Before you pull out the ol' rototiller this spring, pause a moment to reflect on Jethro Tull.
No, not that one.
Tull revolutionized British agriculture in the 18th century with his inventions: a seed drill that ensured uniform planting of seeds, and a horse-drawn hoe. His machines solved challenges of his day – erratic germination of field crops, competition from weeds- and their design still influences modern agriculture. Buoyed by the success of his methods, he expounded in Horse-hoeing Husbandry his belief that best practices include pulverizing the soil to release nutrients, and withholding manure and other organic matter .
Turns out, his theories weren't quite as useful as his patents. We know now that adding organic matter improves soil structure, supports a diverse soil ecology, and supplies plant nutrients. And, that repeatedly tearing up the soil through deep plowing can destroy soil health, leading to the kind of conditions that created the tragic "Dust Bowl" of the 1930s.
By now, you might be looking at that rototiller in the back of the shed with some suspicion, but what to do about preparing the garden this spring? If you are lucky enough to be able to time travel, you will have planted a winter-kill cover crop (I use oats for this) in October, or will have covered your beds with a mulch of straw, grass clippings, or leaves. Now you simply pull back the mulch and sow seeds, replacing the mulch after the seeds have sprouted. For the cover cropped areas, you can trim the stalks and plant transplants directly into the bed, relying on the remaining residue to retain water and suppress weeds.
On bare beds, a few passes with a sharp scuffle hoe or stirrup hoe to sever young weeds from their roots, followed by smoothing with a steel rake, might be all you need if the weeds are mostly annuals. Of course, once tough perennials like quackgrass have gotten established you'll be working a bit harder to yank them out. If a bed is so overrun with this type of weed that tilling is necessary it is a good idea to quickly sow a thick cover crop after tilling to suppress weed growth – for example, buckwheat sown during the summer grows vigorously enough to out-compete weeds, but it will need to be tilled again before it flowers to keep the buckwheat from reseeding.