The yearly changes in environmental impacts of Japanese dairy farming were evaluated with original sheet data of survey on cost of milk production, conducted by Ministry of Agriculture, Forestry and Fisheries. Global warming, acidification and eutrophication potentials in Hokkaido and the areas except Hokkaido were evaluated by life cycle assessment (LCA). Fourteen year's original sheet data, from 1979 to 1992, were used in this study. The functional unit of LCA was one metric ton of milk produced. The production processes of chemical fertilizers, agrochemicals, materials, machineries and facilities, cultivation of purchased and self-supplied feeds, animal management and manure management were contained within the system boundary of this study. Multiple regression analysis was executed to estimate global warming, acidification and eutrophication potentials with cost of feeds, beddings, electricity and fossil fuels, facilities and machineries, the number of milking cows and the amount of milk produced. And the equations were used to evaluate the environmental impacts from 1993 to 2006. The amount of milk produced per farm was increased within the period from 1979 to 2006. Global warming potentials were decreased after 1982, and became constant after 1997 in Hokkaido and the areas except Hokkaido. The contributions of rumen fermentation and purchased feeds to global warming were high, and the contributions of fossil fuels (Hokkaido) increased from 1979 to 1992. Eutrophication potentials were higher in Hokkaido, but no difference was observed in 1992. From this study, the increase of milking cows per farm, the genetic improvement of milking performance, the quality improvement of feeds, the reduction of methane emission by rumination, the improvement of self-sufficiency of feeds and the greater use of composting methods that have low emission factors were important for reductions of environmental impacts.
Environmental impacts of beef-fattening systems using local food by-product feeds were compared with those using concentrate feeds by a life cycle assessment method. Apple juice pulp and wheat bran were the local food by-product feeds evaluated. Cultivation, transport, processing, animal management, digestion process and waste management were used for estimations of global warming potential, acidification potential and eutrophication potential. Economic worth was used to allocate the environmental burden between juice and pulp and between flour and bran. The functional units for feed production and beef cattle fattening were 1 metric ton of total digestible nutrients and 1 kg of body weight gain, respectively. Contributions to global warming and acidification were high in the concentrate feeds beef-fattening system. Fossil fuel consumption by overseas transport influenced these impacts. Fossil fuel consumption during drying of apple juice pulp enhanced the global warming and acidification effects. As manure was excessively applied for grass and apple cultivation, contributions of grass silage and apple juice pulp to eutrophication were high. The use of local food by-products as feeds reduced global warming and acidification potential. The application of optimum amounts of chemical fertilizers and manure is important for reducing eutrophication potential.
The Chugoku and Shikoku Regional Agricultural Administration Office of the Agriculture, Forestry and Fisheries Ministry conducted a survey on two patches of paddy fields, one unused and one cultivated, in Izumo and Unnan, Shimane Prefecture, between June 2006 and August 2007 as a part of a feasibility study of maintaining and strengthening multiple functions of paddy fields. Using the data on the runoff collected during the survey, the amount of soil runoff of each area at 20-minute intervals was calculated. Then, these results and data on rainfall per hour as measured at the rain and water observatory at the nearest location were used to tally the total volume of soil runoff in the year between August 2006 and August 2007, including winter months when rainfall was not measured, in which data for periods of continuous rainfall and for cultivated paddy field patches, data for before soil puddling, during soil puddling, and after soil puddling were tallied separately. More so, the existence of runoff water on the observation paddy field before the fall of rain was made out. We found that periods of continuous rainfall accounted for about 70 percent of the annual amount of soil runoff for both cultivated and unused paddy fields, soil runoff occurred when paddies were flooded, and that soil runoff was minimal during soil puddling and shortly before and after soil puddling.In order to determine the suitableness of the Universal Soil Loss Equation (USLE) with a modified coefficient adapted to the actual condition in Japan for the observation paddy fields, the amount of rainfall erosion and soil runoff for each period of continuous rainfall was tallied, and the correlation coefficient of both were obtained. As a result, a correlation coefficient of 0.9 and higher was found between the amount of rainfall erosion and soil runoff, indicating that the USLE can most probably be applied to the two observation paddy fields. Further, for the observation paddy fields (cultivated paddy), all paddy-related coefficients in the USLE were calculated as was done with dry fields. The calculated coefficients indicated that cultivated rice paddies were able to retain a greater amount of soil when used as such than when converted to a dry, hillside farm maintaining the present geographical features.
We describe a methodology for detecting rice planted plots using SAR satellite, COSMO-SkyMed, with GIS data. Two SPOTLIGHT-2 mode imageries (1m/pixel, 10km x 10km), one for transplanting season, the other for rice growing season, were used to detect rice planted plots in the study site (about 30 ha) in Japan. In the site, we obtained land cover data in every plot through conducting ground truth survey which is synchronized with the image acquisition. We evaluated the accuracy though comparing three different methods: A) image interpretation with two single imageries, B) image interpretation with color composite imagery, and C) semi-automatic detection with color composite imagery. The results show that the high accuracies, more than 98% (agreed area ratio), were obtained by methods B and C.