Continuum of Risk Analysis Methods to Assess Tillage System Sustainability at the Experimental Plot Level

Environmental and economic risks assessment under climate changes for three land uses scenarios analysis across Teshio watershed, northernmost of Japan

Land use and climate changes affect on the economy and environment with different patterns and magnitudes in the watershed. This study used risk analysis model stochastic efficiency with respect to a function (SERF) to evaluate economic and environmental risks caused by four climate change scenarios (baseline, small-, mid- and large changes) and three land uses (paddy dominated, paddy-farmland mixture and farmland dominated for agriculture) in Teshio watershed in northern Hokkaido, Japan. Under the baseline climate conditions, the lower ranking of economic income of crop yield and higher ranking of pollutant load from agricultural land were both predicted in paddy dominated for agriculture, suggesting that the paddy dominated system caused higher risks of economic and environmental variables compared to other two land uses. Increase of temperature and precipitation increased crop yields under all three climate changes which resulted in increase of the ranking of economic income, indicating that those climate changes could reduce economic risk. The increased temperature and precipitation also accelerated mineralization of organic nutrient and nutrient leaching to river course of Teshio which resulted in increase of the ranking of pollutant load, suggesting that those climate changes could lead to more environmental risk. The rankings of economic income in mid- and large changes of climate were lower than that in small change of climate under paddy-farmland mixture and farmland dominated systems due to decrease of crop yield, suggesting that climate change led to more economic risk. In summary, the results suggested that increase in temperature and precipitation caused higher risks of both economic and environmental perspectives, and the impacts was higher than those of land use changes in the studied watershed. Those findings would help producers and watershed managers to measure the tradeoffs between environmental protection and agricultural economic development for making decision under land use and climate changes.