Throughout my college classes in agriculture, our professor always encouraged the double dig. The idea is that as you prepare your gardening space for planting the first 2 feet of soil should be aerated for healthy roots to develop and crops to be abundant. However, the lower foot needs to remain the lower foot and the top foot section of soil remain in the top foot. The layers of soil have nutrient and soil type contents specific to their location. Consequently you must remove the top foot, mix the bottom foot of the 2 feet and replace the top foot back into place. The theory is roots need air and space in the soil to properly grow, pull surrounding water, and thus use available nutrients. It is a great idea for getting new ground ready, but wow it is a lot of work. And the question haunts my mind, is it really worth all that hard labor?
The old fashion rototiller is certainly easier for larger areas. However, the problem with such tilling is that the tiller almost always creates a hard pan of soil about a foot down where it cannot reach. Therefore, vegetables with extensive roots have a difficult time yielding well. My solution in the past has been to till and shovel my desired paths on top of the beds. This creates a deeper tilled soil and obvious paths for walking. The paths also protect the roots from compaction as I walk around the beds rather than right next to the rows.
One of newer theories in soil development is the no-till method. Agriculturists from typically the organic side say that when we till we breakup important and good bacteria spores. And when they are left alone they work to breakdown nutrients and organic matter into forms which plants can easily consume. Consequently tilling the soil actually slows the production of food for our vegetables. Rather than stirring up the soil with amendments and compost, the organic material or manure is piled on top of the garden bed in the fall. Then the decomposed material is ready for planting in the spring. This is an interesting idea and certainly involves less labor.
There seems to be merit to both concepts. After a garden bed has been tilled, if you keep it weed free throughout the season, it would be easy to just gently loosen the beds with a pitch fork in the spring for planting. Or you could gently turn the composted material over with a shovel to create air beneath the ground. I believe the trick is to apply the theories as well as possible without creating an overwhelming amount of work. I want to benefit from the new practical theories without loosing hope in ever finishing my soil prep.
