27 Scenario Analysis of Environmental Impact of Paddy Rice …
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form of fertilizers (Fig. 27.3). The P loss potential in rice paddies was estimated
similarly to N loss estimation, with the nitrogen and phosphorus contents of rice
grain and hulls being determined from the ingredient database of biomass (National
Research Institute of Agricultural Engineering 2006).
27.2.4 Data Source and Scenario of Paddy Rice Farming
Systems
The amount of the agricultural material consumption data of the process model for the
paddy rice farming system by life-cycle inventory analysis was collected from statistically based data (AFFTIS 1997). The environmental conservation practices evaluated in paddy rice farming were of two types: (1) using organic fertilizer and reduced
crop protection chemicals (practices at Shiga prefecture), and (2) using composted
farmyard manure instead of artificial fertilizers (practices at Tochigi prefecture).
(1) Scenario analysis of organic fertilizer application in the paddy rice farming
system
In Shiga prefecture, environmentally friendly conservation-type practices are applied
to the paddy rice farming system. The organic fertilizer is made from organic residuals, such as feather meal and rapeseed oil cake, that has a nutrient composition
similar to that of artificial fertilizers, and that is markedly higher than that from
composted animal manure.
In the analysis of the organic fertilizer application scenario, we evaluated the environmental impacts of these conservation practices, that reduced the amount of artificial fertilizers and crop protection chemicals applied to less than 50% of the rate used
in the conventional paddy rice farming system. The data used in the process model for
comparing environmental impacts between the organic fertilizer use scenario and the
conventional scenario were collected from the research report of field experiments
in Shiga (Table 27.1) (Hasukawa et al. 2009).
The conventional scenario utilized 450 kg/ha of artificial fertilizers, with the
amount of nitrogen applied being 76 kg/ha, whereas the total amount of crop protection chemicals used was 38.9 kg/ha, consisting of 14 different components. The yield
of brown rice was 5670 kg/ha from the conventional scenario. The organic fertilizer application scenario used 800 kg/ha of organic fertilizer, representing 70 kg/ha
nitrogen being applied. The crop protection chemicals were applied to the organic
fertilizer scenario at a total of 16.6 kg/ha for six components. The difference in the
brown rice yield from the two scenarios was minimal. The yield of brown rice was
5460 kg/ha at the organic fertilizer application scenario. The target yield from environmental conservation-type paddy rice farming system was 7400 kg/ha under the
guidelines for rice production in Shiga. Hence, both scenarios were acceptable for
analysis in this study, from the quantitative point of input materials and production
yield.
419
form of fertilizers (Fig. 27.3). The P loss potential in rice paddies was estimated
similarly to N loss estimation, with the nitrogen and phosphorus contents of rice
grain and hulls being determined from the ingredient database of biomass (National
Research Institute of Agricultural Engineering 2006).
27.2.4 Data Source and Scenario of Paddy Rice Farming
Systems
The amount of the agricultural material consumption data of the process model for the
paddy rice farming system by life-cycle inventory analysis was collected from statistically based data (AFFTIS 1997). The environmental conservation practices evaluated in paddy rice farming were of two types: (1) using organic fertilizer and reduced
crop protection chemicals (practices at Shiga prefecture), and (2) using composted
farmyard manure instead of artificial fertilizers (practices at Tochigi prefecture).
(1) Scenario analysis of organic fertilizer application in the paddy rice farming
system
In Shiga prefecture, environmentally friendly conservation-type practices are applied
to the paddy rice farming system. The organic fertilizer is made from organic residuals, such as feather meal and rapeseed oil cake, that has a nutrient composition
similar to that of artificial fertilizers, and that is markedly higher than that from
composted animal manure.
In the analysis of the organic fertilizer application scenario, we evaluated the environmental impacts of these conservation practices, that reduced the amount of artificial fertilizers and crop protection chemicals applied to less than 50% of the rate used
in the conventional paddy rice farming system. The data used in the process model for
comparing environmental impacts between the organic fertilizer use scenario and the
conventional scenario were collected from the research report of field experiments
in Shiga (Table 27.1) (Hasukawa et al. 2009).
The conventional scenario utilized 450 kg/ha of artificial fertilizers, with the
amount of nitrogen applied being 76 kg/ha, whereas the total amount of crop protection chemicals used was 38.9 kg/ha, consisting of 14 different components. The yield
of brown rice was 5670 kg/ha from the conventional scenario. The organic fertilizer application scenario used 800 kg/ha of organic fertilizer, representing 70 kg/ha
nitrogen being applied. The crop protection chemicals were applied to the organic
fertilizer scenario at a total of 16.6 kg/ha for six components. The difference in the
brown rice yield from the two scenarios was minimal. The yield of brown rice was
5460 kg/ha at the organic fertilizer application scenario. The target yield from environmental conservation-type paddy rice farming system was 7400 kg/ha under the
guidelines for rice production in Shiga. Hence, both scenarios were acceptable for
analysis in this study, from the quantitative point of input materials and production
yield.