Thanks for your response. The references cited all seem to be for veggies in a short rotation. They cite crop rotation which is a great principle, as well as cultivation. On a 8 to 10 year rotational cycle neither of those methods are practical in Christmas trees.
I have an acquaintance who provides the organic milk for the Wegman's chain milking thousands of Holsteins and growing corn, hay, and beans for feed. I haven't leaned on him for what he does, and while corn and beans are 1 year rotation crops, he probably gets a few years out of alfalfa. I also have the feeling that it's possible to be certified organic while still using moderate amounts of "approved" chemicals.
Years ago my son worked at the landscape plant wholesale nursery primarily hoeing for 8 or 10 hours a day. A few days later that field got sprayed to keep weeds in check. (Yes, he was developing some NFL forearms.)
FWIW I don't use any chemicals or petro based fertilizers anywhere near my home or vegetable garden. I really am searching for a practical approach to weed management. As I stated earlier I really don't enjoy pumping this **** into our already ill atmosphere.
What I have seen is well intentioned folks attempting organic Christmas trees and after 4 or 5 years they realize they have a tremendous crop of weeds and brush with some ratty trees thrown in.That is a lot of wasted time and money. I haven't seen anyone succeed. There are a few studies out there from UNC and Penn State really dissing attempts at Organic trees.
I didn't realize you were growing Christmas trees; not row crops. Some of the methods may still work. I was intrigued by the "flaming" method. Seems like that might have some promise. Sometimes we are too "all or nothing"; perhaps a goal of *reducing* chemical usage is more attainable? I don't know if grass is okay, or if you need the soil bare between your rows, but what about a cover crop? This method of restoring a lawn: in early spring plant annual rye (if you don't want the grass to persist) or a contractor's mix (if you want it to stay year after year); it shoots up fast and outcompetes almost any weed you care to name. Of course everything gets expensive on 15 miles of rows.
As for the home garden, that one's pretty easy. At the end of the growing season, scoop all the surface soil into a large pile along with some shredded lawn waste for composting, which obviously kills weeds and pests in the soil. You can then cover the bare garden with almost anything--newspapers, plastic sheeting, etc.--to keep it weed free if you need to. Then in late spring re-spread the topsoil. If you only use half your garden each season and let the other half lay fallow, your compost will have a whole year to "cook."
To keep weeds under control during the garden season, I don't use rows because they provide a ton of space for weeds to grow in between your veggies. I plant things in sections that are small enough for me to lean over and tend the middle (around 4x4') and I also plant the seeds much closer together than recommended on the seed pack. The result is a dense stand of veggies that shades out most of the weeds (and also requires little to no watering). In the narrow paths between each section, I dump some cheap mulch which helps hold moisture in the soil, makes for nice paths for tending the garden, puts a damper on the weeds, and any weeds that do pop up, lift out very easily.
I'm an experimental gardener.

I'm always trying new methods to try to get better results with less effort. Next spring I want to try the old Indian method for low maintenance gardening: in one hole plant a corn seed, a climbing bean seed, and a squash seed. The corn stalk is for the bean to climb, and the squash shades out any weeds and keeps the soil moist.
I wonder what would happen if you planted squash in your rows. ? Squash will reseed itself every year if you leave the fruit.
