Menas Wuta

Smallholder farmers across sub-Saharan Africa increasingly invest in small-scale irrigation to improve agricultural productivity and enhance livelihoods. Unlike conventional top-down irrigation development, these investments are typically incremental and adaptive, reflecting changing environmental and socio-economic conditions. However, limited empirical evidence exists on how farmers make irrigation investment decisions in practice, particularly in sand river systems where groundwater stored in sandy riverbeds provides a critical seasonal water source. This study presents the Sand River Game, a board-based serious game designed to simulate irrigation investment decision-making and facilitate dialogue on irrigation development pathways. The game was tested with irrigating farmers along the Tuli River in Zimbabwe and the Enguli River in Kenya, two contexts where farmer-led irrigation development is expanding. Gameplay revealed diverse irrigation investment pathways shaped by contextual factors such as access to credit, market opportunities, and perceptions of risk. Farmers experimented with irrigation technologies, crop choices, and risk-management strategies. Post-game reflections highlighted trade-offs related to energy costs, water availability, and collective marketing. The findings demonstrate how serious gaming can support experiential learning and dialogue around irrigation investment decisions and provide a practical tool for grounding the concept of Adaptive Investment Pathways in smallholder irrigation development along sand rivers.

Background: Wild foods and geophagic material are important in the nutrition of communities along Zimbabwe’s Great Dyke, a serpentinic ultramafic (SUG) and surrounding granitic geological (GG) environment. However, the health risks associated with consumption of these in terms of toxic geogenic contaminants (TGC) is largely unknown. The study objective was to evaluate the health risks associated with consuming wild foods and geophagic materials from these environments. Methods: Health risk assessments were determined using the hazard quotient, hazard index (HI) and life cancer risk (LCR) for 10 TGCs in wild foods and geophagic material. Results: High human health risks (HI ≥ 1) were found in six wild foods and geophagic material under the SUG environment compared with five wild foods and geophagic material under the GG environment. Wild foods and geophagic materials exceeded the tolerable risk level of 1 × 10⁻⁴. Their LCR values ranged from 2.11 × 10⁻¹ to 6.83 × 10⁻⁷. All TGCs had high LCR values above the tolerable risk level, except for Cu, Fe, Mn and Zn. Conclusions: Infusion reduced the LCR values for TGCs, with only Pb in the GG environment decreasing to below tolerable risk level. Communities should apply selective consumption and avoid F. sycomorus and geophagic materials with cancer risks.

Lake Chivero, a vital water resource for Harare, Zimbabwe, and surrounding communities. It draws its water from three main urban centres, Harare, Chitungwiza and Ruwa. These urban areas are characterised by poor environmental governance, which has led to soil and water pollution, sedimentation, and deforestation. The main objectives of the review centre on the lake’s status, water quality, drivers of contamination, policy contexts, and opportunities for repair to establish habitability through inclusive governance. The review also analyses the frameworks and methodologies employed by the reviewed studies and reports. This systematic review includes 109 peer- reviewed articles, policy-related documents from 2005 to 2025, and community-based reports spanning the past two decades. The review examines how stakeholder engagement, gendersensitive approaches, and indigenous knowledge are integrated into environmental governance through interdisciplinary methods, including socio-hydrology and political ecology. It evaluates studies with empirical data and transparent methods, excluding those lacking an environmental governance context. Findings show declining water levels, increased nutrients, and microbial contamination from urban and agricultural sources, driven by sewage, land-use changes, and climate variability. Institutional fragmentation and limited participation hinder progress. The review advocates for reforms via multi-level governance and stresses the importance of inclusive, adaptive strategies. It underscores the urgency of coordinated efforts to restore Lake Chivero and safeguard its ecosystem services amid climate change and urban growth.

