title: No-tillage effects on N and P exports across a rice-planted watershed.
abstract: No tillage (NT) can be used as a management tool to alleviate the negative effects of agricultural practices on the environment by reducing the runoff volume and nutrient exports. The main objective of this research was to quantify the effect of NT on nitrogen (N) and phosphorus (P) exports across a rice-planted watershed using the soil and water assessment tool (SWAT) model. Results show that total N and P runoff exports from rice fields across the watershed ranged from 7.2 to 22.8 kg N/ha and 0.56 to 6.80 kg P/ha, respectively, over five rice-growing seasons under conventional tillage (CT) practice. The adoption of NT reduced the runoff volume, and the total N and total P exports by 25.9, 8.5, and 7.8 %, respectively, compared with the total exports under CT practice in the same study area. Rice yields were reduced by 0.7-1.9 % within the first 4 years after the adoption of NT, but began to rise in the fifth year. These results suggest that a long-term period of NT practice is necessary to reduce N and P exports without comprising the rice yield on rice-planted watersheds. In addition, the benefits of implementing NT practice alone were limited, and other practices, such as water and nutrient management, should be combined with NT practice.
authors.affiliation: College of Environmental and Resource Sciences, Zhejiang University, Hangzhou, 310058, China. liang410@zju.edu.cn.|Key Laboratory for Water Pollution Control and Environmental Safety, Zhejiang Province, Hangzhou, 310058, China. liang410@zju.edu.cn.
authors.forename: Xinqiang
authors.initials: X
authors.lastname: Liang
authors.affiliation: College of Environmental and Resource Sciences, Zhejiang University, Hangzhou, 310058, China.
authors.forename: Zhibo
authors.initials: Z
authors.lastname: Wang
authors.affiliation: College of Environmental and Resource Sciences, Zhejiang University, Hangzhou, 310058, China.
authors.forename: Yixiang
authors.initials: Y
authors.lastname: Zhang
authors.affiliation: College of Environmental and Resource Sciences, Zhejiang University, Hangzhou, 310058, China.
authors.forename: Chunyan
authors.initials: C
authors.lastname: Zhu
authors.affiliation: College of Environmental and Resource Sciences, Zhejiang University, Hangzhou, 310058, China.
authors.forename: Limin
authors.initials: L
authors.lastname: Lin
authors.affiliation: College of Environmental and Resource Sciences, Zhejiang University, Hangzhou, 310058, China.
authors.forename: Lixian
authors.initials: L
authors.lastname: Xu
mesh_terms: D000383:Agriculture / Q000379:methods*; D004784:Environmental Monitoring; D008956:Models, Chemical; D009584:Nitrogen / Q000032:analysis*; D012275:Oryza; D010758:Phosphorus / Q000032:analysis*; D012621:Seasons; D012987:Soil; D014872:Water Movements; D014874:Water Pollutants, Chemical / Q000032:analysis*
chemical_list: D012987:Soil; D014874:Water Pollutants, Chemical; D010758:Phosphorus; D009584:Nitrogen
keywords: Nitrogen; No tillage; Nonpoint source pollution; Phosphorus; Rice; SWAT model