I agree with Jennifer and Kaile that creating a compost bin! I added an article (See the APA citation and link below) into my library about how to create garden spaces in schools with little money and space. The authors provide insights into implementing a vermicomposting center in coordination with cafeteria administration. If your school does not already have a garden or green space, this might be a great way to implement one while combating food waste in the cafeteria at the same time! Food scraps from the cafeteria would be necessary for maintenance of the compost.
Overall, students are not only learning to take responsibilty for the garden but can also learn about the varity of science phenonemon that occur in a garden such as photosynthesis, the water cycle, and decomposition, all with the aid of their cafeteria scraps!
Quigley, C., Tlusty, T., Hendrix, C., & Foster, A. (2015). No Space? Little Money? No Garden? Not So Fast! Science Scope, 038 (05), 21-25. Retrieved from https://s3.amazonaws.com/nstacontent/ss1505_40.pdf?AWSAccessKeyId=AKIAIMRSQAV7P6X4QIKQ&Expires=1573183974&Signature=uyYI%2fHGrWIE0U5ivt7vE2f%2bi0X4%3d