Improving irrigation management in wheat farms through the combined use of the AquaCrop and WinSRFR models
Received date: 2024-06-30
Revised date: 2024-11-09
Accepted date: 2024-11-27
Online published: 2025-08-12
Arash TAFTEH , Mohammad R EMDAD , Azadeh SEDAGHAT . [J]. Journal of Arid Land, 2025 , 17(2) : 245 -258 . DOI: 10.1007/s40333-025-0005-y
Water is essential for agricultural production; however, climate change has exacerbated drought and water stress in arid and semi-arid areas such as Iran. Despite these challenges, irrigation water efficiency remains low, and current water management schemes are inadequate. Consequently, Iranian crops suffer from low water productivity, highlighting the urgent need for enhanced productivity and improved water management strategies. In this study, we investigated irrigation management conditions in the Hamidiyeh farm, Khuzestan Province, Iran and used the calibrated AquaCrop and WinSRFR (a surface irrigation simulation model) models to reflect these conditions. Subsequently, we examined different management scenarios using each model and evaluated the results from the second year. The findings demonstrated that combining simulation of the AquaCrop and WinSRFR models was highly effective and could be employed for irrigation management in the field. The AquaCrop model accurately simulated wheat yield in the first year, being 2.6 t/hm2, which closely aligned with the measured yield of 3.0 t/hm2. Additionally, using the WinSRFR model to adjust the length of existing borders from 200 to 180 m resulted in a 45.0% increase in efficiency during the second year. To enhance water use efficiency in the field, we recommended adopting borders with a length of 180 m, a width of 10 m, and a flow rate of 15 to 18 L/s. The AquaCrop and WinSRFR models accurately predicted border irrigation conditions, achieving the highest water use efficiency at a flow rate of 18 L/s. Combining these models increased farmers' average water consumption efficiency from 0.30 to 0.99 kg/m³ in the second year. Therefore, the results obtained from the AquaCrop and WinSRFR models are within a reasonable range and consistent with international recommendations. This adjustment is projected to improve the water use efficiency in the field by approximately 45.0% when utilizing the border irrigation method. Therefore, integrating these two models can provide comprehensive management solutions for regional farmers.
Key words: AquaCrop; crop modeling; WinSRFR; water management; water use efficiency
Fig. 1 Location of the study area (a) and farms (b) in the Hamidiyeh region, Iran. D, sluice gate. |
Table 1 Mean soil physical and chemical properties |
| Depth (cm) | Soil texture | PWP (%) | FC (%) | SOC (%) | pH | SAR | EC (dS/m) | BD (g/cm3) |
|---|---|---|---|---|---|---|---|---|
| 0-30 | Clay loam | 19 | 31.9 | 0.5 | 7.8 | 4.3 | 4.5 | 1.48 |
| 30-60 | Clay loam | 23 | 36.4 | 0.3 | 7.8 | 5.1 | 5.0 | 1.53 |
Note: PWP, permanent wilting point; FC, field capacity; SOC, soil organic carbon; SAR, sodium absorption ratio; EC, electrical conductivity; BD, bulk density. |
Fig. 2 Reference evapotranspiration (ET0) and precipitation (P) in wheat-growing season during the two years |
Fig. 3 Changes in the length of water advancing front in the soil of the three farms |
