hairy vetch I

the hairy vetch in my back yard was blooming in early june ( top photo taken june fifth ) and in early july those blooms have become seed pods...there are s multitude of them out there...some are green yet and some are mature enough to harvest and i have begun to bring them in...well nodulated hairy vetch can add sixty to one hundred twenty pounds of nitrogen to soil per acre ( university of wisconsin extension ) with fall planted vetch that is turned under in spring producing less...this suggests that to obtain maximum benefit from the green manure that beds should be planted in the autumn with vetch, left to overwinter, and then the bed should be left to the vetch for the next season with winter rye planted the following autumn to act as a reservoir..seeds could be harvested in the summer as well and the entire bed turned under the second spring...basically a two year process of fertility building and addition of organic matter...since i planted this vetch last summer and have let it mature to collect seed i believe i will continue the process with another planting of winter rye in the bed and then will turn the plant matter under in spring 2015 and utilize the bed for a planting of a vegetable we are growing this year...we can record harvest data from this season and compare results with the bed i will plant in my yard next spring...at least a rough idea of the value of this plant as a green manure...the resources for this project are outside my door and having gone this deep into the process i can't give a good reason not to proceed...always room for another project...particularly as one is winding down after five years.