%0 Journal Article
%T Role of wetlands in mitigating the tradeŠ\off between crop production and water quality in agricultural landscapes
%A Akira Yoshioka
%A Ayato Kohzu
%A Bunkei Matsushita
%A Haruko Ando
%A Haruyo Yamaguchi
%A Kazuhiro Komatsu
%A Keiichi Fukaya
%A Koichi Shimotori
%A Megumi Nakagawa
%A Mirai Watanabe
%A Natsuko Kondo
%A Nobuko Saigusa
%A Noriko Takamura
%A ShinŠ\ichiro S. Matsuzaki
%A Takahiro Sasai
%A Takeshi Osawa
%A Taku Kadoya
%A Toshikazu Kizuka
%J Ecosphere - Wiley Online Library
%D 2019
%R https://doi.org/10.1002/ecs2.2918
%X Agriculture faces the great challenge of developing strategies to maintain production while simultaneously reducing environmental impacts. The tradeŠ\off between crop production and water quality services is one of the most serious issues facing agriculture, and interest in achieving win¨Cwin outcomes through management of ecosystem services is growing. Although wetlands can reduce nitrogen loads, it is unclear whether maintaining and restoring wetlands can ameliorate the tradeŠ\off between crop production and water quality and thereby increase the likelihood of win¨Cwin outcomes. We defined the orthogonal residuals from the regression line relating the tradeŠ\offs between two conflicting services as the degree to which the tradeŠ\off was mitigated (mitigation effectiveness score). The more positive the residual, the higher mitigation effectiveness score, and the greater the potential to mitigate the tradeŠ\off. We measured nitrate concentrations, as an indicator of water quality, five times during summer and winter across 49 subŠ\watersheds of the watershed of Lake Kasumigaura, which is highly nitrogenŠ\loaded by agriculture. We quantified the mitigation effectiveness score from the tradeŠ\off relationships between cropland area and nitrate concentrations, and we also identified landscape and environmental factors that affected these scores. Some subŠ\watersheds in our study had high cropland cover but low nitrate concentrations. Overall, we found that mitigation effectiveness scores were positively associated with wetland cover at all sampling times. Other factors, including covers of paddy rice fields, abandoned rice fields, and impervious surfaces, and dissolved organic carbon concentrations, had no significant effects on mitigation effectiveness scores, although these factors were considered to increase nitrogen removal. Our findings suggest that maintaining and restoring wetlands might mitigate the tradeŠ\off between crop production and water quality and thereby enhance the likelihood of win¨Cwin outcomes in agricultural landscapes. Because wetland area has decreased, flooding or ponding abandoned rice fields may be an important alternative management option. The nitrate concentrations we observed met the water quality standard for drinking water, but the fact that they sometimes exceeded the nitrogen environmental target adopted within Lake Kasumigaura in terms of eutrophication suggests that simultaneous reduction of croplands and fertilizer inputs should still be encouraged. Agricultural systems provide humans with food, forage, and bioenergy, and they are
%U https://esajournals.onlinelibrary.wiley.com/doi/full/10.1002/ecs2.2918