The title of my research is the contribution of agroforestry in soil fertility to small farmers. I'm using mixed-method research I don't know what should I do in making the theoretical framework. Sorry if I'm not good in English.
Yes, it is possible to use one theory for a theoretical framework. However, most theoretical frameworks use multiple theories or concepts to provide a comprehensive understanding of a particular problem or research question. It is also important to consider how the theory or theories chosen to interact with one another and how the theoretical framework can be applied to the research problem.