Trench composting (also called pit composting) is a good alternative for small vegetable gardens where there is not room or desire for a compost pile. This is a rotational system using sets of three rows which will be referred to as Row #1, #2 and #3.
First Rotation: Row #1=Trench…..Row #2=Planting…..Row #3=Path
Row #1 should be dug 10 – 12” wide and a foot deep. You may want to deposit the soil from this trench on Row #2. Next, plant seeds or seedlings in Row #2 as desired. Row #3 is used for a path so that you have access to the other two rows. Prepare the next three rows in the same way, and so on.
Deposit organic wastes in Row #1 as they are generated. For safety, you may want to put a barrier around, or boards across trench one to prevent someone accidentally stepping into it.
Second Rotation: Row #1=Planting…..Row #2=Path…..Row #3=Trench
When you are ready to plant again, dig the trench in Row #3, moving excess soil to row #1. Row #3 will be used to deposit wastes. Row #1, in which organic materials were most recently deposited, will provide fertile ground for seeds and seedlings. Row #2, most recently used for planting, will be left fallow during this rotation and will be used as a path.
Third Rotation: Row #1=Path…..Row #2=Trench…..Row #3=Planting
At the next planting, Row #2 should be dug as a trench, Row #1 left fallow as a footpath, and Row #3 will be used for planting.
Following this method, organic materials are continuously added to the soil for planting the following season, and spent ground always lies fallow for a season before being replenished with more organic material. Caution should be taken not to deposit diseased or pest-ridden wastes in the garden as pathogens could remain dormant in the trench and infest the next crop.
Mary Tynes, Master Composter, www.mastercomposter.com