QSWAT+ Irrigation and Fertilizer Not Applied Despite Crop Yield Output

[Luqman Hakim]

Hello everyone,

I am working on a QSWAT+ 3.1.2 and SWAT+ Editor 3.1.4 model to simulate the impact of rice paddy fertilizer runoff on river water quality. I have encountered two issues that I hope you can help me with:

1. Irrigation and Fertilizer Not Being Applied to Paddy Fields

I have configured both fertilizer application and irrigation schedules (both manual and automatic) through the Schedule Management interface and assigned these schedules to rice land use in the Land Use Management table. However, the final results show no irrigation or fertilizer being applied to the paddy field HRUs.

Interestingly, when I check the crop yield output file, there are yield values present. How is it possible for crop yield to be generated without any irrigation or fertilizer uptake by the plants?

I have verified the following:

• The management schedule is properly assigned to rice_lum in the Land Use Management table
• Operations include till, plant, irrigation (irrm), and fertilizer (fert) with appropriate timing
• The plant database contains rice parameters
• The fertilizer database includes the custom fertilizers I'm using

Could there be an issue with how the operations are being read or executed? What should I check in the output files (output.hru or .mgt files) to diagnose this problem?

2. Efficient Method for Creating and Editing Management Schedules

Currently, I am inputting operations one by one in the Schedule Management interface, which is very time-consuming. I attempted to export the schedule, edit it manually in Notepad, and re-import it, but SWAT Editor returns an error. I also tried opening the .sch file in MS Access and MS Excel, but the file cannot be read properly.

Is there any software or tool that can be used to create and edit SWAT management schedules more efficiently? Or is there a specific format/template I should follow when editing schedule files externally?

Any guidance would be greatly appreciated!

Thank you in advance for your help.

Regards,
Luqman H.