供试7种提取剂的最佳提取条件是:提取温度均为(25±1)℃;提取时间为DTPA 2 h,醋酸铵30 min,其余5种提取试剂60 min;提取时的土液比为蒸馏水和DTPA 1∶2,醋酸铵1∶10,其余4种提取试剂1∶5。DTPA作为提取剂时,盆栽作物的吸镍量与有效镍提取量之间的相关性达到极显著水平,并好于其它试剂。DTPA和EDTA作为提取剂时,有效镍提取量与植株干物重之间均达极显著的负相关,且相关系数高于其他试剂。考虑到用DTPA作提取剂时,可以同时测定铜、锌、铁、锰多种金属元素,因此黑土中有效态镍的最佳提取试剂是DTPA,最佳提取条件为:温度(25±1)℃、土液比1∶2、180次min-1往复振荡提取2 h。 The optimal extraction conditions for the seven extractants were as follows: the extraction temperature was (25 ± 1) ℃; the extraction time was DTPA 2 h, ammonium acetate 30 min, and the other five extraction reagents 60 min; Distilled water and DTPA 1: 2, ammonium acetate 1:10, the remaining four extraction reagents 1: 5. When DTPA was used as the extractant, the correlation between the amount of nickel absorbed by the potted plants and the amount of available nickel was extremely significant and better than the other reagents. When DTPA and EDTA were used as extractants, there was a significant negative correlation between available nickel extract and plant dry weight, and the correlation coefficient was higher than other reagents. Considering that when DTPA is used as extractant, copper, zinc, iron and manganese can be determined simultaneously. Therefore, the best extraction reagent of effective nickel in black soil is DTPA. The optimum extraction conditions are: temperature (25 ± 1) ℃, liquid-to-liquid ratio 1: 2, 180 times min-1 reciprocating oscillation extraction 2 h.