1 Department of Soil Science and Environment, Faculty of Agriculture, Environment, and Food Systems, University of Zimbabwe, Mount Pleasant, P. O. Box MP 167, Harare, Zimbabwe.
2 Department of Physics, Geography and Environmental Science, School of Natural Sciences, Great Zimbabwe University, Masvingo, Zimbabwe.
3 Department of Life and Consumer Sciences, School of Agriculture and Life Sciences, College of Agriculture and Environmental Sciences, University of South Africa, Pretoria, South Africa.
4 Department of Physical and Earth Sciences, Sol Plaatje University, Kimberley, 8301, South Africa.
5 Biosystems and Engineering Research Group, 380 New Adylin, Marlborough, Harare, Zimbabwe. wgwenzi@yahoo.co.uk.
6 Biosystems and Environmental Engineering Research Group, 380 New Adylin, Marlborough, Harare, Zimbabwe. wgwenzi@yahoo.co.uk.