Hey Frank,
Like everyone else, I hope you have the best of luck.
Also like everyone else, be VERY careful and please limit your liability.
A solid written contract is a good start as if the help of an attorney so versed.
I have leased ground before, and some of the key provisions is that both the parties (you and landowner) limit access to the property. Make sure you have expressed rights to do what you must, harvest, spray, cut brush and small trees or deadwood, etc.
Another provision I've used is to set the term yearly from July 1st. Then, upon written notification of the desire to terminate the agreement by the end of June, you have until the end of December one year later (18 months) to remove any harvestable plants. Don't forget to specify that you are the owner of the roots and that your partner's participation is limited to the ground in which they grow. Therefore, you may want to include something about reimbursement should the agreement be ended and some of the plants (many of them in reality) be legally not harvestable for some length of time because of legal requirements in the harvesting of wild or wild simulated ginseng.
Don't forget to include some sort of survivorship clause that will bind heirs and assigns and subsequent owners if he dies or decides to sell the land.
That will get you started. Oh, and I would try to tie up the ground for a minimum of 15 years. Most wild sim is not ready to harvest at 7 or 8 years as it turns out.
