by Brianna Gwirtz Smith

In the Midwest, crop losses often come down to one thing: water stress. Data from the past 30 years shows that over 70% of insurance payments for crop loss are due to either drought or flooding.

In Ohio, farmers face a two-pronged challenge, often with too much rain in the spring and not enough in the summer.

Northwest Ohio, the state’s grain production hub, has relied on tile drainage systems for more than a century. The area is one of the most intensively drained areas in the world, with 70% to 80% of county acres utilizing drainage systems.

However, these systems that make early planting possible also leave fields vulnerable to drought later in the season. July and August typically bring 3 to 5 inches of rain per month, but crop demands rise to 7 or 8 inches in the hotter months. The 4- to 5-inch water deficit each summer reduces yields, particularly during the critical reproductive stages of corn and soybean growth.

Vinayak Shedekar, assistant professor of agricultural water management at Ohio State University, and his colleagues have been researching new, automated, controlled drainage technology to aid in late-summer water deficiency.

The project is sponsored through the AgTech Innovation Hub, an ongoing collaboration between the OSU College of Food, Agricultural and Environmental Services; Nationwide: and the Ohio Farm Bureau.

Smart water management

Controlled drainage, the act of closing and opening tile outlets, is not new.

“Between November and April, farmers are not growing many crops. By retaining the water in the field and not letting it drain, research shows there was tremendous water quality while reducing the amount of nitrate,” Shedekar says. “On average, storing water behind those control structures helps increase corn yield by 6% and soybean yield by about 3%. In a drought year, it may look more like 10% to 15% for corn, and up to 10% for soybeans.”

However, controlled drainage also has its drawbacks. Historically, manually controlled drainage has been cumbersome and time-consuming, especially for farms with 10 to 15 water table control structures at drainage outlets. Moving the slide gates up and down in the control structures can be labor intensive.

The key innovation lies in automating the controls on drainage systems. Automated drainage systems solve this problem by using sensors and web-based software to monitor water levels and adjust valves remotely, Shedekar says.

Solar-powered controllers at each valve open or close the system based on real-time data, ensuring the water table stays optimal throughout the growing season.

“Automation allows us to manage water stress with the click of a button,” Shedekar explains. “The system releases water during heavy rains and retains it when crops need it most, especially during hot July and August days.”

This controlled retention of just 1 to 1.5 inches of water can sustain crops for up to 10 days, which can be beneficial during the crop’s reproductive stages.

Pilot project in the works

Shedekar’s team has been working with northwest Ohio farmers on a pilot project on automated controls for the past few years. They also compare fields that use manual-controlled drainage systems versus automated means.

Some data points they are collecting include soil moisture changes, crop responses, photosynthetic activity of the plants and the hydrologic behavior of the soil.

Early results indicate that automation is influential for crops.

“The automated fields have had a little more soil moisture than the manual fields, and there is a clear contrast between the fields as it relates to crop photosynthetic activity. The crops in the automated fields were more active versus the crops in the manual control drainage fields,” Shedekar explains.

“This is a very good indicator of how the automated approach keeps crops more active and growing. If water is available, crops will continue to grow even during the hottest part of the day.”

Their project will continue for a few more years. Shedekar hopes to investigate how the automated controls also impact water quality, including phosphorous and nitrogen levels.

“The highest 20% of annual precipitation, so those big rain events, cause 40% of annual runoff alone. That results in about 60% to 75% of the annual dissolved phosphorous loss,” Shedekar says. “With active management of storage systems, there could be significant decreases in nutrient runoff.”

Gwirtz Smith is a correspondent for Farm Progress.