镉污染条件下不同pH处理对大豆生长发育及产品质量的影响

利用沈阳市于洪区镉(Cd)污染的土壤,以盆栽试验的方式,研究了不同pH处理对大豆生长发育及产品质量的影响。结果表明:随着土壤pH的升高,株高、干物重及单株产量都有先增加后减少的趋势,单株产量以pH 7.18~7.96较高。各部位镉的累积含量都表现出根>叶>茎>子粒,并且pH值越高各部位的累积程度越低。全部处理子粒中的累积范围为0.095~0.872 mg/kg,从pH为7.54开始子粒中镉的累积含量达到限量标准以内,分别为7.54(0.182 mg/kg),7.96(0.095 mg/kg),8.41(0.098 mg/kg),8.93(0.097 mg/kg)。说明土壤pH>7.54时对抑制镉吸收有一定的效果。同时子粒中镉含量(y)与pH(x)之间具有较好的指数关系y=76.76e-0.78x(r=0.95**),单株产量(y)与pH(x)存在较好的曲线关系y=-2.19x2+32.90x-112.7(r=0.996**),pH>8.41单株产量有明显降低的趋势,抑制重金属镉吸收土壤的适宜pH为7.54~8.41。

Influence of Different pH on the Growth and Product Quality of Soybean under Cd Pollution

With Cd-contaminated soil of Shenyang Yuhong region,a pot research was conducted to study the influence of different pH on the yield and quality of soybean under Cd pollution.The results showed that: with the increase of pH,height,dry matter and yield of soybean were increased first then decreased.Single plant production was higher when pH was between 7.18 and 7.96.The accumulative content of cadmium in various parts has shown: root> leaf> stem> grain,and the greater the pH,the lower the accumulative content of different parts.The accumulation range of the treated grain was between 0.095 ans 0.872 mg/kg.From pH 7.54,Cd accumulation in grain reached a standard limit,and they were respectively 7.54(0.182 mg/kg),7.96(0.095 mg/kg),8.41(0.098 mg/kg) and 8.93(0.097 mg/kg).It showed that when soil pH was greater than 7.54,the inhibition effect of Cd on the absorption was obvious.In the meantime,there was a good exponential relationship between Cd content(y) and Ph(x): y=y=76.76e-0.78x(r=0.95**),there was a good curve relationship between per plant yield(y) and pH(x): y=-2.19x2+32.90x-112.7(r=0.996**),and plant yield significantly decreased when pH was more than 8.41.Thus,in order to inhibit the absorption of Cd,the optimal range of soil pH should be located within 7.54～8.41.