选取海泡石、石灰、铁改性木本泥炭和弱碱性生物有机肥等4种钝化剂为材料，研究其对镉（Cd）污染稻田土壤原位修复效果及土壤酶活性的影响。结果表明，施用4种钝化剂均能提升土壤pH和水稻产量，降低土壤中Cd生物有效性和糙米Cd含量，且糙米Cd含量低于国家食品安全标准限值（Cd≤0.2 mg/kg）。施用1 500 kg/hm²弱碱性生物有机肥的处理对土壤pH提升效果最好，从6.07提升至7.00，增幅为13.2%；施用2 500 kg/hm²铁改性木本泥炭的处理，土壤有效态Cd和糙米Cd含量降幅最大，分别从0.538 mg/kg和0.260 mg/kg下降至0.232 mg/kg和0.076 mg/kg，分别下降了56.8%和70.8%。施用1 500 kg/hm²弱碱性生物有机肥的处理增产水稻效果最好，增幅为6.4%。施用4种钝化剂后，土壤中蔗糖酶、脲酶和过氧化氢酶活性均有不同程度提升。其中，施用1 200 kg/hm²生石灰处理对土壤中蔗糖酶活性提升效果最好；施用2 500 kg/hm²铁改性木本泥炭处理对土壤中脲酶活性提升效果最明显；施用1 500 kg/hm²弱碱性生物有机肥处理对土壤中过氧化氢酶活性提升效果最好。相关分析表明，糙米Cd含量与土壤蔗糖酶、脲酶及过氧化氢酶活性均呈负相关，说明施用这4种钝化剂均可以降低糙米Cd含量。综合考虑4种钝化材料对土壤有效态Cd、糙米Cd含量及土壤酶活性的影响效果，用铁改性木本泥炭修复Cd污染土壤较为适宜。

The effects of four passivators, including sepiolite, lime, iron-modified woody peat and weakly alkaline bio-organic fertilizer, on in situ remediation of cadmium （Cd）-contaminated paddy soil and soil enzyme activities were studied. The results showed that the four passivators could improve soil pH and rice yield, reduce Cd bioavailability in soil and Cd content in brown rice, and the Cd content in brown rice was lower than the national food safety standard limit （Cd≤0.2 mg/kg）. The treatment of applying 1 500 kg/hm² weakly alkaline bio-organic fertilizer had the best effect on increasing soil pH, from 6.07 to 7.00, an increase of 13.2%. The treatment with 2 500 kg/hm² iron-modified woody peat had the largest decrease in soil available Cd and brown rice Cd content, from 0.538 mg/kg to 0.232 mg/kg and 0.260 mg/kg to 0.076 mg/kg, respectively, with a decrease of 56.8% and 70.8%. The treatment of 1 500 kg/hm² weak alkaline bio-organic fertilizer had the best effect of increasing rice yield, with an increase of 6.4%. The activities of invertase, urease and catalase in soil were increased to varying degrees after the application of the four passivators. Among them, the treatment of applying 1 200 kg/hm² of quicklime had the best effect on improving the activity of invertase in soil, the treatment of applying 2 500 kg/hm² of iron-modified woody peat had the most obvious effect of improving the activity of urease in soil, the treatment of 1 500 kg/hm² weak alkaline bio-organic fertilizer had the best effect on improving the activity of catalase in soil. Correlation analysis showed that the Cd content in brown rice was negatively correlated with the activities of soil invertase, urease and catalase, indicating that the application of these four passivators could reduce the Cd content in brown rice. Based on the effects of four passivators on soil available Cd, Cd content in brown rice and soil enzyme activity, iron-modified woody peat is more suitable for remediation of cadmium-contaminated soil.