Civil Engineering June 2022 | Vol 30 No 5

Civil Engineering June 2022 59 WHC = m soil, saturated – m soil, dry m soil, dry × 100[%] % improvement = ∆ WHC WHC of 0% sample × 100 RESULTS Figures 1, 2 and 3 show the effect that vermicompost (VC) and compost (C) had on the water holding capacities of loam, sandy and clay soils. The most notable improvements at the 10% vermicompost mix for loam, sandy and clay soils were 10.4%, 31.59% and –2.96% respectively. For the 10% compost mix the improvements were 19.65%, 27.39% and 0.16% respectively. CONCLUSION The results of this experiment showed that vermicompost can significantly increase the water holding capacities of loam and sandy soils. The 10% mix produced the largest improvements in loam and sandy soil, increasing the water holding capacity by 10.4% and 31.59% respectively. It was noted that no significant changes were observed in clay soils and vermicompost’s effect on clay soil may need to be studied further. This experiment provided promising results indicating that the use of ver- micompost in soils can save water, par- ticularly in the food production industry. This could potentially assist in improving food and water security in South Africa. PROJECT TEAM This experiment was conducted as part of a final year civil engineering investigational project undertaken by Ashley Megan Randall and Liam Macgregor and supervised by Dr Precious Biyela at the University of the Witwatersrand. Himkaar Singh from The Compost Kitchen was a valuable source of knowledge and vermicompost for this project.  SAICE National IP Showdown The civil engineering university research and investigation project is part of the national curriculum for final year civil engineering under- graduate students. Students are paired in teams of two and are required to select a current industry issue and conduct research in accordance with pre-set deliverables over a fixed period, leading up to their final year examina- tions. The teams then present their findings to a panel of judges, which comprises of both selected industry leaders and non-engineers. SAICE National Office has joined forces with the leading universities across the country to invite the winning teams from these regions to compete on a national level. The pres- entations are then adjudicated by: Q Q Identifying whether teams have gained an in-depth understanding of the research project Q Q Determining whether teams showcase adequate communication skills by presenting their work to a diverse audience Q Q Exposing these top students to the industry and to key players within the industry. The 2022 SAICE National IP Showdown, sponsored Sika, WorldsView, BVi, RIBCCS, and AF Consulting, took place in March at SAICE House in Midrand, Gauteng. Brendon Gova from the University of Pretoria came second, with his research on Assessing the Infiltration Characteristics of Urban Gardens . In third place was Mia Simon from Stellenbosch University, for her research on Using the Diffusion of Innovations Theory to Categorize Construction Industry Parties . Figure 1 Loam soil water holding capacities WHC (g/100g) Mix proportion 40 30 35 25 20 10 15 5 0 0% 5% VC 5% C 5% VC 10% C Figure 2 Sandy soil water holding capacities WHC (g/100g) Mix proportion 35 30 25 20 10 15 5 0 0% 5% VC 5% C 5% VC 10% C Figure 3 Clay soil water holding capacities WHC (g/100g) Mix proportion 48 46 47 45 44 42 43 41 39 40 0% 5% VC 5% C 5% VC 10% C