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| Titel |
Validation and application of a two-dimensional model to simulate soil salt
transport under mulched drip irrigation |
| VerfasserIn |
Huiqing Jiao, Chengyi Zhao, Yu Sheng, Yan Chen, Jianchu Shi, Baoguo Li |
| Konferenz |
EGU General Assembly 2017
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| Medientyp |
Artikel
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| Sprache |
en
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 19 (2017) |
| Datensatznummer |
250143496
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| Publikation (Nr.) |
 EGU/EGU2017-7220.pdf |
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| Zusammenfassung |
| Water shortage and soil salinization increasingly become the main constraints for sustainable
development of agriculture in Southern Xinjiang, China. Mulched drip irrigation, as a
high-efficient water-saving irrigation method, has been widely applied in Southern
Xinjiang for cotton production. In order to analyze the reasonability of describing the
three-dimensional soil water and salt transport processes under mulched drip irrigation with a
relatively simple two-dimensional model, a field experiment was conducted from 2007 to
2015 at Aksu of Southern Xinjiang, and soil water and salt transport processes were
simulated through the three-dimensional and two-dimensional models based on COMSOL.
Obvious differences were found between three-dimensional and two-dimensional
simulations for soil water flow within the early 12 h of irrigation event and for
soil salt transport in the area within 15 cm away from drip tubes during the whole
irrigation event. The soil water and salt contents simulated by the two-dimensional
model, however, agreed well with the mean values between two adjacent emitters
simulated by the three-dimensional model, and also coincided with the measurements as
corresponding RMSE less than 0.037 cm3 cm−3 and 1.80 g kg−1, indicating that the
two-dimensional model was reliable for field irrigation management. Subsequently, the
two-dimensional model was applied to simulate the dynamics of soil salinity for five
numerical situations and for a widely adopted irrigation pattern in Southern Xinjiang
(about 350 mm through mulched drip irrigation during growing season of cotton and
total 400 mm through flooding irrigations before sowing and after harvesting). The
simulation results indicated that the contribution of transpiration to salt accumulation
in root layer was about 75% under mulched drip irrigation. Moreover, flooding
irrigations before sowing and after harvesting were of great importance for salt
leaching of arable layer, especially in bare strip where drip irrigation water hardly
reached, and thus providing suitable root zone environment for cotton. Nevertheless,
flooding irrigation should be further optimized to enhance water use efficiency. |
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