Effects and mechanisms of different exogenous organic matters on selenium and cadmium uptake by rice in natural selenium-cadmium-rich soil
Year: 2024
Type: article
Abstract: Many natural selenium (Se)-rich rice plants are being polluted by cadmium (Cd). In this study, for reducing Cd concentrations in rice grains while maintaining Se concentrations, the effects of different exogenous organic matters (OMs), such as humic acid (HA), cow manure (CM), and vermicompost (VC), on Se and Cd uptake in rice growing in natural Se-Cd-rich paddy soils were investigated by pot experiments. The Se and Cd concentrations in the soil solution, their species in the soil, and their concentrations and translocations in rice tissues were determined. Results showed that different exogenous OMs exhibited distinct percentage changes in Se and Cd levels in rice grains with amplitudes of −19.42 % and −56.90 % (significant, p < 0.05) in the HA treatments, +10.79 % and −1.72 % in the CM treatments, and +15.83 % and −15.52 % in the VC treatments, respectively. Correlation analysis showed that the concentrations of Se and Cd in rice grains might be primarily influenced by their concentrations in the soil solution, rather than the Se/Cd molar ratios in the soil solution or their translocations in rice tissues. HA decreased Se and Cd bioavailability in soil by increasing HA-bound Se and residual Cd, respectively. Meanwhile, HA increased soil solution pH, which was negative for Cd bioavailability but positive for Se bioavailability. This additive effect made HA lowered Cd concentration more than Se concentration in both soil solution and grain. CM and VC did not have this additive effect and thus have limited effects on grain Se and Cd concentrations. In addition, according to grain Se and Cd concentrations, to prioritize reducing Cd in rice, use HA; to prioritize increasing Se in rice, use VC. This study enhances the understanding of Se and Cd uptake mechanisms in rice with the applications of various OMs and offers potential remediation methods for Se-Cd-rich paddy soils.
Source: Heliyon
Authors: Hongyu Zhang, Shuyun Xie, Xiaoping Du, Zhengyu Bao, Feng Xu, Salah Fadlallah Awadelseid, Oraphan Yaisamut
Language: English
Topic: Heavy metals in environment
Subfield: Pollution
Field: Environmental Science
Domain: Physical Sciences
SDG: Zero hunger
Open Access status: gold
Estimated APC paid: $2,100
Funders: National Natural Science Foundation of China, China University of Geosciences, Wuhan, Hebei GEO University, Ministry of Agriculture and Rural Affairs of the People's Republic of China, China University of Geosciences, Natural Science Basic Research Program of Shaanxi Province, National-Local Joint Engineering Laboratory of Se-enriched Food Development
OpenAlex ID: W4402395880