通过试验对土壤速效磷测定过程中存在的待测液脱色问题进行探讨,初步得出以下结果:(1)样品中加入0.25g含磷活性炭,对待测液的脱色效果较好,但对养分含量较低的土样测定结果有一定的影响,使样品的测定结果大约增加了1mg/kg。(2)在没有无磷活性炭的情况下,对于有颜色的待测液,可根据颜色深浅,适当减少待测液吸样量进行测定,对样品的测定结果没有影响。 Through the experiment, the decolorization of the tested liquid in the determination of available phosphorus in soil was discussed. The results were as follows: (1) 0.25g phosphorus-containing activated carbon was added to the sample, The lower soil sample results have a certain impact, so that the sample results increased by about 1mg / kg. (2) In the absence of phosphorus-free activated carbon, for the color of the test solution, according to the color depth, appropriate to reduce the amount of sample fluid to be measured, the sample did not affect the measurement results.