We had a lot of rain in the last week. Water is standing in fields. Some fields will stay saturated for some time to come. There will be impacts from the excess water. The impacts will vary from field to field but we can be sure that there will be impacts from the excessive water. We are now in a wait and see mode.
The problem with excess moisture is that the roots of the plants finally run out of oxygen. This means that there will be damaged roots left after the flooding episode is gone away. If the roots are damaged, further plant development will be impaired.
Of the cereal crops, oats can tolerate the longest periods of flooding. Wheat is the next best crop and barley has the poorest tolerance to saturated soils. With oilseeds, canola has good flooding tolerance. With peas, it is the most susceptible to flooded soils. With the amounts of rain that we have seen in the last few years, we have all seen the impacts of flooded fields.
Fields with more growth should have an easier time dealing with excess moisture. These fields have used more moisture preceding the rain and the soil has room for more room for moisture. The plants have an extensive root system that should have better capability to handle the excess moisture. The plants that are most susceptible to excess moisture are the ones that are just germinating. Germination is a delicate process that requires oxygen. If this process is disrupted, poor root development will be the result.
Corrective measures for flooding needed to already be in place. Proper surface drainage is essential for moving excess moisture off of fields. Minimizing the length that the water stays in the field will reduce root damage. Crops that have had seed treatment applied should have better tolerance to saturated soils. This is because the root systems on these plants should have less disease before the rainfall.
One special consideration that we must be aware of is what happens in saturated fields when we have excess moisture. The first thing that happens is that growth is reduced. On poorly drained soils, this could have a major impact on weed control. Plants are under stress and some herbicides could cause plant injury. Weeds are under stress and the weed control that is expected could be below our normal standards. Delaying the application of herbicides for a couple of days may do more than reduce the amount of ruts in a field.
With farming, we have to live with the weather that we are given. We can prepare to deal with adverse weather by putting the best management practices in our fields. Healthy plants have the ability to withstand more stress than ones that have been injured by excessive moisture. Once the stress from too much moisture has occurred, we can implement best management practices that will allow the crop to recover before we use herbicides. Implementing these practices should allow us to grow more bushels.
By Dave Cubbon, P Ag