Water Management Impacts on Chromium Behavior and Uptake by Rice in Paddy Soil with High Geological Background Values
Zeting Guan,
Ran Wei,
Ting Liu,
Jingjing Li,
Ming Ao,
Shengsheng Sun,
Tenghaobo Deng,
Shizhong Wang,
Yetao Tang,
Qingqi Lin,
Zhuobiao Ni,
Rongliang Qiu
Affiliations
Zeting Guan
Guangdong Laboratory for Lingnan Modern Agriculture, Guangdong Provincial Key Laboratory of Agricultural & Rural Pollution Abatement and Environmental Safety, College of Natural Resources and Environment, South China Agricultural University, Guangzhou 510642, China
Ran Wei
Guangdong Laboratory for Lingnan Modern Agriculture, Guangdong Provincial Key Laboratory of Agricultural & Rural Pollution Abatement and Environmental Safety, College of Natural Resources and Environment, South China Agricultural University, Guangzhou 510642, China
Ting Liu
Guangdong Laboratory for Lingnan Modern Agriculture, Guangdong Provincial Key Laboratory of Agricultural & Rural Pollution Abatement and Environmental Safety, College of Natural Resources and Environment, South China Agricultural University, Guangzhou 510642, China
Jingjing Li
Guangdong Laboratory for Lingnan Modern Agriculture, Guangdong Provincial Key Laboratory of Agricultural & Rural Pollution Abatement and Environmental Safety, College of Natural Resources and Environment, South China Agricultural University, Guangzhou 510642, China
Ming Ao
Guangdong Provincial Key Laboratory of Environmental Pollution Control and Remediation, School of Environmental Science and Engineering, Sun Yat-sen University, Guangzhou 510006, China
Shengsheng Sun
Guangdong Provincial Key Laboratory of Environmental Pollution Control and Remediation, School of Environmental Science and Engineering, Sun Yat-sen University, Guangzhou 510006, China
Tenghaobo Deng
Institute of Quality Standard and Monitoring Technology for Agro-Products of Guangdong Academy of Agricultural Sciences, Guangzhou 510640, China
Shizhong Wang
Guangdong Provincial Key Laboratory of Environmental Pollution Control and Remediation, School of Environmental Science and Engineering, Sun Yat-sen University, Guangzhou 510006, China
Yetao Tang
Guangdong Provincial Key Laboratory of Environmental Pollution Control and Remediation, School of Environmental Science and Engineering, Sun Yat-sen University, Guangzhou 510006, China
Qingqi Lin
Guangdong Laboratory for Lingnan Modern Agriculture, Guangdong Provincial Key Laboratory of Agricultural & Rural Pollution Abatement and Environmental Safety, College of Natural Resources and Environment, South China Agricultural University, Guangzhou 510642, China
Zhuobiao Ni
Guangdong Laboratory for Lingnan Modern Agriculture, Guangdong Provincial Key Laboratory of Agricultural & Rural Pollution Abatement and Environmental Safety, College of Natural Resources and Environment, South China Agricultural University, Guangzhou 510642, China
Rongliang Qiu
Guangdong Laboratory for Lingnan Modern Agriculture, Guangdong Provincial Key Laboratory of Agricultural & Rural Pollution Abatement and Environmental Safety, College of Natural Resources and Environment, South China Agricultural University, Guangzhou 510642, China
Chromium (Cr) is an expression toxic metal and is seriously released into the soil environment due to its extensive use and mining. Basalt is an important Cr reservoir in the terrestrial environment. Cr in paddy soil can be enriched by chemical weathering. Therefore, basalt-derived paddy soils contain extremely high concentrations of Cr and can enter the human body through the food chain. However, the water management conditions’ effect on the transformation of Cr in basalt-derived paddy soil with high geological background values was less recognized. In this study, a pot experiment was conducted to investigate the effects of different water management treatments on the migration and transformation of Cr in a soil–rice system at different rice growth stages. Two water management treatments of continuous flooding (CF) and alternative wet and dry (AWD) and four different rice growth stages were set up. The results showed that AWD treatment significantly reduced the biomass of rice and promoted the absorption of Cr in rice plants. During the four growth periods, the root, stem and leaf of rice increased from 11.24–16.11 mg kg−1, 0.66–1.56 mg kg−1 and 0.48–2.29 mg kg−1 to 12.43–22.60 mg kg−1, 0.98–3.31 mg kg−1 and 0.58–2.86 mg kg−1, respectively. The Cr concentration in roots, stems and leaves of AWD treatment was 40%, 89% and 25% higher than CF treatment in the filling stage, respectively. The AWD treatment also facilitated the potential bioactive fractions conversion to the bioavailable fraction, compared with the CF treatment. In addition, the enrichment of iron-reducing bacteria and sulfate-reducing bacteria with AWD treatment also provided electron iron for the mobilization of Cr, thus affecting the migration and transformation of Cr in the soil. We speculated that the reason for this phenomenon may be the bioavailability of Cr was affected by the biogeochemical cycle of iron under the influence of alternating redox. This indicates that AWD treatment may bring certain environmental risks in contaminated paddy soil with high geological background, and it is necessary to be aware of this risk when using water-saving irrigation to plant rice.
