No-tillage effects on N and P exports across a rice-planted watershed.
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.
['Liang|Xinqiang|X|', 'Wang|Zhibo|Z|', 'Zhang|Yixiang|Y|', 'Zhu|Chunyan|C|', 'Lin|Limin|L|', 'Xu|Lixian|L|']
D000383:Agriculture D004784:Environmental Monitoring D008956:Models, Chemical D009584:Nitrogen D012275:Oryza D010758:Phosphorus D012621:Seasons D012987:Soil D014872:Water Movements D014874:Water Pollutants, Chemical
No tillage Nitrogen Phosphorus Rice Nonpoint source pollution SWAT model