Effects of Grassland Fire on Selected Properties of Soil in the Savannah Region of Nigeria
Abdulraheem, K. A.1, Aremu, A. S. 1, Adeniran, J. A.2*, Yusuf, M. N. O. 2, Odediran, E.T. 2, Ismail, A. 3, Sonibare, J. A. 4
1Department of Civil Engineering, University of Ilorin, Ilorin, Nigeria
2 Environmental Engineering Research Laboratory, Department of Chemical Engineering, University of Ilorin, Ilorin, Nigeria
3Department of Water Resources and Environmental Engineering, Ahmadu Bello University, Zaria, Nigeria
4 Environmental Engineering Research Laboratory, Department of Chemical Engineering, Obafemi Awolowo University, Ile-Ife, Osun State, Nigeria
The effects of fire on soil properties have been widely studied in different ecosystems globally. However, only limited studies exist in the savanna tropics of Africa with mostly inconsistent results. The objective of this study is to characterize the effects of different fire intensities on soil properties in the Guinea Savannah of Nigeria through laboratory experiments. Three different grass species (Eleusine indica, Cynodon dactylon and Imperata cylindrica) and soils were collected from the forest zone of the University of Ilorin and prepared for laboratory investigation. Experimental fires were simulated in the laboratory to replicate field burning conditions on the prepared plots to determine precise effects of fire on soil properties. Three fire treatments (low, moderate and high) were considered, while the pre-burning and post burning samples of soils were taken for laboratory investigation, and the results statistically analyzed. The pH was observed to have increased between the range of 7.92 to 8.37. The average percentage decrease in organic matter content is 5%, 33% and 69% for low, moderate and high fire intensities, respectively. For total nitrogen, 8%, 16%, and 19% increase; calcium, 17%, 117% and 283% increase; magnesium, 11%, 30% and 84% increase; sodium, 7%, 20% and 54% increase; potassium, 24%, 20% and 49% decrease; available phosphorus, 8%, 18% and 29% increase. The results show the impacts of prescribed fire in the management of savanna ecosystem..
Keywords: Soil properties, Savannah fires, Organic matter, Fire intensity