In situ determination of crop productivity in metal- contaminated, remediated, and reclaimed soils: Significance of ecotoxicological data on assessing soil quality

Soil quality assessment is generally performed using a combination of physical, chemical, and biological indicators in a target area, and the indicator measurement data are subjected to sequential processes such as scoring, weighting, and indexing. The selection of indicators is one of the important processes, and their actual application should be carefully considered. The techniques of soil remediation can affect the measurement of traditional biological indicators. In the present study, we aimed to evaluate the applicability of ecotoxicological indicators for soil quality assessment. The paddy and upland soil plots were constructed using contaminated-, remediated-, and reclaimed-soils on field, and the soil quality indicators were measured. We designed a soil quality assessment system including ecotoxicological indicators, and the soil quality index (SQI) was calculated using indicator measurement data of each plot. The SQI with or without ecotoxicological indicators was directly compared with in situ crop productivity. We found that relatively higher SQI can be obtained with ecotoxicological indicators than that without them, and soil quality indexing with ecotoxicological indicators showed high correlations with in situ crop productivity in paddy and upland soil plots.