ESTIMATION OF NITROGEN LOAD FROM AGRICULTURAL ACTIVITY IN 1920S BY USING AGRICULTURAL INFORMATION RECORDED IN PREVIOUS LITERATURES

Abstract

In this study, the amount of nitrogen load derived from agricultureal activties in 1928 and 1932 were estimated by analyzing agricultural information recorded in previous literatures. The amounts of nitrogen load from paddyfields and farms were about 1/10 and 1.4 as that in 2006, respectively. These results indicate that it is able to estimate the previous nitrogen load by detailed analysis of agricultural information recorded in past literatures. It is considered that the agricultural information from previous literatures is useful for goal setting of reduction target of nitrogen load.