Rice production threatened by coupled stresses of climate and soil arsenic

E Marie Muehe,Carolin F Kerl,Britta Planer-Friedrich,Scott Fendorf,Tianmei Wang

doi:10.1038/s41467-019-12946-4

E Marie Muehe, Carolin F Kerl + Show 3 more

Open Access

https://doi.org/10.1038/s41467-019-12946-4

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Abstract

Projections of global rice yields account for climate change. They do not, however, consider the coupled stresses of impending climate change and arsenic in paddy soils. Here, we show in a greenhouse study that future conditions cause a greater proportion of pore-water arsenite, the more toxic form of arsenic, in the rhizosphere of Californian Oryza sativa L. variety M206, grown on Californian paddy soil. As a result, grain yields decrease by 39% compared to yields at today’s arsenic soil concentrations. In addition, future climatic conditions cause a nearly twofold increase of grain inorganic arsenic concentrations. Our findings indicate that climate-induced changes in soil arsenic behaviour and plant response will lead to currently unforeseen losses in rice grain productivity and quality. Pursuing rice varieties and crop management practices that alleviate the coupled stresses of soil arsenic and change in climatic factors are needed to overcome the currently impending food crisis.

Highlights

Projections of global rice yields account for climate change
According to the International Panel on Climate Change (IPCC) report (5th Assessment Report, Representative Concentration Pathway RCP 8.5)[43], a 2014 projection indicated that it is very likely that atmospheric CO2 concentrations would reach 570 ppmv compared with the present level and that temperature would increase 1.5 to 2 °C by the end of this century
The combined impacts of changing climatic conditions and increased soil arsenic resulted in a 42% decrease in yield to 6.6 ± 0.5 g of grain plant−1 with 81% grain filling

Summary

Introduction

Projections of global rice yields account for climate change. They do not, consider the coupled stresses of impending climate change and arsenic in paddy soils. Current empirically derived and modelled projections on rice production account for climate change as a constraining factor to yields[2,3,4,5,6,7] They do not consider the coupled stresses of climate change and the presence of arsenic, a plant and human toxin, in paddy soils[6,7,8,9,10,11]. To a lesser extent increased atmospheric CO2, will affect soil biogeochemical processes by altering microbial community dynamics and activity and geochemical reactions that include contaminant/nutrient adsorption/desorption and mineral dissolution/precipitation[18,39,40,41] How such altered biogeochemical processes affect soil arsenic and the resulting impacts on rice production, remain unresolved. We used a greenhouse in greenhouse pot study design (see the Methods section, Supplementary Fig. 1) allowing for a tight control of temperature and atmospheric CO2 concentrations, and to more determine differences in soil arsenic dynamics and plant behaviour

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