环境地球化学国家重点实验室知识库

Rice (Oryza sativa L.) paddies are increasingly threatened by cadmium (Cd) pollution, and potentially serve as CH₄ emitters to the atmosphere. Remediation agents widely mitigate Cd pollution in paddy soil, however, we know little about their regulations on CH₄ emission. Here, via adding biochar (B), sulfhydryl-modified palygorskite (SMP), and selenium foliar fertilizer (SFF), we conducted a pot experiment to investigate soil and rice Cd contents together with in-situ CH₄ fluxes. Compared to CK, the addition of SMP, SFF, and B-SMP reduced Cd in brown rice by 25% to 50%, 25%, and 50% to 75%, respectively. Agents 7% B, 7% B-0.01% SMP, and SFF reduced CH₄ emissions by 8.46%, 5.30%, and 4.11%, respectively. CH₄ emission increased gradually along the growing season, with the cumulative CH₄ fluxes ranging between 338.82 and 619.13 kg hm⁻². Our results highlight that mixed 7% B-0.01% SMP and SFF showed collaborative effects on Cd remediation and CH₄ emission. This study reveals the feasibility of reducing Cd pollution and CH₄ emission in karst rice paddies, which hopes to supplement the knowledge of collaborative controls on soil remediation and carbon emission.