RACe · The impact of climate change on the uptake of arsenic into rice

The impact of climate change on the uptake of arsenic into rice

Rice is the staple food worldwide. Unfortunately, global rice yield is already falling behind population growth. With more than half of the world’s population consuming rice daily, it is crucial to ensure future rice productivity and quality for a growing population. Most crucial constraints to future rice production in Asia and the US are climate change and the contaminant arsenic that is enriching in paddy soils. According to the highest emission scenario for greenhouse gases presented in the 5th assessment report of the IPCC, global annual temperatures could rise by more than 5°C by the year 2100. Thus, the objective for the RACe-MSC-action was to investigate whether a changing climate combined with rising arsenic levels in the soil affect the grain yield and quality of rice. To better understand the uptake of arsenic into the plant, changes in soil geochemistry and arsenic dynamics in the bulk soil compared to the rhizosphere soil were assessed using classic geochemical approaches combined with high resolution, synchrotron-based mineralogical analysis. Furthermore, omics-based sequencing of the soil microbial community in proximity to rice roots serve to mechanistically explain the observed changes in soil geochemistry. Overall, climate-induced changes of the fate of arsenic in the soil and the response of the plant will lead to unpredictable losses in rice grain productivity and quality at this point. Global models of rice production need to include contaminant dynamics in order to not overestimate rice production in the future. The main results of the project were: - The availability of arsenic in the soil increased due to future climatic conditions. - Iron(III) and arsenate(V) reducing microbial communities are responsible for shifts in arsenic mobility in the soil. - M206 grain yields decrease by 42% due to combined climate and soil arsenic stress compared to yields at today’s climate and arsenic soil concentrations. - Future climatic conditions cause a nearly twofold increase of grain inorganic arsenic concentrations compared to today's climatic conditions. - Soil arsenic is the stronger determinant of rice yield compared to climatic condition. - A shift to future climatic conditions adversely affect grain arsenic levels even at low soil arsenic concentrations. - Temperature increases soil arsenic bioavailability, elevated CO2 as well, though combined they increase arsenic bioavailability in between. - Temperature decreases grain yields, elevated CO2 increases grain yield, jointly they decrease grain yield.

Текст от CORDIS, на английски · Данни: CORDIS, © Европейски съюз