Soil databases for agro-environmental researches in NIAES, Japan

Soil maps and soil data are major elements of the fundamental information of land. In Natural Resources Inventory Center at NIAES, databases for national soil survey programs and other individual soil researches have been developed. To deal with environmental issues effectively, those databases have been used in agro-environmental researches. In the water quality researches, fundamental studies of water and nitrate dynamics in soil profiles, estimation of period of nitrate passage through the soil profile to underground water table were carried out. A method of grouping and mapping soils that includes properties of deep soil layers was developed. Also, an evaluation method of deep soil layers for water conservation purpose was developed. In the researches for chemical pollution, some models which simulating the fate and transport of pesticides in paddy fields were developed in Japan. In those models and the researches for Persistent Organic Pollutants (POPs), correlation between chemical substances behavior in soil and soil organic carbon contents were found, and the organic carbon contents data of soil database were used for the studies. In the heavy metal researches, the contents of heavy metals in soils were calculated using soil databases, and the zoning maps of cadmium contamination risk were developed. In the Global warming researches, carbon stocks of soils were calculated using soil databases. Also two models (Rothamsted Carbon Model（Roth C model） and DeNitrification-DeComposition (DNDC) model) were modified to adapt to Japanese paddy rice cultivation and Andosols. A soil survey project that is designed to estimate the changes of carbon stocks of arable land is started in 2008.