In general, the described method is considered appropriate as the evaluation test of contaminated soil by using germination and crop test. Also, it will be a right idea that the lettuce germination test is chosen as one of biological evaluation tests of soil quality against contamination.


However, we are wondering if it is right to choose only lettuce as a test plant for this kind of evaluation. One alternative idea is that several plants should be chosen based on the variety of climates and soil environments of all over the world.


Our second comment is about pH. We should pay attention to the fact that this kind of germination test is greatly influenced by pH of culture media (soil) for both test and control. From this point, there may be a need for the additional test, i.e., a test to evaluate damage percentage due to pH based on the germination percentage and weight of plant on culture media of several different pH.


Our last comment is about the aim of this CD. We feel it is not distinguished from the one of N176 NWI Soil quality - Chronic toxicity in higher plants.