What information can you give me on spading machines?

C.D.PennsylvaniaAnswer: Thank you for your recent request for information from ATTRA, the National Sustainable Agriculture Information Service. I am pleased to provide you with information on spading machines.The Spading Machine is a tillage tool made up of several spade shovels that are connected to a crankshaft. When engaged through the PTO, each spade enters the soil through a slicing motion and breaks the soil off at the bottom of the spades stroke. This allows the subsoil base to break rather than being cut or polished, which results from plowing, discing, or rototilling. A spading machine loosens the soil in a single pass which promotes percolation and root penetration. Other tillage implements can achieve this, but often results in soil compaction. The motion of the spader works to eliminate compaction or disruption to the soil profile within a single pass. (However, spaders will invert the soil with repeated passes). Spading machines also require low horsepower to operate. This is due to having each spade shovel taking a turn at entering the soil. Spaders can also be adjusted to till deep or shallow and in fact, can often penetrate the soil deeper than other types of tillage implements. All of these components allow for a spader to be used to till damp soils which then opens up the soil so that it can dry out. Therefore, a spader is an ideal primary tillage tool for early spring plantings. There are two types of spading machines; articulating and rotary. The spades on an articulating spader, or true spader, go straight down into the soil and tips back on the up stroke, throwing the soil against the rear door to break it apart. Used on sandy soils, an articulating spader can produce a finished seed bed and incorporate cover crops and green manures. Depending on the amount of clay in a soil, these spaders tend not to produce finished seed beds or incorporate green manures very well. A heavy clay soil may require the use of a rototiller or other finishing tool to be used after spading to prepare the bed for planting. There are several spaders on the market; most of them coming from outside of the U.S. A few of the more well-known names of spaders include Celli, Imants, Falc, and Tortella. In addition, there are spaders available for walk-behind tractors, including BCS and Farrari.