|ABDELRAHMAN, HAMADA - University Of Bari|
|Olk, Daniel - Dan|
|COCOZZA, CLAUDIO - University Of Bari|
|VENTRELLA, DOMINICO - Cropping Systems In Dry Environments Research Unit|
|MONTEMURRO, FRANCISCO - Study Of Cropping Systems Research Unit|
|MIANO, TEODORO - University Of Bari|
Submitted to: Book Chapter
Publication Type: Book / Chapter
Publication Acceptance Date: 10/9/2012
Publication Date: 2/4/2013
Citation: Abdelrahman, H.M., Olk, D.C., Cocozza, C., Ventrella, D., Montemurro, F.P., Miano, T. 2013. Integrated physical-chemical procedure for soil organic carbon frationation and characterization during transition to organic farming. In: Xu, J., Wu, J., He, Z., editors. Functions of Natural Organic Matter in a Changing Environment. Dordrecht, The Netherlands: Springer. p. 73-77.
Technical Abstract: Two field experiments in the South of Italy were established in 2009 to study and characterize SOM during transition to organic farming. Experiments included a cereal/leguminous rotation fertilized with permitted organic amendments with three replications. A sequential fractionation procedure was used to separate different SOM fractions: light fraction (LF), two size classes of particulate organic matter (POM), mobile humic acid (MHA), and Ca-bound humic acid (CaHA). Isolated fractions were quantified and analyzed for their C and N contents and carboohydrate and amino compound composition. The masses of the isolated fractions increased during a two-year course, with noticeable increases in LF and POM. Moreover, LF and POM were found more responsive than MHA to treatment and crop. The xylose/mannose ratio indicated that MHA-carbohydrates were mainly of microbial origin while LF- and POM-carbohydrates were of plant origin. Amino compounds constituted up to 30% of total soil N and were found to be more responsive to seasonal variation than to agronomic practices.