Wild foods and geophagic material are important in the nutrition of communities along Zimbabwe’s Great Dyke, a serpentinic ultramafic (SUG) and surrounding granitic geological (GG) environment. However, the health risks associated with consumptions of these in terms of toxic geogenic contaminants (TGC) is largely unknown. The study objective was to evaluate the health risks associated with consuming wild foods and geophagic materials from these environments. Health risk assessments were determined using Hazard Quotient, Hazard Index (HI) and Life Cancer Risk (LCR) for 10 TGCs, in wild foods and geophagic material. High human health risks (HI ≥ 1) were found in six wild foods and geophagic material under the SUG environment, compared with five wild foods and geophagic material under the GG environment. Wild foods and geophagic materials exceeded the tolerable risk level of 1x10-4. Their LCR values ranged from 1.22 x 10-3 to 8.77 × 10-2. All TGCs had a high LCR values above the tolerable risk level, except for Cu, Fe, Mn and Zn. Infusion reduced the LCR values for TGCs with only Pb in GG environment decreasing to below tolerable risk level. Communities should apply selective consumption and avoid F. sycomorus and geophagic materials with cancer risks.

Smallholder farmers in sub-Saharan Africa are increasingly exposed to risks such as erratic rainfall, prolonged dry spells, and frequent droughts that threaten sustainable crop production. This study assessed the effectiveness of dead level contours with innovations (DLC INN), dead level contours with infiltration pits (DLC INFIL), dead level contours with open channels (DLC OPEN) and standard graded contours (SGCs) in harvesting and storing water in the channel, and improving crop conditions during the critical stages of maize growth on different soil textural groups in the Zvishavane District of Zimbabwe. The DLC INFIL, DLC OPEN and DLC INN outperformed the SGC under medium- and heavy-textured soils, with yields ranging between 1.7 and 2.36 t/ha compared to 0.9 t/ha for the SGC. For light textured soils, the DLC INN had the highest maize yield, averaging 0.8 t/ha. On heavy textured soils using DLC INN, DLC INFIL and DLC OPEN, smallholder farmers may use a spacing interval of 24–27 m. On medium textured soils, DLC INN and DLC INFIL can be used at a spacing interval of 18–21 m and 12 to 15 m with DLC OPEN. On light textured soils, farmers are advised to invest in DLC INN only, using a spacing interval of 12–15 m.

Smallholder farmers in sub-Saharan Africa are increasingly exposed to risks such as erratic rainfall, prolonged dry spells, and frequent droughts that threaten sustainable crop production. This study assessed the effectiveness of dead level contours with innovations (DLC INN), dead level contours with infiltration pits (DLC INFIL), dead level contours with open channels (DLC OPEN) and standard graded contours (SGCs) in harvesting and storing water in the channel, improving crop conditions during the critical stages of maize growth on different soil textural groups in the Zvishavane District of Zimbabwe. The DLC INFIL, DLC OPEN and DLC INN outperformed the SGC under medium- and heavy-textured soils, with yields ranging between 1.7 and 2.36 t/ha compared to 0.9 t/ha for the SGC. For light textured soils, the DLC INN had the highest maize yield, averaging 0.8 t/ha. On heavy textured soils using DLC INN, DLC INFIL and DLC OPEN, smallholder farmers may use a spacing interval of 24–27 m. On medium textured soils, DLC INN and DLC INFIL can be used at a spacing interval of 18–21 m and 12 to 15 m with DLC OPEN. On light textured soils, farmers are advised to invest in DLC INN only, using a spacing interval of 12–15 m.

Planting basins are an important soil and water conservation technology. This study evaluated the effects of basins on soil organic carbon (SOC) stocks, aggregate stability (Ima), bulk density, soil moisture retention and sorghum yield in agro-ecological regions III, IV and V of Chipinge district. The experiment consisted of three treatments; namely planting basins (basins) with goat manure and inorganic fertilizer application, hand hoeing with similar fertility amendments (FP+) and hand hoeing without fertility amendments (FP). It was hypothesized that planting basins with fertility amendments would improve the selected soil quality parameters and sorghum yield. Only planting basins significantly (p˂0.05) improved soil quality parameters in the 0-15 cm depth and bulk density, Ima, SOC stocks ranged from 1356 to 1451 kg/m3; 314 to 450 and 14.18 to 25.55 Mg ha-1 respectively. Planting basins significantly increased (p130% in all the 3 agro-ecological regions. The hypothesis was accepted and it was concluded that basins improve soil properties and sorghum grain yield in agro-ecological regions III, IV and V. Considering the soil and crop productivity benefits highlighted in this study, there is a strong justification for the widespread promotion and adoption of planting basins in semi-arid agro-ecological regions of Zimbabwe.