Climate Change

Climate Change

 

 

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Africa is the continent most vulnerable to the impacts of climate change. It is already experiencing increased incidences of drought and flood. AfricaRice and its partners have paid considerable attention to climate change and its effects on the rice sector in Africa.

 

Research of AfricaRice has focused on the development of climate-smart rice varieties, models, and practices to overcome the direct effects of climate change, such as increased temperatures, droughts, and floods – in order to boost rice productivity and ensure sustainable rice production in Africa.

 

Climate-smart varieties

Rice varieties robust enough to grow well in different rice ecologies and withstand drought or flooding spells would greatly reduce the risk for rice producers.

• ARICA varieties: The Advanced Rice Variety for Africa (ARICA) is a new generation of high-performing varieties. They are developed for either upland, or irrigated lowland, or rainfed lowland ecosystems. Besides high yield potential, acceptable grain quality, and resistances to major diseases such as blast, bacterial leaf blight (BLB) and rice yellow mottle virus (RYMV), tolerances to abiotic stresses – such as drought for upland rice, drought and floods for rainfed lowland rice – are introgressed into new varieties.

• Stress-tolerant and high-yielding varieties: Breeding for abiotic-stress tolerance is an important option to help farmers produce more food despite climate change. Some of the stresses such as flooding, drought, cold and soil salinity, are forecast to become more frequent and intense with climate change. Between 2014 and 2019, thanks to the ‘Stress-Tolerant Rice for Africa and South Asia’ (STRASA) project, 82 high-yielding and stress-tolerant varieties were released in 16 African countries. QTLs associated with tolerance to drought, anaerobic germination, salinity, iron toxicity and cold were identified.

• Development of flood-tolerant varieties: Near-isogenic lines carrying the Sub1 (submergence tolerance) gene were developed using marker-assisted selection from the popular ‘mega-varieties’ WITA 4 and NERICA-L 19. These were released in Nigeria in 2017, as FARO 66 and FARO 67, respectively. These two varieties produce 6–29% higher yield under non-submergence conditions than their recurrent parents, but if submerged for a week or two, they can produce 10–80 times more yield than their recurrent parents.

• Development of salt-tolerant rice varieties: Salinity problems are expected to become more widespread world-wide because of climate change. Research carried out by AfricaRice involved the introgression of the Saltol gene, which confers salt tolerance in rice seedlings, into a popular cultivar Rassi. Some 16 Saltol-introgressed lines (ILs) were identified that had 3–26% yield loss under salt stress compared to unstressed controls. Guinea has released three of these Saltol-ILs (named Mamya, Tonsekerin and Toureya) for salt-affected lowland rice cropping.

• Breeding for heat tolerance: With global heating, high temperature is an increasingly key abiotic stress especially in the Sahel.  Oryza glaberrima is considered heat tolerant during the reproductive stage as it flowers early in the morning and thereby escapes heat stress. AfricaRice has identified a set of 15 O. glaberrima accessions, which constitute promising donors for use in rice breeding for heat tolerance.

• Breeding for cold tolerance: In Eastern and Southern African (ESA) highland zones, rice production faces cold stress. Similarly, in the Sahel region, seasonal cold affects the double cropping in irrigated zones. To address these challenges, 15 cold-tolerant varieties for ESA have been developed, evaluated and disseminated in the low temperature stress-affected regions through the Africa-ide Rice Breeding Task Force mechanism.

• Rice disease and climate change: As part of the project ‘Mitigating the impact of climate change on rice disease resistance in East Africa’ (MICCORDEA), the distribution and severity of two rice diseases, bacterial blight and blast, in Rwanda, Tanzania and Uganda were mapped to establish baseline data to measure changes in disease patterns under the influence of climate change and to discover resistance genes (tools for climate proofing) to better target rice breeding efforts.

 

Climate Models/Maps

• ORYZA2000 crop simulation model for Africa: ORYZA_S developed by AfricaRice in the 1990s allowed regional analysis of climatic risk to irrigated rice cropping in the Sahel and zonation of regions with potential for double cropping. An improved version, ORZYA2000, was released in 2001 by IRRI. A new adapted subversion of ORYZA2000 has been developed by AfricaRice that offers a powerful analytic tool for climate change impact assessment and cropping calendar optimization in Africa.

https://models.pps.wur.nl/oryza2000-rice-crop-growth-simulation-model

https://www.sciencedirect.com/science/article/pii/S2211912415000036

https://journals.plos.org/plosone/article?id=10.1371/journal.pone.0118114

• Simple model for simulating heat induced sterility in rice as a function of flowering time and transpirational cooling:  New simple model for predicting transpirational cooling as a function of relative humidity and air temperature was developed by AfricaRice for simulating heat induced sterility in rice.

