【摘要】 采用水培+土培的方法研究了钴对蔬菜的毒害临界值。首先从18种福建常见蔬菜中筛选出钴高敏感蔬菜,再通过土培试验研究土壤钴对高敏感蔬菜的毒害临界浓度。结果表明,在水培条件下钴对蔬菜生长存在较低浓度的刺激效应和高浓度的抑制效应。综合表观症状和蔬菜地上部生物量减少20%的效应浓度值(EC20)确定,早熟5号大白菜(Brassica pekinensis)和黄瓜(Cucumis sativus)为钴高敏感作物。以黄瓜为指示作物的土培试验表明,钴对黄瓜未表现出增产效应,随着钴添加量的增加,黄瓜地上部生物量显著下降。以黄瓜地上部减产10%和野外土壤有效钴和全钴的回归关系为依据,确定土壤钴毒害临界值为:土壤有效钴(DTPA)为2.7mg·kg-1,土壤全钴含量为98mg·kg-1。更多还原

【Abstract】 By the methods of water culture and soil culture,this paper studied the threshold values of cobalt (Co) toxicity to vegetables. Water culture was performed to select the most Co-sensitive vegetables from the 18 vegetable species commonly cultivated in Fujian Province,and soil culture was conducted to determine the threshold values of soil Co toxicity to the selected vegetable species. Under water culture,low concentration (0.01 and 0.1 mg·L-1) Co stimulated vegetable growth,while high concentration Co had toxic effects. Based on the apparent symptoms and the EC20 values (effective concentration causing a 20% decrease of shoot biomass),Chinese cabbage (Brassica pekinensis) and cucumber (Cucumis sativus) were the most sensitive vegetables. In the followed soil culture with cucumber,no obvious stimulating effects of Co were observed. With the increasing concentration of added Co,the shoot biomass of cucumber decreased significantly. Based on the EC10 (effective concentration causing a 10% decrease of shoot biomass) and the regression between soil DTPA-Co and total Co in the field,the threshold values of soil Co toxicity were estimated to be 2.7 mg·kg-1 (DTPA-Co) and 98 mg·kg-1 (total Co).更多还原