Philip Grabowski, Plant Soil and Microbial Sciences, Taylor University, Upland, IN, Sieglinde S. Snapp, Room A282, Michigan State University, East Lansing, MI, US, Cheryl A. Palm, Agricultural and Biological Engineering, University of Florida, Gainesville, FL, UNITED STATES, Mark Musumba, Jornada Experimental Range, New Mexico State University, Las Cruces, NM, Regis Chikowo, Box MP 167, Mount Pleasant, University of Zimbabwe, Harare, MI, ZIMBABWE and Mateete Bekunda, International Institute of Tropical Agriculture-Tanzania, Arusha, Tanzania, United Republic of