Problems with Water Drainage?
Consider Tiling This Fall

By Hans Kandel, NDSU Extension Agronomist
hans.kandel@ndsu.edu

Water management is an important factor in crop production and many producers already have surface drainage ditches in their fields. The next management step is to consider if the subsurface moisture can be managed as well. Water management is the use of surface ditches, subsurface permeable pipes, or both, to remove standing or excess water from poorly drained fields.

During the late 1800s, European settlers in the Upper Midwest began digging drainage ditches to remove excess water from the wet areas of their fields to nearby streams and rivers. Later, producers in what is now the ‘Corn Belt’ increased drainage by installing subsurface drainage pipes generally at a depth of around three feet. Until the 1970s, most subsurface drainage pipes were made from short, cylindrical sections of concrete or clay called ‘tile.’ Terms like tile, tile drainage, and tiling are still used, even though most drainage pipe now is perforated polyethylene tubing.

When installing a subsurface drainage system, pipes are either strategically placed in a field to remove water from isolated wet areas, or installed in a pattern to drain an entire field. Many soils in the region, particularly in the Red River Valley, have poor natural internal drainage and remain waterlogged for several days after excess rain. This prolonged wetness prevents timely fieldwork and causes stress to growing crops because saturated soils do not provide sufficient aeration for crop root development. The roots of most crops grown in the region cannot tolerate excessively wet conditions for more than a few days.

Farmers must make a significant financial investment when installing an agricultural sub-surface drainage system. This investment is often made for the following major reasons:

1. Tile drainage usually increases crop yields (and potential quality) on poorly drained soils by providing a better environment for plants to grow, especially during years with wet periods.
2. The systems generally help improve field conditions for timely tillage, planting, spraying, and harvesting.
3. The drainage systems are long term improvements in the farming operation and tax laws allow writing off tile drainage costs (see your accountant).

Agricultural engineers have developed depth and spacing guidelines for installing drainage pipes. The newest and most comprehensive system available is controlled drainage, which has become recognized as an effective practice. This practice involves placing simple water control structures at various locations in the tile system to control the water table in the soil based on the management decision of the producer.

It takes time to design a tile drainage system for a field and to obtain the necessary permits. The best period to tile a piece of land is after cool season crops have been harvested. Tiling can be done until the soil freezes.

Information about tile drainage in our region (and the source for this article), can be found at: http://d-outlet.coafes.umn.edu.