Effects of soil compaction

Tony Nye - OSU Extension

The last couple of years have been hard on agriculture when we think about the impact our weather and climate has had on farming. Wet springs, wet fall harvests along with bigger equipment have all contributed to what is known as compaction.

Compaction has been getting more attention lately because we are seeing more and more evidence that compaction exists on our farms and in our fields — and the effect is dramatically impacting production and soil health.

The fall of 2018 and spring of 2019 created some less than ideal conditions for field work leaving many farmers concerned with field compaction. This concern is justified as compaction can significantly reduce yields. Compaction has been a concern for many years as equipment size grows, increasing axle weight.

Researchers have been conducting on-farm trials comparing farming practices to uncover ways farmers can reduce compaction. Comparisons include tires and tracks, equipment size and tillage practices.

To give you some basic background to compaction, the information I am going to share this week comes from Ross H. McKenzie Ph.D., P.Ag. Research Scientist – Agronomy Agriculture Research Division Alberta Agriculture and Rural Development Lethbridge, Alberta. It is basically just an introduction to the soil compaction and the effects of compaction.

McKenzie notes the various forces of soil compression by agricultural equipment can cause soil particles to become compacted closer together into a smaller volume. As particles are compressed together, the space between particles (pore space) is reduced, thereby reducing the space available in the soil for air and water.

The compaction force may cause the crushing of soil aggregates, which has a negative effect on soil aggregate structure.

Soil compaction can have a number of negative effects on soil quality and crop production including the following:

• causes soil pore spaces to become smaller

• reduces water infiltration rate into soil

• decreases the rate that water will penetrate into the soil root zone and subsoil

• increases the potential for surface water ponding, water runoff, surface soil waterlogging and soil erosion

• reduces the ability of a soil to hold water and air, which are necessary for plant root growth and function

• reduces crop emergence as a result of soil crusting

• impedes root growth and limits the volume of soil explored by roots

• limits soil exploration by roots and decreases the ability of crops to take up nutrients and water efficiently from soil

• reduces crop yield potential

Compacted soil will restrict root growth and penetration into subsoil. This situation can lead to stunted, drought-stressed plants as a result of restricted water and nutrient uptake, which results in reduced crop yields.

In wetter than normal years, soil compaction can decrease soil aeration and lead to the increased loss of nitrate nitrogen by denitrification, which is the conversion of plant available nitrate-nitrogen into gaseous nitrogen forms that are lost to the atmosphere.

This process occurs when soils are in an anaerobic condition and soil pores are mostly filled with water. Reduced soil aeration can affect root growth and function, and lead to increased risk of crop disease.

All these factors result in increased crop stress and yield loss.

Precision University

In response to the concern of compaction here in Ohio, the Ohio State University Extension will be hosting the 2020 Precision University. OSU Extension has invited in some of the leading experts from across North America on compaction research and management.

Featured speakers include: Dr. Scott Shearer, The Ohio State University; Dr. Ian McDonald, Ontario Ministry of Agriculture; Dr. Mark Hanna, Iowa State University; and Dr. Jason Warren, Oklahoma State University.

The Precision University will be held Jan. 8 from 8 a.m. to 3:30 p.m. at Champion Center on the Clark County Fairgrounds outside Springfield. This facility allows OSU to feature equipment demonstrations in a heated environment and enables exhibitors to display the latest in technology from their companies.

This is an exciting opportunity to get hands dirty with some compaction demonstrations involving different types of equipment!

Details including online registration and hotel information can be found at go.osu.edu/precisionu. The registration deadline is Jan. 3 and the cost to attend is $50. This includes breakfast, lunch and giveaways.

Sponsors and exhibitors include Camso, Soucy, Green Field Ag, Capstan Ag, Apple Farm Service, Precision Ag Reviews, Ag Info Tech, Mosaic, and Agro Chem.

Tony Nye is the state coordinator for the Ohio State University Extension Small Farm Program and has been an OSU Extension Educator for agriculture and natural resources for over 30 years, currently serving Clinton County and the Miami Valley EERA.


Tony Nye

OSU Extension