Holland transplanter is THE NAME in the US. Not cheap new, they show up on craigslist occasionally for good prices. A zillion options based on how you are planting (bare
root, plugs, tubs, etc.) and what kind of ground (no-till to fully tilled market garden soil).
http://www.transplanter.com/
I am in the process of building one based on my basic subsoiler, but for now I run the subsoiler on contour for the row of
trees then plant by hand. The subsoil slice makes it much easier.
"You must be the change you want to see in the world." "First they ignore you, then they laugh at you, then they fight you, then you win." --Mahatma Gandhi
"Preach the Gospel always, and if necessary, use words." --Francis of Assisi.
"Family farms work when the whole family works the farm." -- Adam Klaus