Establishing a supply curve in rice retail and wholesale, feasibility study?

Hey there :)

I am a student conducting a feasibility study and I am currently concerned in establishing the demand and supply curves. Now, I have gathered data regarding the demands so I am fine with it because my rice business only covers and caters a particular place in the city. The supply curve is now my problem, where do I start? I mean how can I have the information in order to draw the supply curve?

By the way, it was suggested that I procure the information from a government office but then what it has is the whole production of our city and my consumer coverage is just a little town in the city.How can it be appropriate? Thanks in advance.