There is no single recipe to determine the right cover crop mix for a particular field, much less an entire farm. You need to know each field, set goals and set a budget that makes sense. Are the primary concerns to retain and build nutrient levels for the coming crop, managing moisture, compaction or simply building soil health? Is grazing a potential income source? Which cover crops match the post-harvest-to-freeze interval in your area? Do you want to deal with pre-plant burn-down or do you prefer letting winterkill do the job?