Research Article
Soil Enzymes Activities in Irrigated and Rain-Fed Vertisols of the Semi-Arid Tropics of Sudan
Department of Soil and Environment Sciences, Faculty of Agriculture, University of Khartoum, P.O. Box 32, Shambat, Sudan
Uwe Langer
Department of Soil Ecology, Helmholtz Centre for Environmental Research-UFZ, Theodor-Lieser-Street 4, 06112 Halle, Germany