Crop & Pest Report

Accessibility


| Share

Water Management (07/06/17)

Although many parts of North Dakota are dry, there are areas in the northern part of the Red River Valley that have received sufficient or even abundant precipitation.

Water Management

Although many parts of North Dakota are dry, there are areas in the northern part of the Red River Valley that have received sufficient or even abundant precipitation. Managing the water table via subsurface drainage is one option to reduce excess moisture in the root zone. Subsurface drainage does not remove plant available water from the soil only excess water. Benefits of subsurface drainage are realized in both wet and dry years. Because subsurface drainage promotes deep root development crops have access to more soil moisture. In Figure 1, an example from 2015 is shown comparing naturally drained (no tile) with a controlled drained field. The lines represent the depth of the water table below the surface over the season. At the beginning of the growing season, the water table was 40 cm (16 inches) below the surface for the non-tiled field, causing less than ideal growing conditions. With the controlled drainage (Figure 2) the water was two feet below the surface at the beginning of the season. As the crops start to develop rapidly in July the crop water use increases and the water table generally drops, as can be seen in Figure 1.

kandel.1

During extremely dry years it is conceivable that a tile-drained field might have less available water at some point during the growing season than an undrained field. Whether or not this would offset the early-season positive effects of drainage is unknown. In general, where poorly drained soils exist, crop yields will be more uniform from year to year with tile drainage. Water table control structures can be used on fairly level fields and this provides the producer with the option to close the outlet and conserve water when needed. A drainage lift pump can be turned off when there is a concern about dryer growing conditions

The benefit of drainage water management is that producers have one more tool to manage production risks. The basic subsurface drainage philosophy is to remove only that amount of water from the soil necessary to create good field conditions and retain water that may contribute to crop production. Under certain conditions, water retained in the soil by the control structures may offer the potential of increased crop yield.

kandel.2

Tom Scherer

Extension Ag-Engineer

 

Hans Kandel

Extension Agronomist Broadleaf Crops

Creative Commons License
Feel free to use and share this content, but please do so under the conditions of our Creative Commons license and our Rules for Use. Thanks.