Gordon Johnson, Extension Vegetable & Fruit Specialist; gcjohn@udel.edu
This past year, I attended several talks where small growers were using practices where little, or no tillage was done. This eliminated or reduced the need for power equipment. In these growing systems, permanent growing areas are created, and crops are planted through natural mulches.
Sheet or layer composting is one of the basic principles used in these systems. This involves layering materials that will break down over several months resulting in a bed that is easily planted into without the need for tillage.
There are several ways accomplish this. In one system, existing vegetation is covered with waste cardboard (paper mulch can be used for larger areas). This carbon material smothers the grass and weeds underneath. This is then covered with a 1-inch layer of a nitrogen source such as manure. The next layer will be leaves, straw, bark or other carbon material followed by another layer providing nitrogen such as green produce scraps, manure, or fresh green plants (minus the seed heads), or a combination. Continue to add alternating layers of carbon and nitrogen until reaching the final height. Once these layers have decomposed, the bed is ready to plant in. This normally takes about 6 months. Each year, continue to add alternating layers of carbon and nitrogen, as materials become available.
Once created, these sheet composted beds become permanent growing areas, weeds are controlled, and planting can be done using simple hand tools.
For larger areas, one initial (or last) tillage is done and 3-4-foot-wide beds 100 or more feet in length are laid out with paths between the beds. The bed surface is covered with compost and mulch and paths are covered with bark or wood chips. Crops are planted through the compost/mulch on the beds. Each year additional compost and mulch are added to bed, and bark or wood chips is added as needed between rows. Cover crops are planted on the beds between seasons and are laid down or rolled by hand and then planted through providing additional mulch that decomposes. Crop debris also remains to decompose. A rich organic layer develops that no longer requires any tillage.