Anyone know of a good, economical means of killing stumps of freshly cut trees? Herbicide?

Also, I will need to remove the stumps before they decay therefore, is a tractor the only way to go?

If you can get some Tordon to paint the freshly cut trees it will get them, but it is illegal in some states. Call your local farm supply and see what they have available. If you are going to dig them, why use aherbicide? I wouldn't even try a farm tractor. An excavator is the best option to remove stumps.

an old woman i know used to drill holes in the stump and pour soured milk down the holes to kill them.

I'm using a mixture of 50% glyphosate and 50% water to treat stumps for a conservation program I enrolled in. It seems to do OK, but I may have missed spraying the stumps that sprouted back, I'm just not sure. The glyphosate is 41% solution. If you don't want the roots and stumps sprouting you must spray them, except for some evergreen trees.

Glysophate (Round-up) will work well but as stated you must use it in high concentration.

A product called "Cross Bow" ( a 2-4-5T generation, I think) is a brush killer where glysophate is a grass killer) and can be applied at much lower concentrations. Watch out for "Tordon" as even the "new model" has some leaching problems. Not that is not by far the best brush killer out there next to Remedy and Valpar.

Several of these require applicator certification to purchase.

Buy Tordon RTU....its not restricted use, is made for only one purpose...treating cut stumps. It IS NOT the same as Tordon 22K.

The roundup treatments are poor performers and by the time you find out it didnt work you have a mess...

Crossbow is not 2,4-5 T at all Crossbow is tryclopyr or Remedy/Garlon plus 2, 4-D. It is not a good stump treatment. It is a foliar brush killer.

If you can get your hands on some kerosene, it works better than anything I've ever used.

Just get an excavator....

I know a great way my grandfather told me about that his father used. Just take a bag of salt and pour on the stump. When it rains the salt soaks into the stump.(be sure to use plenty of salt) When the salt soaks in animals (mostly deer) will come to get the salt and eat away the stump until nothing is left. Butif the stump isin your front yard where deer most likely dont want to be then this probably wont work.

The way you are talking though an excavator probably is best.