ABSTRACT
The weights of light fraction organic matter (LF) separated from soils using saturated CaCl2 solution (1.4 g cm−3) were compared to those separated using NaI solution (1.6 g cm−3 and 1.4 g cm−3) to examine the possibility of using CaCl2 solution for LF separation, to examine more cost-effective LF separation procedure. In terms of the recovery weight and carbon and nitrogen content, the LF characteristics of 19 samples of the plow layer or A horizon soils separated using CaCl2 solution were similar to those of LF separated using NaI solution (1.6 g cm−3), which is commonly used for LF analysis. These results suggest that CaCl2 solution could be used for LF analysis. The applicability of the CaCl2 separation procedure for the analysis of LF from soil containing charcoal material was further confirmed by examining another set of 16 samples of the plow layer. The recovery weights of LF from soil containing organic matter and charcoal material with CaCl2 solution were similar to those with sodium polytungstate (1.6 g cm−3), which is conventionally used not only for LF but also for charcoal material separation from soils.
Acknowledgments
The authors are grateful to the staff members of the agricultural experiment institute and universities and to farmers for supplying soil samples and field information. We also thank Drs. Shinya Funakawa, Hitoshi Shinjo, Kazumichi Fujii, and Mr. Makoto Tatsumi for their assistance in soil sampling. We also appreciate Dr Rota Wagai for his constructive comments on this manuscript. We would like to thank Editage (www.editage.com) for English language editing.
Disclosure statement
No potential conflict of interest was reported by the author(s).