组配改良剂对土壤和水稻糙米重金属积累的影响

目的]研究组配改良剂对Cd污染稻田的修复效果。方法]在湖南省长沙县春华镇污染稻田进行了组配改良剂的田间试验,设4个处理,分别为T_1:未添加改良剂(CK);T_2:生石灰(0.1%)翻耕整地时混施;T_3:TH01(0.4%)+生石灰(0.1%)翻耕整地时混施;T_4:翻耕整地时混施TH02(0.4%),分蘖前期撒施生石灰(0.1%)。研究添加改良剂对水稻产量、重金属含量和土壤重金属含量的影响。结果]4个处理间水稻分蘖情况、子粒生物量差异不明显;T_3处理子粒的Cd含量最低,且T_3、T_4处理水稻子粒的Cd含量分别降低了45.22%、38.14%,而与T_2处理相比,T_3、T_4处理水稻子粒Cd含量分别降低36.16%、27.91%;不同生长期水稻茎叶、根Cd含量与土壤醋酸铵Cd含量呈线性相关关系。结论]可在孕穗期后水稻进入灌浆期前采取农艺措施或添加稳定剂降低稻田土壤醋酸铵Cd含量,从而降低水稻子粒Cd含量。

Effects of Improved Agent on Heavy Metal Accumulation in Soil and Brown Rice

Objective] The aim was to study remediation effect of improved agent on Cd contaminated paddy soils .Method] A field experiment of improved agent was conducted on a contaminated paddy soil in Chunhua Town ,Changsha County,Hunan Province.Setting up 4 treatments,in-cluding T1 :without improved agent(CK); T2:quick lime (0.1%),fertilizing in soil preparation process; T3:TH01 (0.4%) + quick lime (0.1%),fertilizing in soil preparation process; T4:TH02(0.4%),fertilizing in soil preparation process,quick lime(0.1%) applying at early tillering stage.Effects of adding improved agent on rice yield,heavy metal content and soil heavy metal content were studied.Result] Rice tiller and grain biomass had no significant difference among 4 treatments; Cd content was lowest in T 3 treatment,Cd content reduced 45.22% and 38.14% in T3 and T4 ,compared with T2 ,Cd content reduced 36.16% and 27.91% in T3 and T4 .In different growth period,stems,leaves and roots Cd content showed linear correlationship with ammonium acetate Cd content .Conclusion] In order to reduce brown rice Cd content,agro-nomic measures or adding passivator,could be implemented to reduce ammonium acetate Cd content in time after the booting stage of rice into the filling stage.