Alternative sowing dates as a mitigation measure to reduce climate change impacts on soybean yields in southern Brazil

Abstract

ABSTRACT:The climate and its variability is the main risk factor for the success of soybean crop in southern Brazil. Such aspect becomes even more important under the future climate scenarios, in which global warming is expected. Based on that, the objectives of this study were to identify the impacts of raising temperatures on soybean yields in southern Brazil and how management strategies represented by changing sowing dates could be able to mitigate them. The soybean yields for the present and future scenarios were estimated by the crop simulation model CROPGRO-Soybean calibrated for southern Brazil. The simulations were done for 13 locations distributed in the states of Paraná, Santa Catarina and Rio Grande do Sul, considering climatic series of 31 years. The future climate scenarios were built based on downscaling temperature changes from ETA and PRECIS models for the periods: 2013-2043 (D25) and 2041-2071 (D55), without considering the increase in the atmospheric CO 2 concentration. The soybean potential (Y p ) and attainable (Y a ) yields and their relationship (Y a /Y p ) were estimated for all scenarios and used to determine the climatic risk for the crop. In order to investigate how to mitigate the global warming impacts on soybean yields, different sowing dates, two earlier and two later than the present recommendation, were simulated in the crop model and resulting yields were compared. In general, raising temperature will lead soybean crop in southern Brazil to lower yields, for both Y p and Y a , with higher impact on Y a , independently of the climate model used. Also, the climatic risk for the crop will increase in the future climates scenarios. The strategy of changing the sowing date showed to be feasible to reduce the impacts of raising temperatures on soybean yields, but only when it is delayed in relation to the sowing period presently recommended for this crop in the region.

Integrating Plant Science and Crop Modeling: Assessment of the Impact of Climate Change on Soybean and Maize Production

“…Of the literature used in this analysis, six studies failed to consider the direct effect of high [CO 2 ] on soybeans. All studies projected yield losses for soybean, which might be mitigated by agricultural management adaptations such as changing the planting date (do Rio et al 2016), change of cultivars (Battisti et al 2017) or introducing double-cropping systems (Lant et al 2016). The global study of Tatsumi et al (2011) projected yield decrease for all the major soybean producing areas.…”

Soybean yield in future climate scenarios for the state of Rio Grande do Sul, Brazil

“…2017 DOI: 10.1590/S0100-204X2017000600002 lowest-available water content for the plants which is, for instance, 20-40% lowest in the RCP4.5-CMIP5 scenario than in SRES A1B-CMIP3, at 0-15 cm soil depth, in Passo Fundo region, in the northeastern of the state. Rio et al (2016) also found a yield decrease for the 2041-2071 scenario, for the South of Brazil, with the Cropgro-Soybean forced by the SRES A2 and B2 scenarios, without considering the effect of elevated CO 2 . In the RCP4.5-CMIP5 scenario, there are periods without rain during the critical stages of soybean development, R1 and R3, that caused yield reduction during the period of 1980-2099, which agrees with Dogan et al (2007), who showed that the highest soybean yield losses occur when the irrigation cease in the R3, R5, and R6 stages.…”

“…Studies on the impact of climate change on soybean in Brazil, particularly in the state of Rio Grande do Sul, have been conducted using crop models, such as Soygro and Cropgro-Soybean, forced by synthetic climate scenarios, and by the SRES A1 and A2 scenarios of CMIP3, considering few sowing dates (Siqueira et al, 1994(Siqueira et al, , 2000Streck & Alberto, 2006;Justino et al, 2013;Rio et al, 2016). With the update of CMIP5 scenarios (Stocker et al, 2013), new soybean cultivars released annually, and the development of new crop simulation models as SoySim (Setiyono et al, 2010), studies on the impact of future scenarios on soybean in Rio Grande do Sul should be continued, taking into consideration these new tools and technologies.…”

Percepções de universitários sobre as mudanças climáticas e seus impactos: estudo de caso no Distrito Federal

“…Relacionado aos alimentos, o setor agropecuário se apresenta como altamente dependente das condições ambientais e climáticas, sendo o risco climático e os modelos de previsão do Intergovernmental Panel on Climate Change (IPCC) incorporados como instrumentos da política pública de gestão de riscos na agricultura desde 1996 (ASSUNÇÃO; CHEIN, 2016). Alguns impactos previstos são a diminuição da produção de leites e dos cultivos de café, feijão, milho e soja (RIO et al, 2016;HEINEMANN et al, 2017). Esses resultados estão refletidos na percepção de que as mudanças climáticas influenciam de forma negativa o setor de alimentos, podendo também estar relacionada à crise de alimentos de 2007de -2008de (McMICHAEL, 2009) e ao aumento dos preços de alguns itens alimentares nos últimos anos, como, por exemplo, o feijão em 2016.…”