Spring and summer drainage and water management for grain crops

By Vinayak Shedekar, The Ohio State University

As I write this article on the last day of March 2025, about 3 to 4 inches of precipitation is expected across the state of Ohio by April 7. The 30-year normal monthly precipitation for April is about 4 inches. This means, you may have received an entire month’s worth of rain in just one week! The National Weather Service (NWS) recently issued the 2025 U.S. Spring Outlook, covering precipitation, temperature, flooding, and droughts. You can find more details on the Climate Prediction Center website.  For conditions specific to Ohio, a monthly climate summary is published online by the state climate office of Ohio.

Coming out of the recent drought conditions from 2024, the above-average April precipitation may have helped replenish the soil moisture in northwest and southeast Ohio. Most soils in Northwest Ohio are now oversaturated, leading to significant amounts of subsurface drainage discharge. The following drainage and water management strategies apply to Ohio and may also be relevant for neighboring states, depending on local climate and soil conditions.

Newly installed drainage systems: If you recently installed a new drainage system, the soil above the pipes (tile trenches) is still settling. It may feel like the system is overwhelmed with water, but that is normal, as the disturbed soil profile above the drains is acting like an open trench while the soil settles. It is normal to observe more sediment loss in the spring after drainage installation. Allow for the sediment to flush out of the system by keeping the outlets unobstructed. That means, if there is a water table control structure, pull the bottom board up, so that the outlet can flow freely. Further, observe the outlet conditions more often, and inspect for excessive bank erosion/under-cutting under the tile outlets. 

Controlled drainage/ drainage water management: If fields are being managed under controlled drainage (i.e. maintaining higher water table by stacking stoplogs), now is the time to visit & inspect those control structures! Typically, we recommend reverting to “free drainage” mode at least two weeks in advance of planting date. If excessively wet conditions are anticipated, lower the water table three weeks prior to planting. Many experienced drainage contractors recommend clearing obstructions from the outlet at least once a year to flush out sediment and debris (e.g., dead roots). If the structure uses a series of stoplogs, keeping some stoplogs in the structure can help resist soil pressure on the walls. But, make sure that the stoplogs do not fall to the bottom before planting and cause obstruction to the free flow of water. If liquid manure application is anticipated, then use of controlled drainage is essential to avoid short-circuiting losses of manure to tiles. The water table should be set deeper in fields where cover crops are starting to grow deeper roots. For more details refer to this Ohio’s Country Journal article.

Late spring/summer management: The long-term outlook for the United States is suggesting above average temperatures in late summer. If this trend continues, expect dryer conditions due to excessive evaporation losses. It may be wise to start thinking about partial water retention with the help of controlled drainage systems towards the end of June or early July. In a 3-ft deep drainage system, adding one or two stoplogs in a control structure would allow for water table to rise by about 6 to 12 inches above tile lines. This may help retain some water for the later part of the growing season. The decision to retain water should be made based on forecasts for wet vs dry conditions during these weeks. During late summer, I have observed growers add stoplogs such that, the anticipated water table rise can be as high as 12 to 24 inches above the tile drains. Our long-term field studies and computer model simulations suggest that corn and soybean can benefit from the additional water stored in the soil profile, especially, during the reproductive stages of these crops.

Soil health and water management field day (OSU Lima, Ohio): Please mark your calendars for the upcoming soil health and water management field day at OSU Lima, Ohio, scheduled on Aug. 28, 2025. The event will feature expert presentations and a farmer panel on cover crops, soil health, farm economics, and water management. Attendees can also participate in field tours and demonstrations. More details will be posted on the websites of my program and the Ohio No-Till Council

This column is provided by the OSU Department of Food, Agricultural and Biological Engineering, OSU Extension, International Program for Water Management in Agriculture, Ohio Agricultural Research and Development Center, and the College of Food, Agricultural, and Environmental Sciences.

Dr. Vinayak Shedekar is the Assistant Professor of Agricultural Water Management and director of the Overholt Drainage Research and Education Program in the OSU Department of Food, Agricultural and Biological Engineering and can be reached at shedekar.1@osu.edu