Is 10% a dream?

http://westernfarmpress.com/tree-nuts/walnut-industry-seeks-return-profitability
“The talk is walnut prices could be 20 to 30 cents (per pound) higher than last year.” That could peg prices in the 80 to 90 cent range.
Hanford grower Jeb Headrick predicts 5,500 pounds to 6,000 pounds from most of his ranches.
Beede said. “It costs about $2,000 an acre to farm walnuts. Growers risk a lot of money.”

If you split the profit, say 6000 * .90 - 2000 = 3400 with a renter, then $1,700/per arce/per year.

Let's say the purchase price is 10,000/per arce w/o trees, grows the tree, ...

let's say the purchase price is 20,000/per arce w trees, then ...  

UC davids has more detailed data.