Abstract
A simulator assessing the environmental impacts of agricultural activities in Miyako-Island was developed. The input data are cultivated acreage of each crop and the number of cows. The outputs are 1) inventories of environmental loads such as CO2, CH4, N2O, NOx, SOx, NH3 and NO3−, 2) the environmental impacts at midpoint such as global warming potential, acidification potential, effect on groundwater and energy consumption and 3) the environmental impacts calculated according to the LIME method at midpoint. The features of this simulator are 1) it enable its users to estimate the environmental impacts with a small number of input data since default data based on the present conditions of agricultural activities in Miyako-Island are included in the simulator, 2) it also allows its user to input their actual data in place of the default ones for more precision and 3) it gives the information about the environmental impacts by changing the amounts of synthetic fertilizers applied and the crop yields.
The environmental impacts by a typical farmer’s activities in Miyako-Island were estimated with this simulator and the results are following: 1) a significant fraction of CO2 emissions was originated from concentrated feed, chemical fertilizer, diesel for agricultural machinery and waste plastics and 2) Global warming potential was estimated as 44.1 t-CO2eq/y and main contributors were CH4 from rumination of cattle and N2O from manure treatment. Moreover five different scenarios on chemical fertilizer usage and cattle breeding were used for simulations and the results were discussed in the paper.
