John, Actually, what we've already designed is that when you record the harvest of the crop (in the Farming box) you will have a button to click on to pull total yield over from your yield map. This will allow you to select the layer that has the yield data and have the total bushels filled into the Farming box for you. The result is that you will have the total bushels from your yield map in Farm Fund$ as well as in the notations for each field. This is all a part of "Profit Mapping" that will be added in this Fall's Fund$/Site upgrade (to be released in September).
Additionally, we are planning a future release (probably this Winter) that will include the type of spreadsheet report summary that you referred to.