磷肥对土壤中镉的植物有效性影响及其机理

应用生态学报 ›› 2012, Vol. 23 ›› Issue (06): 1585-1590.

磷肥对土壤中镉的植物有效性影响及其机理

刘昭兵^1,2,纪雄辉^1,2**,彭华^1,2,田发祥^1,3,吴家梅^1,3,石丽红^1,2

(¹湖南省农业科学院土壤肥料研究所, 长沙 410125; ²农业部长江中游平原农业环境重点实验室, 长沙 410125; ³中南大学研究生院隆平分院, 长沙 410125)

出版日期:2012-06-18 发布日期:2012-06-18

Effects of phosphorous fertilizers on phytoavailability of cadmium in its contaminated soil and related mechanisms.

LIU Zhao-bing^1,2, JI Xiong-hui^1,2, PENG Hua^1,2, TIAN Fa-xiang^1,3, WU Jia-mei^1,3, SHI Li-hong^1,2

(¹Hunan Soil and Fertilizer Institute, Hunan Academy of Agricultural Sciences, Changsha 410125, China; ²Ministry of Agriculture Key Laboratory of AgriEnvironment in the Midstream of Yangtze Plain, Changsha 410125, China; ³Longping Branch of Graduate School of Central South University, Changsha 410125, China)

Online:2012-06-18 Published:2012-06-18

摘要/Abstract

摘要： 为寻求保障镉污染农田稻米质量安全的有效措施，采用盆栽方法研究了低镉磷肥(Cd＜0.2 mg·kg^-1)及不同施磷量(0.10、0.20 g P₂O₅·kg^-1)对污染稻田土壤中(潮泥田)镉的植物有效性影响，并探讨了相关机理.结果表明：在0.10 g·kg^-1磷剂量水平下，与对照(无磷肥)相比，钙镁磷和磷酸二氢钾处理显著提高了土壤pH和降低了土壤镉活性，钙镁磷和过磷酸钙处理显著降低了水稻对镉的吸收累积；当施磷量增至0.20 g·kg^-1时，磷酸氢钙处理显著提高了土壤pH和降低了土壤镉活性，钙镁磷、磷酸二氢钾和磷酸氢钙处理下DTPA提取态镉含量降低11.8%、9.8%和11.8%，NH₄OAc提取态镉含量降低9.5%、7.1%和7.1%；5种磷肥处理均显著降低了水稻茎叶中镉含量(降幅24.9%～50.8%)，除磷酸氢钙处理外，糙米镉含量的降幅均达到显著水平，钙镁磷和过磷酸钙处理下糙米镉含量接近国家粮食卫生标准(GB 2715—2005).5种供试磷肥中，能提高土壤pH的磷肥(钙镁磷、磷酸二氢钾和磷酸氢钙)降低土壤镉有效性的效果显著，含钙磷肥(钙镁磷和过磷酸钙)降低水稻镉积累的效果较好.磷肥化学性质的差异可能是影响其效果的主要原因，选择碱性含钙磷肥对控制污染农田中作物吸收累积镉更有效.

Abstract: To explore an effective measure to ensure the safety of rice quality in cadmium (Cd) contaminated farmland, a pot culture experiment was conducted to study the effects of of low Cd content (Cd＜0.2 mg·kg^-1) phosphorous fertilizers with an application rate of 0.10 or 0.20 g P₂O₅·kg^-1 on the phytoavailability of Cd in its contaminated paddy soil, with the related mechanisms discussed. Compared with no phosphorous fertilization, applying 0.10 P₂O₅·kg_-1 of calcium magnesium phosphate (CMP) and monopotassium phosphate (MKP) increased soil pH and decreased soil available Cd content significantly, and CMP and calcium superphosphate (CSP) decreased the Cd accumulation in rice significantly. When the application rate was up to 0.20 g P₂O₅·kg^-1, calcium hydrogen phosphate (CHP) increased the soil pH and decreased the soil available Cd content significantly, and CMP, MKP, and CHP decreased the DTPAextractable soil Cd content by 11.8%, 9.8%, and 11.8%, and the NH₄OAcextractable soil Cd content by 9.5%, 7.1%, and 7.1%, respectively. All test phosphorous fertilizers could significantly decrease the stem and leaf Cd contents, with a decrement of 24.9%-50.8%, and except CHP, the others could significantly decrease the Cd content of brown rice. With the application CMP and CSP, the Cd content of brown rice was close to the National Hygienic Standard for Grains (GB 2715-2005). Among the test phosphorous fertilizers, those can increase soil pH (CMP, MKP, and CHP) could significantly decrease the availability of soil Cd significantly, and those containing calcium (CMP and CSP) were more effective in decreasing the Cd accumulation in rice. The efficiency of the phosphorous fertilizers was mainly determined by their chemical properties. Alkaline calciumcontaining phosphorous fertilizers were more effective in decreasing the Cd absorption and accumulation in rice plant in Cdcontaminated farmland.

刘昭兵1,2,纪雄辉1,2**,彭华1,2,田发祥1,3,吴家梅1,3,石丽红1,2. 磷肥对土壤中镉的植物有效性影响及其机理[J]. 应用生态学报, 2012, 23(06): 1585-1590.

LIU Zhao-bing1,2, JI Xiong-hui1,2, PENG Hua1,2, TIAN Fa-xiang1,3, WU Jia-mei1,3, SHI Li-hong1,2. Effects of phosphorous fertilizers on phytoavailability of cadmium in its contaminated soil and related mechanisms.[J]. Chinese Journal of Applied Ecology, 2012, 23(06): 1585-1590.