Hamada Abdelrahman, PhD
Associate Professor of Soil Chemistry and Fertility
Soil Science Dept., Faculty of Agriculture, Cairo University, Giza 12613 Egypt
Integrated physical-chemical procedure for soil organic carbon fractionation and characterization during transition to organic farming
- Citation:
- Integrated physical-chemical procedure for soil organic carbon fractionation and characterization during transition to organic farming, Abdelrahman, H. M., Olk D., Cocozza C., Venterella D., Montemurro F., and Miano T. , Functions of natural organic matter in changing environment, China, (2013) copy at www.tinyurl.com/y5c74zk7
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 amendments with three field replicates. 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 content and carbohydrates and amino compounds composition. The masses of the isolated fractions increased during 2-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 explained 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.