不同来源有机物料降低水稻镉积累的效果

采用盆栽试验,研究了水稻生长过程中添加紫花苜蓿与蚓粪对土壤理化性质及水稻镉积累的影响。结果表明,添加外源有机物料使土壤Eh值显著下降,当有机质添加量相同时,紫花苜蓿处理组土壤Eh值显著低于蚓粪处理组;在水稻生育前期紫花苜蓿处理组较蚓粪处理组土壤pH下降更为显著,进入抽穗扬花期后两者无显著差异。添加外源有机物料均使土壤中高活性态镉向低活性态镉转化,当有机质添加量相同时,紫花苜蓿处理组土壤低活性态镉含量总体上低于蚓粪处理组。与不添加外源有机物料对照相比,添加外源有机物料的处理水稻各部位镉含量显著降低;当有机质添加量相同时,紫花苜蓿处理组水稻根、茎叶、籽粒镉含量较蚓粪处理组降幅更显著。

Decreasing Effects of Different Sources of Organic material on Cadmium Accumulation in Rice

A pot experiment was conducted to study the effects of adding alfalfa and vermicompost on the physical and chemical properties of soil and the accumulation of cadmium in rice during the growth of rice. The results showed that, the soil Eh value decreased significantly with the addition of organic matter, with the more by alfalfa than by vermicompost under the same organic matter addition level. The soil pH of the alfalfa treatment group was lower than that of the vermicompost treatment group in the early stage of rice growth, and there was no significant difference between the two treatment after the heading stage. The addition of external organic materials could transform the highly active cadmium to the low active cadmium in the soil. Compared with the control without adding exogenous organic materials, the cadmium content in each part of the rice treated with exogenous organic materials was significantly reduced. Moreover, the cadmium content in each part of the rice plant in the alfalfa treatment group was significantly lower than that in the vermicompost treatment group under the same organic matter addition level.