TYPES OF DEEP SOIL PREPARATION
Ecology Action uses 4 basic types of deep soil preparation processes:
- the initial double-dig, shown below
- the basic ongoing double-dig, shown below
- the complete texturizing double-dig, shown below
- the U-bar dig, shown here
The complete texturizing double-dig was developed to improve soil quality more rapidly and is used one time only. It is used usually in place of the initial double-dig, but it can be used at a later point in time. We have found this soil preparation process greatly improves plant health and yields immediately in poor, compacted, and heavy soil. It is often worth the extra digging time involved. However, it does use an insustainable amount of organic matter
- When the soil islightly moist, loosen the top 12 inchesof the entire area to be dug with a spading forkand remove any weeds.
- Spread a ½-inch layer of compost over the entire area to be dug (after mixing in a 1- inch layer of sand or clay 12 inchesdeep; optional, see thispage).
- Remove the soil from the upper part of the first trench and place it in a soil storage area for use in making compost, flat soil and soil for filling in the final trench, when needed.
- Loosen the soil an additional 12 inches.
- Dig out the upper part of the second trench and move it forward into the first trench.
- Loosen the lower part of the second trench.
- Continue the double-digging process(repeating steps3, 4, 5, and 6) for the remaining trenches. Rake after each 3 to 4 trenchesto ensure even bed height.
- Fill in the final trench. Shape the bed by raking it. Then evenly spread any needed fertilizersover the entire area and sift them in 2 to 4 inchesdeep with a spading fork. The double-dug bed isnowcompleted. The U-bar dig can be used asa substitute for the ongoing double-dig in soil that isin reasonably good shape. Thisusually means after one normal double-dig or more.
The 18-inch-long U-bar tines(see thispage) do not prepare the soil asdeeply asa spade and a spading forkused to double-dig 24 inchesdeep, but the lower 12 inchesof the growing bed compact more slowly over time than the upper 12 inches. Also, the U-bar appearsto have the advantage of mixing up the soil strata much lessthan double-digging with a spade and a spading fork. It aeratesthe soil less, however. Thisisan advantage in looser, sandier soil and can be a problem in tighter clays. If you use a U-bar regularly, do a normal doubledig asoften asincreased compaction indicates. U-barring isquicker and easier than using a spade and a spading fork, though some knowledge of howyour soil is improving, or not improving, islost with the decreased personal contact with the soil.
(For detailed planson howto build a U-bar, see thispage or Ecology Action’sThe Backyard Homestead, Mini-Farmand Garden Log Book.) At Ecology Action, we prefer to double-dig, aswe learn more from it and stay more in touch with the soil.