Is there an accepted* form of prayer for the prosperity of those keeping the shmitta year and if not – why not? My idea for a prayer would be along these lines which could be added into ברך עלינו:
"You have commanded us to keep the laws of the seventh year as it says in your Torah (Vayikro 25:4): ‘But in the seventh year, the land shall have a complete rest a Sabbath to the Lord; you shall not sow your field, nor shall you prune your vineyard.’
"and we are observing the laws of the seventh year that come from Your Torah both written and oral.
"Therefore we come before You to ask for Your blessing on all our life for You are the source of all blessing, …."
* (by halachic authority, use or printing in siddur or other)