS (2009) Bell pepper yield and soil properties during conversion from conventional to organic production in Indian Himalayas. Sci Hortic 122:339–345. https://doi.org/10.1016/j.scienta.2009.05.016
Gregorich EG, Monreal CM, Schnitzer M, Schulten HR (1996) Transformation of plant residues into soil organic matter; chemical characterization of plant tissue, isolated soil fraction, and whole soils. Soil Sci 161:680–693. https://doi.org/10.2136/sssaj2005.0116
Gregorich EG, Beare MH, McKim UF, Skjemstad JO (2006) Chemical and biological characteristics of physically uncomplexed organic matter. Soil Sci Soc Am J 70:975–985. https://doi.org/10.2136/sssaj2005.0116
Halberg N (2012) Assessment of the environmental sustainability of organic farming: definitions, indicators and the major challenges. Can J Plant Sci 92:981–996. https://doi.org/10.4141/cjps2012-035
Hassink J (1997) The capacity of soils to preserve organic C and N by their association with clay and silt particles. Plant Soil 191:77–87. https://doi.org/10.1023/A:1004213929699
Haynes RJ (2005) Labile organic matter fractions as central components of the quality of agricultural soils: an overview. Adv Agron 85:221–268. https://doi.org/10.1016/s0065-2113(04)85005-3
Herencia J, Ruiz J, Melero S, Garcia Galavís P, Maqueda C (2008) A short-term comparison of organic v. conventional agriculture in a silty loam soil using two organic amendments. J Agr Sci 146:677–687. https://doi.org/10.1017/S0021859608008071
Janzen HH, Campbell CA, Ellert BH, Bremer E (1997) Soil organic matter dynamics and their relationship to soil quality. In: Carter MR (ed) Gregorich EG. Elsevier, Soil quality for crop production and ecosystem health, pp 277–291
Karasawa T, Takebe M, Sato F, Komada M, Nagaoka K, Takenaka M, Urashima Y, Nishimura S, Takahashi S, Kato N (2015) Trends of lettuce and carrot yields and soil enzyme activities during transition from conventional to organic farming in an andosol. Soil Sci Plant Nutr 61:295–311. https://doi.org/10.1080/00380768.2014.985577
Le THX, Marschner P (2018) Mixing organic amendments with high and low C/N ratio influences nutrient availability and leaching in sandy soil. J Soil Sci Plant Nutr 18:952–964. https://doi.org/10.4067/S0718-95162018005002703
Mandal A, Toor A, Dhaliwal S (2019) Assessment of sequestered organic carbon and its pools under different agricultural land-uses in the semi-arid soils of South-Western Punjab, India. J Soil Sci Plant Nutr:1–15. https://doi.org/10.1007/s42729-019-00137-5
Marriott EE, Wander MM (2006) Total and labile soil organic matter in organic and conventional farming systems. Soil Sci Soc Am J 70:950–959. https://doi.org/10.2136/sssaj2005.0241
Nandwani D, Nwosisi S (2016) Global trends in organic agriculture. In Nandwani D (ed) Organic farming for sustainable agriculture, Springer, 1–35
Olk DC (2006) A chemical fractionation for structure-function relations of soil organic matter in nutrient cycling. Soil Sci Soc Am J 70:1013–1022. https://doi.org/10.2136/sssaj2005.0108
Romanyà J, Casals P (2019) Biological nitrogen fixation response to soil fertility is species-dependent in annual legumes. J Soil Sci Plant Nutr:1–11. https://doi.org/10.1007/s42729-019-00144-6
Santos VB, Araújo ASF, Leite LFC, Nunes LAPL, Melo WJ (2012) Soil microbial biomass and organic matter fractions during conversion from conventional to organic farming systems. Geoderma 170:227–231. https://doi.org/10.1016/j.geoderma.2011.11.007
Sherrod LA, Dunn G, Peterson GA, Kolberg RL (2002) Inorganic carbon analysis by modified pressure - calcimeter method. Soil Sci Soc Am J 66:299–305. https://doi.org/10.2136/sssaj2002.2990
Six J, Conant RT, Paul EA, Paustian K (2002) Stabilization mechanisms of soil organic matter: implications for C-saturation of soils. Plant Soil 241:155–176. https://doi.org/10.1023/A:1016125726789
Soil Survey Staff (1999). Soil taxonomy: A basic system of soil classification for making and interpreting soil surveys. 2nd edition. Natural Resources Conservation Service. U.S. Department of Agriculture Handbook 436
Stamou GP, Tsiafouli MA, Monokrousos N, Sgardelis SP, Papatheodorou EM, Argyropoulou MD (2011) The study of secondary successional patterns in soil using network analysis: the case of conversion from conventional to organic farming. Pedobiologia 54:253–259. https://doi.org/10.1016/j.pedobi.2011.03.006
Trigalet S, Oost KV, Roisin C, van Wesemael B (2014) Carbon associated with clay and fine silt as an indicator for SOC decadal evolution under different residue management practices. Agric Ecosyst Environ 196:1–9. https://doi.org/10.1016/j.agee.2014.06.011
Varvel GE, Wilhelm WW (2011) No-tillage increases soil profile carbon and nitrogen under long-term rainfed cropping systems. Soil Till Res 114:28–36. https://doi.org/10.1016/j.still.2011.03.005
Yang F, Tian J, Fang H, Gao Y, Xu M, Lou Y, Zhou B, Kuzyakov Y (2019) Functional soil organic matter fractions, microbial community, and enzyme activities in a mollisol under 35 years manure and mineral fertilization. J Soil Sci Plant Nutr 19:430–439. https://doi.org/10.1007/s42729-019-00047-6
Zinati GM (2002) Conversion from conventional to organic farming systems: I. challenges, recommendations, and guidelines for pest management. HortTechnology 12:606–610. https://doi.org/10.21273/HORTTECH.12.4.606
The Egyptian Ministry of Higher Education (MoHE) is acknowledged for financing the visit of H. Abdelrahman to the University of Bari, Italy. This research was carried out in the framework of the BIO.INNOVA project financed by the Ministero della Politiche Agricole Alimentari e Forestali, Italy.
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Abdelrahman, H., Cocozza, C., Olk, D.C. et al. Changes in Labile Fractions of Soil Organic Matter During the Conversion to Organic Farming. J Soil Sci Plant Nutr 20, 1019–1028 (2020). https://doi.org/10.1007/s42729-020-00189-y
- Light fraction
- Particulate organic matter
- Mobile humic acids
- Crop rotation