How water moves in the soil

We have a lot of wet fields in the area.  It has meant that some acres have not been seeded.  Wet fields mean that producers have had spent hours pulling equipment out of mudholes.  All these issues indicate that we need to better understand the hydrology of our soils.

Hydrology of the water is our soils is all about how the water moves in the soil.  When there is room for water in our soils the water will enter the soil pores.  Excess water will move down until it reaches an obstruction like bedrock.  In a dry year, this means that the impact of saturated soils in the farming community is minimal because there is no excess water to be dealt with.  It all run away in the creeks and rivers or it is soaked up by growing plants or moves away through the soil pores to a deeper level in our soils.

When the soils are saturated, the movement of water in our soils change. To get rid of the excess water, there has to be evaporation or sideways movement of the water through the soil profile.  When sideways movement happens, excess water shows up in the low areas of the fields and they stay wet for extended periods of time.  Understanding where the water is coming from with a saturated soil is essential when trying to determine a solution to the wet soil issues.

If water is trapped in a low lying area and there is no possible way for it to move down and away through the soil pores, the only way for the water to move is up through evaporation.  For small amount of localized moisture, tillage can help dry out an area.  For areas that are being recharged by larger bodies of water or bigger drainage areas, the solution to the problems become more complex.

Surface drainage can help reduce localize areas that have saturated soils. If the excess moisture moves into the creeks and river faster, this means that less water has to leave through evaporation or through sub-surface movement.  Moving water through drainage ditches can create problems if it causes flooding on adjacent properties.  When developing a surface drainage plan, be sure that all provincial and federal regulations are adhered to.

Understanding how the water is moving in the soils on your farm could help develop a plan to deal with issues related to saturated soils.  If you are considering specific activities that will help dry up the wet soils on your farm, consider talking to a professional in the field that can assist with the plan.  The first place to start is to try to figure out where the water is coming from.  Knowing the history of the land and finding someone that understands soils of the area would be an excellent starting point.  Soil water must be managed to grow more bushels.


By Dave Cubbon, P Ag