How to disable casting shadows from landscape?

Hello.

I am currently making a large field that uses landscape.

The landscape is being used only for texture blending to draw ground such as road.

My landscape is fully flat, so I want to turn off the “Cast Shadow” option for performance.

But I could not find the option in the Landscape Detail.

My game is running on Mobile, so the performance optimization is very important.

Please let me know how do I can achieve this.

Thanks.

Did you figure out how to do this? I need a similar setup.