磷钙基肥对水稻根表铁膜及稻米中Cd含量的影响  

Effects of Phosphorus-Calcium Based Fertilizers on Iron Plaque on Rice Root Surface and Cd Content in Rice Grain

作　　者：徐军辉 宋慧娟 陈丽妮 梁君依 邓潇 彭亮[2] XU Junhui;SONG Huijuan;CHEN Lini;LIANG Junyi;DENG Xiao;PENG Liang(Agriculture and Rural Bureau of Heshan District,Yiyang,Hunan 413002,China;College of Environment and Ecology,Hunan Agricultural University,Changsha,Hunan 410128,China)

机构地区：[1]益阳市赫山区农业农村局,湖南益阳413002 [2]湖南农业大学环境与生态学院,湖南长沙410128

出　　处：《作物研究》2023年第4期322-327,共6页Crop Research

基　　金：国家自然科学区域联合基金(U20A20108);国家重点研发计划项目(2022YFD1700102)。

摘　　要：稻米中镉超标是农业环境领域非常重要的课题,利用肥料调控技术,降低稻米中Cd含量具有重要意义。本研究利用磷酸钙镁和石灰配成磷钙基肥,研究其施用浓度对水稻根表铁膜特征及稻米中Cd含量的影响。结果显示,施加0.2‰~1.0‰磷钙基肥对水稻株高和全根的生长状况影响不大,但1.2‰浓度下会影响植株根的发育。基肥的施用会提升土壤pH,降低土壤Cd的有效浓度,进而降低植株中各器官和稻米中Cd含量。对于pH 4.7,总Cd含量为1.2 mg/kg的稻田土壤,当施用1.0‰磷钙基肥时,稻米中Cd为0.124 mg/kg,达到国家粮食安全标准。0.2‰~0.5‰的基肥能促进水稻根表铁膜的形成;超过0.8‰的磷钙基肥施加,会降低Fe和Mn的有效性,阻止铁膜的形成。铁膜对Cd的吸收阻控主要与铁膜中Fe含量相关,而与Mn关系较低。因此,施用磷钙基肥是实现Cd超标农田中水稻安全生产的有效措施之一。The problem of excessive cadmium in rice grain is a very important issue in the field of agricultural environment.It is of great significance to develop fertilizer control technology and reduce the cadmium concentration in rice grain.This research used calcium magnesium phosphate and lime to form a phosphorus-calcium based fertilizer,and stu-died the effect of application concentration on the characteristics of rice iron plaque and Cd content in rice.The results showed that the application of 0.2‰-1.0‰ phosphorus-calcium base fertilizer had little effect on the height of rice plants and the growth status of whole roots,but at a concentration of 1.2‰,it would affect the growth of plant roots.The application of base fertilizer will increase the soil pH,reduce the bioavailable concentration of soil Cd,and thereby reduce the Cd content in various organs of plants and rice.For paddy soil with a pH of 4.7 and a total Cd content of 1.2 mg/kg,when 1.0‰ phosphorus-calcium base fertilizer was applied,the Cd content in rice was 0.124 mg/kg,far lower than the national food security regulation of 0.2 mg/kg.The basal fertilizer of 0.2‰-0.5‰ promoted the formation of iron plaque on the root surface of rice,while the application of basal fertilizer higher than 0.8‰ reduced the effectiveness of Fe and Mn and prevented the formation of iron plaque.The absorption resistance control of Cd by iron plaque was mainly related to the Fe content in the iron plaque,while the relationship with Mn was relatively low.Therefore,applying phosphorus-calcium based fertilizers was one of the effective methods to achieve the safe utilization of rice in farmland with Cd exceeding standards.

关 键 词：水稻 施肥 镉 根表铁膜 钝化剂 

分 类 号：S511.062[农业科学—作物学]