Nitrogen transport and transformation in the saturated-unsaturated zone under recharge, runoff, and discharge conditions

2016 ◽  
Vol 23 (9) ◽  
pp. 8741-8748 ◽  
Author(s):  
Zhifei Ma ◽  
Xinying Lian ◽  
Yonghai Jiang ◽  
Fanhua Meng ◽  
Beidou Xi ◽  
...  
Keyword(s):  
Unsaturated Zone ◽  
Nitrogen Transport ◽  
Transport And Transformation

scholarly journals Numerical Analysis of the Transport and Fate of Nitrate in the Soil and Nitrate Leaching to Drains

2001 ◽  
Vol 1 ◽  
pp. 170-180 ◽  
Author(s):  
Alaa El-Sadek ◽  
Mona Radwan ◽  
Jan Feyen
Keyword(s):  
Nitrate Leaching ◽  
Initial Conditions ◽  
Continuous Cropping ◽  
Nitrogen Transport ◽  
State Variables ◽  
Nitrogen Application ◽  
Transport And Transformation ◽  
Bottom Boundary Condition ◽  
Rainfall Depth ◽  
Simulation Results

In this study, the transport and fate of nitrate within the soil profile and nitrate leaching to drains were analyzed by comparing historic field data with the simulation results of the DRAINMOD model. The nitrogen version of DRAINMOD was used to simulate the performance of the nitrogen transport and transformation of the Hooibeekhoeve experiment, situated in the sandy region of the Kempen (Belgium) and conducted for a 30-year (1969–1998) period. In the analysis, a continuous cropping with maize was assumed. Comparisons between experimentally measured and simulated state variables indicate that the nitrate concentrations in the soil and nitrate leaching to drains are controlled by the fertilizer practice, the initial conditions, and the rainfall depth and distribution. Furthermore, the study reveals that the model used gives a fair description of the nitrogen dynamics in the soil and subsurface drainage at field scale. From the comparative analysis between experimental data and simulation results it can also be concluded that the model after calibration is a useful tool to optimize as a function of the combination “climate-crop-soil-bottom boundary condition” the nitrogen application strategy resulting in an acceptable level of nitrate leaching for the environment.

scholarly journals Understanding nitrogen transport in the unsaturated zone with fluctuations in groundwater depth

2021 ◽  
Author(s):  
Jianmin Bian ◽  
Qian Wang ◽  
Siyu Nie ◽  
Hanli Wan ◽  
Juanjuan Wu
Keyword(s):  
Support Vector Machine ◽  
Unsaturated Zone ◽  
Prediction Models ◽  
Groundwater Depth ◽  
Support Vector ◽  
Nitrogen Transport ◽  
Irrigation Area ◽  
Leaching Loss ◽  
The Relationship ◽  
Hydrus 1D

Abstract Fluctuations in groundwater depth play an important role and are often overlooked when considering the transport of nitrogen in the unsaturated zone. To evaluate directly the variation of nitrogen transport due to fluctuations in groundwater depth, the prediction model of groundwater depth and nitrogen transport were combined and applied by least squares support vector machine and Hydrus-1D in the western irrigation area of Jilin in China. The calibration and testing results showed the prediction models were reliable. Considering different groundwater depth, the concentration of nitrogen was affected significantly with a groundwater depth of 3.42–1.71 m, while it was not affected with groundwater depth of 5.48–6.47 m. The total leaching loss of nitrogen gradually increased with the continuous decrease of groundwater depth. Furthermore, the limited groundwater depth of 1.7 m was found to reduce the risk of nitrogen pollution. This paper systematically analyzes the relationship between groundwater depth and nitrogen transport to form appropriate agriculture strategies.

Aspects of Nitrogen Transport and Transformation in Headwater Streams

1981 ◽  
pp. 113-139 ◽  
Author(s):  
N. K. Kaushik ◽  
J. B. Robinson ◽  
W. N. Stammers ◽  
H. R. Whiteley
Keyword(s):  
Headwater Streams ◽  
Nitrogen Transport ◽  
Transport And Transformation
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