Fig. 4 Process of combining the results of the AquaCrop and WinSRFR models for farm water management |
Table 2 Variation of simulated wheat yield with irrigation events using the Aquacrop model |
| Index | Farm 1 | Farm 2 | Farm 3 | |||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| 3 | 4 | 5 | 6 | 3 | 4 | 5 | 6 | 3 | 4 | 5 | 6 | |
| Consumed water (kg/m3) | 5800 | 7600 | 9400 | 11,200 | 5800 | 7600 | 9400 | 11,200 | 5800 | 7600 | 9400 | 11,200 |
| ET (mm) | 234 | 258 | 270 | 297 | 272 | 309 | 323 | 333 | 267 | 302 | 329 | 328 |
| Total yield (t/hm2) | 4.7 | 5.8 | 5.8 | 6.0 | 6.2 | 7.2 | 7.2 | 7.2 | 5.6 | 6.6 | 6.7 | 6.6 |
| Grain yield (t/hm2) | 1.9 | 2.4 | 2.4 | 2.5 | 2.5 | 2.9 | 2.9 | 2.9 | 2.2 | 2.6 | 2.6 | 2.6 |
| WP (kg/m3) | 0.33 | 0.31 | 0.26 | 0.22 | 0.43 | 0.38 | 0.31 | 0.26 | 0.38 | 0.34 | 0.28 | 0.23 |
Note: 3-6 mean the irrigation events; ET, evapotranspiration; WP, water productivity. |
Fig. 5 Comparison between simulated and measured grain yields by the AquaCrop model. NRMSE, normalized root mean square error. |
Table 3 Comparison between measured and simulated application efficiencies in the first year |
| Farm | Irrigation | Stage | Discharge (L/s) | Water depth (mm) | Net water depth (mm) | Measured application efficiency (%) | Simulated application efficiency (%) | Standard error (%) |
|---|---|---|---|---|---|---|---|---|
| 1 | 1 | Initial | 19 | 161 | 50 | 31.0 | 28.0 | 6.9 |
| 2 | Development | 17 | 185 | 50 | 27.0 | 25.0 | 7.4 | |
| 3 | Mid-growth | 20 | 172 | 50 | 29.0 | 26.0 | 10.3 | |
| 2 | 1 | Initial | 18 | 156 | 50 | 32.0 | 30.0 | 6.2 |
| 2 | Development | 17 | 160 | 50 | 31.0 | 28.0 | 9.6 | |
| 3 | Mid-growth | 19 | 188 | 50 | 26.0 | 24.0 | 7.6 | |
| 3 | 1 | Initial | 18 | 180 | 50 | 28.0 | 25.0 | 10.7 |
| 2 | Development | 19 | 165 | 50 | 30.0 | 27.0 | 10.0 | |
| 3 | Mid-growth | 19 | 160 | 50 | 31.0 | 28.0 | 9.6 |
Fig. 6 WinSRFR simulation result under different border widths with a 0.2% slope. (a), 8 m width; (b), 10 m width; (c), 12 m width. |
Fig. 7 Water use efficiency under different widths and discharges with a border length of 180 m |
Table 4 Range of water productivity (WP) measured in the second year |
| Farm | Replication | Stage | Flow (L/s) | Depth of water (mm) | Net depth of water (mm) | Measured water application efficiency (%) | Simulated water application efficiency (%) | Standard error (%) | WP (kg/m3) |
|---|---|---|---|---|---|---|---|---|---|
| Farm 1 | 1 | Initial | 18 | 110 | 50 | 45.0 | 40.0 | 11.0 | 0.97 |
| 2 | Development | 20 | 115 | 50 | 43.0 | 37.0 | 14.0 | 0.81 | |
| 3 | Mid-growth | 22 | 120 | 50 | 41.0 | 35.0 | 15.0 | 0.97 | |
| Farm 2 | 1 | Initial | 18 | 114 | 50 | 44.0 | 40.0 | 9.0 | 1.01 |
| 2 | Development | 20 | 142 | 50 | 35.0 | 37.0 | 6.0 | 0.80 | |
| 3 | Mid-growth | 22 | 152 | 50 | 33.0 | 35.0 | 6.0 | 0.75 | |
| Farm 3 | 1 | Initial | 18 | 108 | 50 | 46.0 | 40.0 | 13.0 | 0.98 |
| 2 | Development | 20 | 125 | 50 | 40.0 | 37.0 | 8.0 | 0.89 | |
| 3 | Mid-growth | 22 | 132 | 50 | 38.0 | 35.0 | 8.0 | 0.83 | |
| Average | 1 | Initial | 18 | 111 | 50 | 45.0 | 40.0 | 11.0 | 0.99 |
| 2 | Development | 20 | 127 | 50 | 39.0 | 37.0 | 9.0 | 0.83 | |
| 3 | Mid-growth | 22 | 135 | 50 | 37.0 | 35.0 | 10.0 | 0.85 |
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