钝化修复对不同水稻品种镉累积效应及土壤特性的影响

为了探讨坡缕石钝化修复下不同水稻品种(T优272和丰优9号)吸收累积Cd差异,采用盆栽试验,研究了酸性Cd污染稻田土(PL1、PL2和PL3处理)对2种水稻品种重金属Cd累积效应,以及对土壤酶活性、氮磷有效性的影响。结果表明,种植的常规水稻品种T优272稻谷干物质量比低Cd吸收品种丰优9号高7.91%。坡缕石钝化修复下,T优272与丰优9号稻谷干物质量无显著差异,但土壤p H值分别较CK增加了0.33~0.46和0.40~0.53。与CK相比,PL1F、PL2F和PL3F处理土壤有效态Cd质量分数最大降低13.59%,稻米Cd质量分数降幅达20.51%~51.28%,其中PL3F处理的稻米Cd质量分数为0.19 mg/kg,低于食品安全国家标准限量值(0.20 mg/kg);PL1T、PL2T和PL3T处理土壤有效态Cd质量分数最大降低25.08%,糙米Cd质量分数最大降低37.50%,其中PL3T处理糙米Cd质量分数为0.35 mg/kg。土壤酶活性随着坡缕石添加量的增加而逐渐升高,而且种植T优272品种的土壤酶活性总体上高于丰优9号。随着坡缕石添加量的增加,钝化修复各处理间土壤碱解氮质量分数无显著差异,但土壤有效磷质量分数呈逐渐降低趋势;与CK相比,种植丰优9号和T优272品种的土壤有效磷质量分数分别降低了7.08%~18.08%和9.02%~19.59%。研究结果可为重金属Cd污染酸性水稻田土壤坡缕石钝化与低Cd吸收水稻品种联合修复提供一定的科学依据。

Effects of Immobilization Remediation of Cadmium Contaminated Paddy Soil on Cadmium Accumulation and Soil Properties in Different Rice Varieties

In order to study the difference of the accumulation of Cd in different rice varieties under palygorskite immobilization remediation of cadmium contaminated paddy soil,pot experiments were conducted to investigate the effect of palygorskite immobilization remediation of cadmium contaminated paddy soil on Cd accumulation in different rice varieties,and soil enzyme activity and nitrogen and phosphorus availability.The results showed that T You 272 rice biomass was 7.91%higher than the Feng You 9 rice,but there was no statistically significant difference.Under palygorskite immobilization remediation,the soil pH values of planting T You 272 and Feng You 9 were increased by 0.33~0.46 and 0.40~0.53,respectively.Under PL1F,PL2F and PL3F treatment,the maximum decrease of soil available Cd was 13 .59%,and the Cd of brown rice was decreased by 20.51%~50.28%,and the Cd content of brown rice under PL3F treatment was 0.19 mg/kg.In addition,the maximum de-crease of soil available Cd was 25.08%,and the maximum reduced of brown rice Cd was 37.50% under PL1T, PL2T and PL3 T treatment,and the Cd content of brown rice under PL3 T treatment was 0.35 mg/kg.The soil en-zyme activity was increased gradually with the increase of the amount of palygorskite added,and the soil enzyme activity of T You 272 was higher than that of Feng You 9.With the increase of the amount of palygorskite added, the soil alkali solution nitrogen had no significant difference in different treatments,but the content of available phosphorus in soil decreased gradually.Compared with CK,the contents of soil available phosphorus under PLF and PLT treatments could be decreased by 7.08%~18.08%and 9.02%~19.59%,respectively.The research re-sults could provide the scientific basis for immobilization remediation of cadmium contaminated paddy soil com-bined with low Cd accumulation of rice varieties.