|Crop||Yield per acre||Protein Content||Protein Yield|
All yields are close, except the incredible Comfrey (are those numbers real?). The numbers are for Russian Comfrey, which should grow well in the PNW. It is a heavy nitrogen feeder. It is a perennial that will produce at full yield starting the 3rd year, once the deep tap roots are well established. It can be cut every 5 weeks during the season. It is also difficult to eradicate once established. One option would be to plant it directly inside the chicken run, and protect each plant, then let the chickens feed on one plant at a time.
I may plant at leat 5 plants in the chicken run next year, and protect them the first year to allow them to grow to maturity, then use them as feed supplement.
Aside from Comfrey, we can see that protein yield per acre is a lot more constant that whole yield, and should actually be the main criteria for selecting a crop. Corn, barley and peas seem to be the winners, while sunflower can still be planted as an ornamental while providing some additional proteins.