How Soil Compaction Threatens Crop Yields and Resilience

By Blake Jackson

In recent years, both researchers and farmers have become more aware of how soil health affects crop yields.

Many producers are already using soil health practices like nutrient management, reduced tillage, and cover crops to improve productivity and preserve soil quality.

Despite this progress, soil compaction often goes unnoticed, even though it can significantly impact plant growth and soil function.

Kitty O’Neil, an agricultural climate resiliency specialist with Cornell Cooperative Extension (CCE), began investigating this issue more than ten years ago.

Soil compaction occurs when particles are pressed together, reducing pore space and increasing density. According to O’Neil, using heavy machinery on wet fields is a major contributor, as moisture acts like a lubricant, making it easier for particles to shift and compact.

Another cause is equipment design. “Small tire contact area and elevated tire pressure” can increase compaction, she noted. Heavier machines with narrow tires and high pressure concentrate weight into a small area, worsening soil compression. Lower tire pressure and wider tires help spread the load, minimizing damage.

“The extent of compaction in New York agricultural fields is not well known,” O’Neil said. “What we do know is that compaction affects the ability of plants to penetrate the soil volume to find the nutrients and water that they need, and at that point they become less drought resistant.

This is really crucial when it comes to maintaining climate resilience on our farms the more that our farms can adapt to extreme weather conditions, the better.”

To better understand compaction patterns, O’Neil collaborated with the Cornell Nutrient Management Spear Program, including data analyst Manuel Marcaida and PhD student Issa Diaz. They updated sampling protocols and gathered over 8,000 penetrometer readings across seven New York farms. “We amended the sampling protocol with Kitty,” Marcaida said.

Early findings from 2021 showed that lower-yielding zones had more severe compaction. Diaz is now analyzing the full dataset. O’Neil hopes the research increases awareness, noting, “Soil compaction is a form of soil degradation that is difficult for farms to detect and evaluate.”

Photo Credit: gettyimages-zoran-zeremski