Characteristics and simplified model of film slit irrigation

ABSTRACT

Research on the factors affecting the characteristics of film slit irrigation has not received sufficient attention, although this is a wide-adopted irrigation technology. Infiltration modelling based on fewer factors deserves priority in the field studies. A laboratory theoretical study was conducted to investigate the simulated effects of SWMS-2D (simulating water movement through soil in two-dimensional) on soil moisture and cumulative infiltration of film slit irrigation. Error analyses indicated that SWMS-2D was suitable for infiltration simulation. Besides, SWMS-2D was applied to investigate the cumulative infiltration affected by soil texture, initial soil moisture, irrigation water depth, soil structure, opening ratio (ρ), and film slit width (d) and spacing. Results showed that for a certain soil, initial soil moisture and irrigation water depth had the poorest effects, whereas ρ and d had the strongest effects on cumulative infiltration among the 6 influencing factors. Furthermore, a simplified model with only ρ and d was proposed and verified by 3 soil types, which indicated that the proposed double-factor model can be employed for cumulative infiltration estimation under film slit irrigation, due to small mean absolute error of 1.03–3.13 mm, root mean square error of 1.24–3.80 mm, and high Nash-Sutcliffe coefficient around 1.0.

KEYWORDS:

• Film slit irrigation
• numerical simulation
• SWMS-2D
• simplified model

Acknowledgments

This research was jointly supported by grant of National Natural Science Foundation of China (No. 51279167 and No. 51579205), Special Fund for Agro–scientific Research in the Public Interest (No. 201503124) and Specialized Research Fund for the Doctoral Program of Higher Education of China (No. 20120204110023). A special and sincere thanks to the Key Laboratory of Agricultural Soil and Water Engineering in Arid and Semiarid Areas, Ministry of Education for the support for the experiments.

Author Contributions

Xiaoyi Ma and Haiyan Fan conceived and designed the experiments; Yibo Li and Haiyan Fan performed the experiments; Yibo Li, Ye Liu and Lei Wu analyzed the data; Xiaoyi Ma contributed reagents/materials/analysis tools; Yibo Li wrote the paper; and Xiaoyi Ma and Lei Wu revised the paper.

Disclosure statement

No potential conflict of interest was reported by the authors.

Additional information

Funding

This work was supported by the National Natural Science Foundation of China [51279167,51579205];Specialized Research Fund for the Doctoral Program of Higher Education of China [20120204110023];Special Fund for Agro-scientific Research in the Public Interest of China [201503124].