SEGH Articles

SEGH2018 Prize Winners Series: Mumba Mwape

20 August 2018
Winner of a Best Poster Prize at SEGH2018: Selection and design of irrigation systems in Zambia - this installment of the Prize Winners Series is contributed by Mumba Mwape.


Mumba R. Mwape1, Derek M. Heeren2,3, Dean Eisenhauer3, Aaron Mittelstet2,3 and Laszlo Hayde4

1: Zambia Agricultural Research Institute, Zambia, 2: University of Nebraska-Lincoln, USA, 3: Robert Daugherty Water for Food Global Institute, USA, 4: IHE-Delft Institute for Water Education, Netherlands

Zambia has been making various reforms aimed at improving the agriculture sector for the past two decades. Recent developments have seen a streamlined focus on irrigation as a means of increasing production and productivity to bring about sustainability in the agriculture sector, which had previously been dependant on rainfall. These efforts have been directed at small-scale farmers who have been impacted by reduced rainfall due to climate variability. The high cost of irrigation equipment and the urgent need to increase food production entails that irrigation plans guarantee sustainability, effectiveness and efficiency. This research was aimed at evaluating the suitability and viability of community irrigation systems, and designing systems for two sites (of 60 ha each) in Masaiti and Samfya in agro-ecological region III of the country using surface (river) and ground (well) water sources respectively.


 Field infiltration test (taking readings)


In establishing the suitability of the areas, soil tests such as infiltration and texture analyses were conducted as well as the depth of the soils. The quality of water was assessed for different parameters for toxicity levels that may restrict water use in irrigated agriculture. To determine the quantity of water, a pumping test was carried out for ground water while 20 year monthly flow rates of the river were used for surface water. Land and water availability were also assessed. Aquacrop was used to determine the crop water requirements and the yield potentials and based on the yield potential results, the most profitable crops with the least water requirements were selected. The soil tests showed high infiltration rates of 10 cm/hr and 11.6 cm/hr for Masaiti and Samfya respectively. This led to the recommendation of only sprinkler and drip irrigation systems. The pumping test gave a potential yield of 110 l/s while the river’s 20-year average flow rate gave 2 m3/s and 26.6 m3/s as the lowest and highest rate respectively. The quality of the water from both sites was found to have no restriction to agricultural use according Food and Agriculture Organization (FAO) standards. The crops selected, for a 60 ha irrigation system, had a water requirement of 50.8 l/s when water is not limited and 34.5 l/s if staggered planting dates are used. This water requirement can be supplied by both sources that were analysed, up to 2 irrigation systems by the well and 9 irrigation systems if 25% of the river’s lowest flow rate is diverted for use. The land tenure system in the area is customary and farm sizes per household was between 5->50 ha and while cultivation was less than 10% of the total area owned. The economic analysis of the irrigation development for a center pivot and drip irrigation system gave a positive outlook with an improvement in yield of 65% to more than 100% and with a profit margin per ha approximately 10 times more than the profit of current production practices.  

Keep up to date

Submit Content

Members can keep in touch with their colleagues through short news and events articles of interest to the SEGH community.

Science in the News

Latest on-line papers from the SEGH journal: Environmental Geochemistry and Health

  • Retraction Note: Field evaluation of intensive compost application on Cd fractionation and phytoavailability in a mining-contaminated soil 2019-06-18

    The Editor-in-Chief has retracted this article (Li et al. 2016). An investigation by the Journal has not been able to confirm the identity and affiliation of the author David Raleve. This author was the corresponding author on submission but changed the corresponding authorship at the proof stage. The current corresponding author was not aware of the publication of this article. As the appropriate authorship for this article cannot be determined, the Editor-in-Chief no longer has confidence in this article. Ibrahim Mohamed disagrees with this retraction. Ming Li and Wenli Chen did not respond to any correspondence about this retraction. Qiaoyun Huang did not respond to any correspondence about this retraction notice.

  • Perlite as the partial substitute for organic bulking agent during sewage sludge composting 2019-06-18


    Composting is an efficient and cost-effective technology for sewage sludge treatment, and bulking agents are essential in sewage sludge composting. In this study, perlite was chosen as inorganic bulking agent to partially substitute for the organic bulking agent. Variations in the temperature, bulk density, moisture content, pH, electrical conductivity, organic carbon, nitrogen, phosphorus and potassium were detected during sewage sludge composting. The treatment with a mass ratio of spent mushroom substrate to perlite at 3:1 exhibited the highest pile temperature and the best effect on reducing bulk density and moisture content. In addition, Fourier transform infrared spectra showed that perlite promotes the degradation of organic matter during the composting process, and the germination index showed that the compost from all treatments was safe for agricultural application. When the mass ratios of spent mushroom substrate and perlite at 3:1 and 2:2 were chosen as bulking agents, the sewage sludge compost product could be used to produce plant cultivation substrate, and economic benefits could be obtained from sewage sludge composting according to comprehensive cost analysis.

  • A scoping study of component-specific toxicity of mercury in urban road dusts from three international locations 2019-06-18


    This scoping study presents an investigation of the total and bioaccessible mercury concentrations in road dust (RD) from three international urban sites, where a one-off sampling campaign was conducted at each. This was done to address the hypothesis that the matrix in which mercury is found influences its ability to become accessible to the body once inhaled. For that purpose, the samples were analysed for total and pulmonary bioaccessible mercury and the data compared to the chemical structure of individual particles by SEM. The results obtained from this study suggest that a high mercury content does not necessarily equate to high bioaccessibility, a phenomenon which could be ascribed to the chemical character of the individual particles. It was found that the Manchester samples contained more pulmonary soluble mercury species (as determined by elemental associations of Hg and Cl) in comparison to the other two samples, Curitiba, Brazil, and Johannesburg, South Africa. This finding ultimately underlines the necessity to conduct a site-specific in-depth analysis of RD, to determine the concentration, chemical structure and molecular speciation of the materials within the complex matrix of RD. Therefore, rather than simply assuming that higher bulk concentrations equate to more significant potential human health concerns, the leaching potential of the metal/element in its specific form (for example as a mineral) should be ascertained. The importance of individual particle behaviour in the determination of human health risk is therefore highlighted.