I am thinking of a similar route, as a data scientist i am eager to know what graduate level courses would you recommend ? Especially for agriculture in cold climate (Canada )
That said, if you want a quick primer, "Crop ecology: productivity and management in agricultural systems" is a good primer on most of the basic ecological systems in agriculture. I've read it cover to cover many times.
However, you don't need a grad-level education to farm (believe me, I have been reminded this endlessly) - this is more for people doing research. For applied/actionable specifics for cold climates, your best friend is going to be local crop-extension services (in the US, most land-grants run an extension service). They will have tested techniques for your area and will be able to point you to good resources for farmers, not people researching agriculture.