https://models.pps.wur.nl/simple-model-simulating-heat-induced-sterility-rice-function-flowering-time-and-transpirational

https://www.sciencedirect.com/science/article/pii/S0378429013003912

• Cropping Calendar Construction (CCC): The CCC is an Excel-based tool developed by AfricaRice, which can help researchers and extension agents investigate intensification options and optimize cropping calendar for irrigated rice-based systems.

https://models.pps.wur.nl/cropping-calendar-construction-ccc-model

• Drought prediction model: AfricaRice has evaluated the predictors of drought in inland-valley rice-based production systems in Burkina Faso, Mali and Nigeria and the factors affecting farmers’ mitigation measures. Among 21 candidate drought-predictors, average annual ‘standardized precipitation evapotranspiration index’ (SPEI), a drought index that includes a comprehensive water balance) and duration of groundwater availability were best correlated with drought occurrence in inland-valley rice-based systems.

https://www.mdpi.com/2071-1050/11/1/79

• Mapping abiotic stress of rice: AfricaRice has developed maps to aid targeting of abiotic-stress-tolerant rice varieties. Maps for four abiotic stresses (drought, cold, iron toxicity and salinity) have been prepared. All the related maps and tables generated are publicly available. 

https://dataverse.harvard.edu/dataverse/AfricaRice?q=Abiotic+stress+maps+for+rice+(STRASA)

• The Global Yield Gap and Water Productivity Atlas (GYGA): It provides robust estimates of untapped crop production potential on existing farmland based on current climate and available soil and water resources. AfricaRice contributed to estimation of yield gap for rice in Burkina Faso, Côte D'ivoire, Ghana, Madagascar, Mali, Niger, Nigeria, Rwanda, Senegal, Tanzania, Uganda, and Zambia.

http://www.yieldgap.org/

• RiceAtlas: it is a spatial database of global rice calendars and production. It consists of data on rice planting and harvesting dates by growing season and estimates of monthly production for all rice-producing countries. AfricaRice and its national partners provide with expert knowledge of those information in Africa.

https://www.nature.com/articles/sdata201774

 

Climate-smart agronomic practices and tools

• Smart-valleys: With increased risk of drought in large parts of Africa because of climate change, well-managed lowlands can contribute to food security through enhanced productivity of rice-based systems. ‘Smart-valleys’ is a climate-smart, low-cost, participatory approach to develop lowlands for rice-based systems. On average, adoption of Smart-valleys approach enabled producers in Benin and Togo to increase yields by 0.92 t/ha (0.88 t/ha for women) and net income by US$267/ha (US$198/ha for women). The approach has been successfully validated in Burkina Faso, Liberia and Sierra Leone.

https://link.springer.com/chapter/10.1007/978-3-319-77878-5_11

• RiceAdvice mobile app: AfricaRice has developed the RiceAdvice app for providing farmers with personalized advice to farmers on rice management practices in Africa via smartphones and tablets. RiceAdvice has been piloted in 13 African countries and has reached more than 60,000 rice farmers. Potential beneficiaries are expected to be at least 3 million households in Africa. The use of this tool increases yield by 0.5-1 t/ha and profitability by US$200 USD per ha per growing season.

• Alternate wetting and drying (AWD): Based on water-saving experiments in irrigated rice schemes in the Senegal River valley, AfricaRice has found that with AWD, it is possible to attain major savings of irrigation water with little loss of yield in a Sahelian environment: irrigation water savings of 22–39% are possible for rice with no or little yield loss, while maintaining high water productivity. The technology is now under testing in Burkina Faso and Côte d'Ivoire.

https://www.mdpi.com/2073-4441/10/6/711

• Sustainable Rice Platform (SRP) Standard and Performance Indicators: AfricaRice is working with the Sustainable Rice Platform (SRP), which has developed the world’s first rice sustainability standard and impact indicators, to encourage rice smallholders to adopt climate-smart, sustainable best practices. AfricaRice contributed to revision of those tools, which was released in Jan 2019.

http://www.sustainablerice.org/

 

Eco-friendly postharvest technology

• Rice husk gasifier: Innovative uses of husks and straw instead of burning will provide local business opportunities and extra income sources for farmers, and simultaneously mitigate climate change. An enhanced GEM model that includes an eco-friendly stove has shown 100% savings on fuel wood by using rice husk, which is a free and abundant fuel in rice-producing areas in Africa