Agricultural Drainage

This page was adapted from the article, "Agricultural Drainage" which appeared in Crop & Pest Report on May 19, 2022.

Drainage is needed in many soils in the region, due to poor natural internal drainage. Many fields remain waterlogged for several days after excess rain without artificial drainage. This prolonged wetness prevents timely fieldwork and seeding. Wet conditions after seeding may cause stress to growing crops, because saturated soils do not provide sufficient aeration for crop root development. The roots of most crops grown in North Dakota and northwest Minnesota cannot tolerate excessively wet conditions for more than a couple of days. Soil conditions that make drainage a necessity for some agricultural fields include those with slow water permeability or dense soil layers that restrict water movement.

Agricultural drainage is the use of surface ditches, subsurface permeable pipes, or both, to remove standing or excess water from poorly drained lands. During the late 1800s, European settlers in the Upper Midwest began making drainage ditches and channelizing (straightening and reshaping) streams to carry water from the wet areas of their farms to nearby streams and rivers. Later, farmers increased drainage by installing subsurface drainage pipes generally at a depth of three to six feet. Until the 1970s, most subsurface drainage pipes were made from short, cylindrical sections of concrete or clay called "tile." That is why terms like tile, tile drainage, and tiling are still used, even though most drainage pipe today 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. In some areas, surface inlets or intakes (risers extended from underground pipes to the surface) remove excess surface water from low spots in fields.