@article {10.3844/ajessp.2016.102.121,
article_type = {journal},
title = {Spatial Analysis and Modeling the Nitrogen Flush after Rainfall Events at the Field Scale in SWAT},
author = {Haney, Elizabeth Brooke and Haney, Richard Lee and Arnold, Jeffrey George and White, Michael James and Srinivasan, Raghavan and Senseman, Scott Allen},
volume = {12},
number = {2},
year = {2016},
month = {Apr},
pages = {102-121},
doi = {10.3844/ajessp.2016.102.121},
url = {https://thescipub.com/abstract/ajessp.2016.102.121},
abstract = {Current nitrogen (N) models tend to neglect the contribution of the microbial population to the plant available N pool, resulting in an underestimation of yield and possible over or underestimation of N runoff from natural and agricultural landscapes. We used the measurement of microbial activity coupled with the measurement of their food source, water extractable nitrogen (N) and carbon (C), to add a flush of N after rainfall events in the Soil Water Assessment Tool (SWAT). Soil test data and spatial analysis of N mineralization values were used to: (1) Quantify spatial variation of water extractable organic and inorganic N, soil inorganic N and microbial activity; (2) develop a field scale model to determine N mineralization using updated soil testing methods for integration into the SWAT model; and (3) predict wheat yield. Simulation results indicate that yearly yield values and the variability of these yield values were consistently greater from the modified N model than from the SWAT model, as would be expected with the addition of N mineralization resulting from microbial activity. The spatial variability in yield results increased with the modified N model as compared to the SWAT model. The yield data resulting from the modified N model simulation were sensitive to soil nutrient values as well as variations in elevation. Temporal and climatic variability is accounted for by including a precipitation trigger for N mineralization. The equations used to model the complex biogeochemical N cycling relationships are elegant in their simplicity, yet capture the spatial complexity associated with their processes. The modified N model may be useful to regulators to help with the simulation of new conservation practices that include the effect of lower fertilizer inputs on nutrient runoff and pollution.},
journal = {American Journal of Environmental Sciences},
publisher = {Science Publications}
}