The subject of "turning the soil" is a curious one. For years, I double-dug my garden beds. So the soil was turned and loosened down to about 24 inches, using a square-edge spade and a turning fork. For growing vegetables, this allows denser planting, and dramatically higher yields. Doing it that way also requires more frequent watering that soaks down through the double-dug zone.
The double-dug gardening technique was promoted by the influential (and now out-of-print) book,
How to Grow More Vegetables, by John Jeavons, Ten Speed Press, Berkeley CA, 1974. It discussed and illustrated the principles of what was called Biodynamic/French Intensive gardening. A generation later, the same techniques were dubbed, "Square Foot Gardening." ["Square Foot" does roll off the tongue more easily than "Biodynamic/French Intensive".]
This works miracles for vegetable production, and I recommend it. In addition to the looser, more deeply tilled root zone provided by double-digging, the 5-foot-wide beds allow plantings that are far too dense to walk between, but easy access into the center-line of the bed from the side of the bed. All plants are spaced in a hexagonal pattern using the "within row" spacing of traditional planting methods, while ignoring the "between row" spacing.
Anywhere that you walk regularly (or on which you drive a piece of machinery or a plow horse) compacts the underlying soil, and restricts adequate root growth into that area. By planting in single rows, 1/2 to 2/3 of the soil area of a traditional garden is wasted in these compacted zones--the foot paths. With 5-foot-wide bed planting (and never walking on the bed), only the space between the individual beds is wasted.
Tobacco grows well in a double-dug bed, with each 5-foot-wide bed holding what may be considered 4 staggered rows of tobacco plants, for whatever the length of bed is dug. The width of spacing between the beds can be whatever you like, and it can be mowed lawn. Because the reach from the side of the bed to the center-line of the bed is only 30 inches, even more densely planted tobacco, such as Orientals with 6-12 inches between plants, can be easily reached for maintenance and harvest. I never get muddy boots from working my tobacco.
Blowdowns
On the negative side, the relatively shallow roots of tobacco (even of huge tobacco plants) never get below that 24" of double-dug, very loose dirt.
Tobacco in double-dug beds blows down more easily. I have no doubt about that. Although the softer soil makes standing the blow-downs back to a vertical position considerably easier than in denser soil, I would rather they just not blow down.
So, for my tobacco, I now manually till to only about 12 inches.
Weeds
I've actually tried a no-till method with tobacco. The plants seem to grow a little more slowly than in tilled soil. But weeds are fewer. Tilling soil brings long-dormant weed seeds toward the surface, allowing them to finally germinate. Some weed seeds can sit there, deep in the soil, for 5 years or more, then spring to life when the soil is tilled. That was one of the reasons for burning a freshly tilled field, prior to a final tilling-in of the resulting ash.
No-till does not seem to further reduce blow-downs--the only reason I even tried that method, but does seem to reduce tobacco productivity. In the end, the labor savings in weed reduction from no-till is not worth the decrease in production.
I don't hoe my weeds away. Hoeing (especially with a scraper, like a scuffle hoe) often removes the weeds above the surface, while leaving the deeper weed roots intact. The same weeds just grow back. And with tobacco roots being shallow and close to the surface, I can't really hoe deeply enough to extricate weed roots, once the tobacco plants are about 2 feet tall. So I manually pull the weeds, one by one. I wait for the day after a rain, so the soil is softer. I try to pull each weed with its roots still attached, while the weed is still a tiny baby. These never grow back.
Bob
