ALBERT

Description: SUMMARYBrazil is one of the most important soybean producers in the world. Soybean is a very important crop for the country as it is used for several purposes, from food to biodiesel production. The levels of soybean yield in the different growing regions of the country vary substantially, which results in yield gaps of considerable magnitude. The present study aimed to investigate the soybean yield gaps in Brazil, their magnitude and causes, as well as possible solutions for a more sustainable production. The concepts of yield gaps were reviewed and their values for the soybean crop determined in 15 locations across Brazil. Yield gaps were determined using potential and attainable yields, estimated by a crop simulation model for the main maturity groups of each region, as well as the average actual famers’ yield, obtained from national surveys provided by the Brazilian Government for a period of 32 years (1980–2011). The results showed that the main part of the yield gap was caused by water deficit, followed by sub-optimal crop management. The highest yield gaps caused by water deficit were observed mainly in the south of Brazil, with gaps higher than 1600 kg/ha, whereas the lowest were observed in Tapurah, Jataí, Santana do Araguaia and Uberaba, between 500 and 1050 kg/ha. The yield gaps caused by crop management were mainly concentrated in South-central Brazil. In the soybean locations in the mid-west, north and north-east regions, the yield gap caused by crop management was 2000 kg/ha. For reducing the present soybean yield gaps observed in Brazil, several solutions should be adopted by growers, which can be summarized as irrigation, crop rotation and precision agriculture. Improved dissemination of agricultural knowledge and the use of crop simulation models as a tool for improving crop management could further contribute to reduce the Brazilian soybean yield gap.

Description: Madagascar has a high socio-economic dependency on agriculture, a sector which is strongly influenced by weather-related factors and increasingly challenged by the impacts of climate change. Currently, only limited information on climate risks and its impacts is available for the country’s agricultural sector. This study aims to provide a comprehensive climate risk analysis including a thorough evaluation of two potential adaptation strategies that can guide local decision-makers on adaptation planning and implementation in Madagascar. The impact assessment consists of several steps, including climate projections based on three emissions scenarios (SSP1-RCP2.6, SSP3- RCP7.0 and SSP5-RCP8.5 scenario), modelling and comparison of future suitability and yield of three widely used crops (coffee, vanilla, pepper) and an assessment of yield changes in peanut production under future climate conditions. Further, the study outlines gendered challenges and support requirements in national adaptation planning. The simulation results show that Robusta coffee is less sensitive to heat compared to Arabica coffee. The suitable area for Robusta coffee remains almost stable under changing climate conditions, while the suitability of Arabica coffee is projected decrease by 7 % on a national level. Simulation results indicate a slight increase in suitability for vanilla production, particularly in the main growing region Sava, but also in Atsimo Atsinanana, thus safeguarding an important source of income for local farmers and guaranteeing the sustainability of Madagascar´s most valuable export product. Furthermore, climate change is projected to have a rather low impact on the agro-climatic suitability of pepper production. When averaged across Madagascar, the decrease in suitability is less than 1 %, however, there are some noteworthy differences across regions and scenarios. The results for the process-based peanut modelling show that rising temperature and reduced rainfall amounts are likely to decrease peanut yields across Madagascar. However, elevated atmospheric CO2 is projected to offset these negative impacts. The study furthermore evaluated the efficiency of two adaptation strategies, namely the use of locally adapted crop varieties and flexible planting dates. The simulation results suggest that the traditional cultivar Kanety is more suited in future climate change scenarios since yields for Kanety are generally higher than those of the improved variety Fleur 11. Interestingly, opting for flexible planting dates as opposed to a fixed planting date does not result in enhanced yields. This result underlines the importance of regional crop calendars to determine optimal sowing dates. The findings of this study can help to inform national and local adaptation and agricultural development planning and investments in order to strengthen the resilience of the agricultural sector and especially of smallholder farmers against a changing climate in Madagascar.