... paddy field was converted to the equivalent area of cultivated land based on their ratio of unit loads of pollution for COD, TP and TN, and were finally summed up to get the agriculture area. ... loads of pollution (Table 3) from paddy field and cultivated land for COD, TN and TP. For TDS, the area of paddy field and cultivated land were summed up. While selecting the explanatory variables, ... plan; indicator and explanation, Japan Society of Sewerage System. (in Japanese) MLIT (Ministry of Land, Infrastructure, Transport and Tourism) (2003). Block-wise strategy effect analysis, Fifth...