VIHSCM related Articles

Effects of drainage intensity on water and nitrogen use efficiency and rice grain yield in a semi-arid marshland in Rwanda

2023-02-15T15:53:05Z

Effects of drainage intensity on water and nitrogen use efficiency and rice grain yield in a semi-arid marshland in Rwanda Tuyishime, Olive; Abraham, Joel; Messing, Ingmar; Francois, Naramabuye; Sankaranarayanan, Muthiah; Wesström, Ingrid Drainage management is important in intensification of irrigated paddy rice production. This studyassessed the effects of drainage intensity on water and nitrogen use efficiency and rice grain yield inafield experiment conducted during three seasons in Rwanda. The experiment comprised 12 plotswith four blocks and three treatments: DS0.6(0.6 m deep drain), DD11.2(1.2 m deep drain, controlstructure open four times per week), and DD21.2(1.2 m deep drain, control structure open two timesper week). Outflow was calculated from water balance. Nitrogen (N) content in drainage water wasdetermined weekly. Crop yield and N uptake were determined in grain and straw.In all seasons, grain yield was 61–131% higher, crop N uptake was 24–90% higher, harvest index(HI) was 24–65% higher and water use efficiency (WUE) was 50–150% higher in treatments DD11.2and DD21.2than in DS0.6. There was a decrease in soil carbon/nitrogen ratio at the end of Seasons 2and 3. Recirculating straw tofields is thus necessary to replenish SOC for long-term soil fertility. Apractical implication of the study is that managed deep drainage systems could enhance water useefficiency and rice grain yield in poorly drained paddyfields Journal article

Deep Drainage Lowers Methane and Nitrous Oxide Emissions from Rice Fields in a Semi-Arid Environment in Rwanda

2023-02-15T12:15:54Z

Deep Drainage Lowers Methane and Nitrous Oxide Emissions from Rice Fields in a Semi-Arid Environment in Rwanda Tuyishime, Olive; Strömgren, Monika; Joel, Abraham; Messing, , Ingmar; Naramabuye, Francois Xavier; Wesström, Ingrid Few studies have explored greenhouse gas (GHG) emissions from arable land in subSaharan Africa (SSA), and particularly from rice paddy fields, which can be a major source of methane (CH4 ) and nitrous oxide (N2O) emissions. This study examined the effect of drainage on CH4 and N2O emissions from rice fields in Rwanda under shallow drainage to 0.6 m, with the drain weir open four times per week, and deep drainage to 1.2 m with the weir open four times or two times per week. CH4 and N2O fluxes from the soil surface were measured on nine occasions during rice flowering and ripening, using a closed chamber method. Measured fluxes made only a minor contribution to total GHG emissions from rice fields. However, drainage depth had significant effects on CH4 emissions, with shallow drainage treatment giving significantly higher emissions (~0.8 kg ha−1 or ~26 kg CO2 -equivalents ha−1 ) than deep drainage (0.0 kg) over the 44-day measurement period. No treatment effect was observed for N2O fluxes, which ranged from low uptake to low release, and were generally not significantly different from zero, probably due to low nitrogen (N) availability in soil resulting from low N fertilization rate (in the region). Overall, the results suggest that deep drainage can mitigate CH4 emissions compared with traditional shallow drainage, while not simultaneously increasing N2O emissions Journal article

Management strategies for banana Xanthomonas wilt in Rwanda include mixing indigenous and improved cultivars

2023-02-15T12:13:38Z

Management strategies for banana Xanthomonas wilt in Rwanda include mixing indigenous and improved cultivars Uwamahoro, Florence; Berlin, Anna; Bylund, Helena; Bucagu, Charles; Yuen, Jonathan Xanthomonas wilt is a major constraint to banana production in the East and Central Africa. The disease can cause up to 100% yield losses if proper management strategies are not well implemented. Understanding of disease status, driving factors and farmers’ knowledge provide insights towards a sustainable management approach. A total of 120 and 150 banana farms from eight and ten districts of Rwanda were surveyed for disease occurrence in 2015 and 2016 respectively. The owners of the farms were interviewed about disease knowledge, management practices, and source of information in these aspects. The results show that Xanthomonas wilt was present in all surveyed districts with high incidence (above 45% in both 2015 and 2016) in major banana growing areas, highlighting the risk of increasing yield losses. High anthomonas wilt incidence and severity was associated with Impara and Eastern plateau agro-ecological zones, intercropping systems, brewing bananas, dense spacing, and homogenous cultivars. Here, we demonstrate for the first time the gravity of Xanthomonas wilt in major banana growing areas of Rwanda. This agrees with the finding that proper implementation of management practices by the farmers remains limited. Disease management difficulties could be attributed to inaccessibility to the right information since some information sources may be unreliable. We also report for the first time that fields with a mixture of indigenous and improved cultivars are likely to have low Xanthomonas wilt disease severity (p < 0.005), and this could be considered in banana Xanthomonas wilt management package. Our findings are essential to understand the urgency of improving extension services with updated practices and reinforcing disease monitoring efforts in order to stop new infections and further spread of the Xanthomonas wilt disease, a threat to sustainable banana production in Rwanda. Journal article

Insights into vaccine hesitancy from systems thinking, Rwanda

2022-03-09T15:03:40Z

Insights into vaccine hesitancy from systems thinking, Rwanda Decouttere, Catherine; Banzimana, Stany; Davidsen, Pål; Van Riet, Carla; Vandermeulen, Corinne; Mason, Elizabeth; Jalali S., Mohammad; Vandaele, Nico To investigate vaccine hesitancy leading to underimmunization and a measles outbreak in Rwanda and to develop a conceptual, community-level model of behavioural factors. Local immunization systems in two Rwandan communities (one recently experienced a measles outbreak) were explored using systems thinking, human-centred design and behavioural frameworks. Data were collected between 2018 and 2020 from: discussions with 11 vaccination service providers (i.e. hospital and health centre staff); interviews with 161 children’s caregivers at health centres; and nine validation interviews with health centre staff. Factors influencing vaccine hesitancy were categorized using the 3Cs framework: confidence, complacency and convenience. A conceptual model of vaccine hesitancy mechanisms with feedback loops was developed. A comparison of service providers’ and caregivers’ perspectives in both rural and peri-urban settings showed that similar factors strengthened vaccine uptake: (i) high trust in vaccines and service providers based on personal relationships with health centre staff; (ii) the connecting role of community health workers; and (iii) a strong sense of community. Factors identified as increasing vaccine hesitancy (e.g. service accessibility and inadequate follow-up) differed between service providers and caregivers and between settings. The conceptual model could be used to explain drivers of the recent measles outbreak and to guide interventions designed to increase vaccine uptake. The application of behavioural frameworks and systems thinking revealed vaccine hesitancy mechanisms in Rwandan communities that demonstrate the interrelationship between immunization services and caregivers’ vaccination behaviour. Confidence-building social structures and context-dependent challenges that affect vaccine uptake were also identified Journal article