We are often asked what the differences are between de-compaction using a terravent system that is used by some contractors or an air spade that is used by us. In this blog we will lay out the differences between the two systems a give our reasons for preferring the airspade system over the terravent.
The Terravent system was developed in the UK in a joint project between a small Cornwall based manufacturing company and Kew Gardens. Essentially it is a hollow probe that once hammered into the soil can be charged with air from attached air tanks, fracturing and de-compacting the soil. A separate tank on the terravent can be filled with substances to inject into the soil at the same time as the injection of air, such as fertilizer or nutrient mix. This system works well for vertical de-compaction however it can be limited by needing to recharge the air tanks and only having a predefined amount of air that can be injected in each hole.
The Airspade is a tool initially developed for selective excavation of soil surrounding tree roots. when connected to a high powered air compressor it can be used for a number of arboriculture related tasks including Root Collar Excavation, Root Surveys, and both vertical and horizontal de-compaction.
With the airspade we are able to use it in very similar way to the terravent system, with the main advantage that we are connected to a continuous flow of air, allowing our operatives to inject as much air as is required or to pulse the soil in order to fracture and de-compact it even more.
The other main advantage is that we are able to undertake shallow, horizontal de-compaction whereby the top 20-30cm of soil is turned over using the air spade.
Both tools are useful in the modern management of trees in arboriculture, however, we prefer the use of the Airspade due to its versatility in many aspects of de-compaction and tree healthcare.