Maximizing Returns: Long-Term Benefits of Surface and Subsurface Water Management Strategies for Illinois Farms

by Brynna Sentel
10 minutes read
Water Management

Enhancing your crop yields this harvest season starts with an effective water management strategy. Discover the benefits of surface and subsurface drainage systems on Illinois farms.

Illinois soybean farmers were dancing in the rain recently after experiencing a six-week drought. Finally, the crops were able to enjoy a long-awaited drink in August. Heavy rainfall begs to bring up the conversation of improving water drainage in Illinois row crops.

Illinois has luscious rolling ground in the North and South regions; however, most of Illinois is flat ground, making effective water drainage systems essential for farmers in the Prairie State. The type of drainage system required is determined in part by the soil’s ability to carry water. Cost-effective farm water management strategies include both surface and subsurface drainage systems.

The Importance of an Efficient Water Management System

Over ten million acres of Illinois farmland have subsurface (tile) water drainage, as well as another several million, have some form of surface drainage system  – a necessity for Illinois farmers.

Excessive water in the soil limits the amount of oxygen available to plants and stunts their growth. Protecting the soil structure and soil aggregation which allow for water infiltration, is one of the keys to surface and subsurface water management. This is particularly crucial for Illinois farmers because of the connection between water infiltration and tile drainage. Drainage may contain either surface or subsurface techniques or a combination.

Surface and Subsurface water management techniques reap several benefits when used in tandem, such as:

-Improved balance of water and air in the soil, coupled with timelier field operations

-Reduced flooding

-Less surface runoff

-Improved soil structure

-Enhanced herbicide assimilation

-Healthier roots

-Elevated crop yields and quality through surface and subsurface drainage

Choosing a Water Management System: Surface Drainage vs. Subsurface Drainage

Surface water drainage is most appropriate on farms where soils are impermeable and would require too many subsurface drains to be economically feasible. Soils of this type are common in southern Illinois. Flat land, slow infiltration, low permeability, and on soils with restrictive layers close to the surface. Surface drainage removes excess water off the soil surface through water channels like ditches, field drains, laterals, and parallel ditches.

Subsurface water drainage is more often known as tile drainage. Tile drainage systems consist of tubes made from plastic, clay, or concrete which are buried at a certain depth within the soil. These tubes serve the purpose of facilitating the natural movement of water out of the soil due to gravity. The water is guided along the tile lines until it reaches a lower point in the landscape, either through an outlet or a location where it can be pumped to enter a gravitational drainage system.

By eliminating only the excess water that would otherwise render the land unsuitable for cultivation during certain periods of the year, tile drainage has significantly increased the amount of land available for productive use. Additionally, this system efficiently removes water from the landscape at a faster rate than would naturally occur through streamflow or downward percolation into an underlying aquifer.

How to Maximize Performance of a Subsurface (Tile) Drainage System

For a tile drainage system to operate effectively, water needs to both penetrate the soil surface and permeate down to the tile depth. The functionality of the tile system is determined by observing the amount of water that drains from the lower end of the line.

In agriculture, timing plays a crucial role in achieving profitability. Water should not remain on the soil surface from planting to crop harvest. During this period, farmers require access to the fields for planting, spraying, harvesting, and other operations, as the plants need moisture – not waterlogged – soil to support their growth.

Plants are still able to obtain moisture with tile drainage. This is where soil health and stable soil aggregates come into play. Subsurface techniques drain soil to a greater depth than the surface. 

Other factors may hinder the expected benefits of installing tile drainage. Illinois Soybean Association Research Data Scientist, Stacy Zuber says, “If water isn’t able to make it down through the soil to the tile, the tile doesn’t fully fix the drainage problem. If you are talking about maximizing returns—this is a great issue to highlight as many Illinois farmers spend thousands of dollars on tile drainage and may not see the full benefits when the water isn’t able to move into the soil and never reaches the tile.”

Outreach Agronomist Stephanie Porter from Illinois Soybean Association points out, “There is also Conservation drainage such as practices that optimize production, environmental, and water supply benefits.  Examples are as follows:  controlled drainage, denitrifying woodchip bioreactors, saturated buffers, constructed wetlands, blind inlets to replace tile risers, and drainage water recycling.”

It should also be noted that the Illinois Nutrient Loss Reduction Strategy (NLRS), sets a long-term goal of reducing loads from Illinois for total phosphorus and total nitrogen by 45%, with interim reduction goals of 15% nitrate-nitrogen and 25% total phosphorus by 2025.

Illinois weather has truly put its farmers through an emotional rollercoaster in 2023. Rain or shine, it is our goal to educate Illinois farmers on how to maximize their crop yields this harvest season. Explore more recent findings and strategies to help Illinois farmers like you enhance crop production.

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