GIS/EM4 - Simulation of soil water and nitrogen behaviors under agricultural field in the North China Plain

Simulation of soil water and nitrogen behaviors under agricultural field in the North China Plain

GIS/EM4 No. 40

Yuanfang Huang
Yunzhu Li
Baoguo Li
Deli Chen

Abstract

The North China Plain was selected as the research region of this paper. After simplified the parameters of crop growth and development, regional soil and meteorology, a soil water-nitrogen-heat join model was employed to simulate the regional water and nitrogen behaviors, combined with GIS method. Under the treatment of mediate level of water and nitrogen, the simulating results indicated that water use efficiency (WUE) was obviously different between different hydrologic year types, high in dry year, low in wet year. However, the similar regularity of nitrogen use efficiency (NUE) was not so obviously. The distributions of WUE and NUE in the North China Plain were much depended upon the soil and meteorological conditions.

Keywords

Water, nitrogen, simulation, model, agricultural field, the North China Plain, GIS.

Introduction

Processes simulation models of soil water and nitrogen were widely developed (Addiscott 1993). Some soil water-nitrogen process models have been coupled with GIS to study regional events (Shaffer, Wylie, Hall, 1995, Wu, Ward, Workman, 1996). The strategies of the integration of GIS and models can be classified as three forms on the coupling tight degree (Tim, 1996). This paper tried the loose integrity of GIS and process model to study the regional distribution of water use efficiency (WUE) and nitrogen use efficiency (NUE) under different hydrologic years.

Approach

Based upon data of the Chinese Second National General Soil Survey, a simplified distribution map of soil types in the North China Plain was obtained with GIS, see Figure 1. The cropping system was fixed as winter wheat and summer maize rotation system supplied with mediate quantity irrigation and nitrogen fertilizer. The soil water-nitrogen-heat joint model used in this paper has been established and verified by the field experimental data (Huang, Li, Lu, 1996). The climatic data were obtained from seven meteorological stations. WUE and NUE are grain yield obtained per unit water consumed (kg grain m^-3 water) and per unit nitrogen consumed (kg grain kg^-1 N), respectively.

Findings

Figure 2, 3 and 4 were the simulated results of WUE, which indicated the distributions of WUE under different hydrologic years are obviously different, higher in dry year but lower in wet year. Tthe figures of the distribution of NUE were not listed here. The percentage of area with NUE larger than 15.0kg grain kg^-1 N under dry, mediate and wet hydrologic year was 68.48%, 60.33% and 52.18%, respectively. These indicated the distribution of NUE is similar to WUE, but not so obviously.

Conclusion

The results indicated that the distributions of WUE and NUE in the North China Plain were much depended upon the soil and meteorological conditions.

References used

Addiscott TM. 1993. Simulation modelling and soil behavior. Geoderma, 60:15-40.

Huang Y, Li Y and Lu J. 1996. Simulation of soil nitrogen transport under field conditions. Journal of Hydraulic Engineering, 6: 9-23. (in Chinese)

Shaffer MJ, Wylie BK and Hall MD. 1995. Identification and mitigation of nitrate leaching hot spots using NLEAP-GIS technology. J. Contam. Hydrol., 20:253-263.

Tim US. 1996. Coupling vadose zone models with GIS: Emerging trends and potential bottlenecks. J. Environ. Qual. 25: 535-544.

Wu QJ, Ward AD and Workman SR. 1996. Using GIS in simulation of nitrate leaching from heterogeneous unsaturated soils. J of Environ Qual., 25, 526-534.

Authors

Yuanfang Huang, Associate Professor, Deputy Head, Department of Soil and Water Sciences
China Agricultural University, Beijing 100094, P. R. China.
Email: yfhuang@china.com, Tel: +86-10-62892504, Fax: +86-10-62892504.

Yunzhu Li, Professor, Department of Soil and Water Sciences
China Agricultural University, Beijing 100094, P. R. China.
Email: shiyc@public.bta.net.cn, Tel: +86-10-62892959, Fax: +86-10-62892513.

Baoguo Li, Professor, Head, Department of Soil and Water Sciences
China Agricultural University, Beijing 100094, P. R. China.
Email: libg@mail.cau.edu.cn, Tel: +86-10-62892850, Fax: +86-10-62892513.

Deli Chen, Senior Research Fellow, Institute of Land and Food Resources
The University of Melbourne, Parkville 3052, Australia.
Email: d.chen@landfood.unimelb.edu.au, Tel: +61-3-83448148, Fax: +61-3-83445570.