Why Soil Columns?
In the field of plant research it is often desirable to grow plants under controlled conditions to minimize environmental variability from one treatment to the next. The desired control can be achieved by growing plants in containers in a greenhouse or growth chamber.
Plant growth in soil is straightforward in the field where soils are deep, but soil moisture dynamics are altered significantly in small containers. Drainage in the field results from the depth (thickness) of the soil layer. Gravity alone is not adequate to remove water from agricultural soils in pots.
Soil columns are an improvement over pots because they are deeper and can therefore hold more soil and more plant-available water; the longer the column, the better the water dynamics. A small surface area to depth ratio enables the use of many columns and the application of several randomized treatments within a small area.
Chard, Julie K. and Bugbee, Bruce, "Simulating the Field: How to Grow Plants in Soil Columns in the Greenhouse" (2005). Techniques and Instruments. Paper 8.