ABSTRACT
For the past 100 years, the Wadi Laba floods have been and are still the only source of the essential nutrients for the low-lying irrigated fields. During the water management reform interventions, it was assumed that the Wadi Laba floods deliver sufficient nutrients and that there is no need for any artificial fertility replenishment. This assumption is, however, merely based on the fact that nutrient deficiency symptoms have not been observed. It is imperative to note that slight and moderate nutrient deficiency symptoms could go unnoticed and sometimes be confused with other complex field events, such as salt damage, disease and drought (Jones, 2003). Thus, it is only by conducting systematic soil and water analysis (this was done in this research) that one can conclusively determine whether or not the Wadi Laba floods have been and are still supplying the needed quantity and quality of nutrients for the above noted optimum sorghum production.
