(in gardening) digging in which only the topsoil is turned over, to the depth of one spit.
（园艺）浅层翻土
Example sentencesExamples
The principles are much the same as for single digging, but the trench cut is twice as deep and wide.
In most cases, only single digging is needed, but it's a useful way of cultivating soil in new gardens and where deep top-soil is required.
This follows the same method as single digging, but after removing each trench, the soil below is turned before filling back up with soil from the next strip.
As in single digging, weeds are removed during the process.
Another important factor to be considered is that any single digging project can have multiple stages.