As any farmer will tell you, the health of the soil is directly responsible for the health of a crop. More than just the essential nutrients and water, the roots of plants need air pockets and microorganisms in the soil as well. This allows the plants to be able to properly intake nutrients like nitrogen (N), phosphorus (P) and potassium (K) available in the soil to grow large and strong.
Unfortunately, much of the heavy machinery now commonly used on farms can have a negative impact on crop growth. Soil compaction due to frequent passes from agricultural equipment can lead to stunted growth and unhealthy plants. It can also make the plants less robust and prone to pest infestation and disease.
Here are three negative ways that high traffic and soil compaction impact plant growth.
Disappearing air pockets
When soil is compacted, it becomes dense. This means that roots are not able to push through the heavy soil by weaving through the air pockets.
Penn State Extension notes that “Large pores (called macropores), essential for water and air movement in soil, are primarily affected by soil compaction. Research has suggested that most plant roots need more than 10 percent air-filled porosity to thrive.”
The roots resulting from plants in compacted soil end up very malformed and shallow due to their restricted growth. Malformed roots are not able to uptake as much moisture and nutrients which lead to common deficiencies in nutrients like nitrogen and potassium. To compensate for these deficiencies fertilizers may need to be applied which can dramatically increase production costs.
Restricted roots can also lead to increase in root-related diseases and other damage as well.
Loss of bacteria and fungi
As farm equipment gets steadily larger and heavier each year, farmers need to give more attention to issues stemming from soil compaction than they ever had to in the past. One such issue related to compaction is a loss of important and beneficial microorganisms in the soil. These microorganisms – like bacteria and fungi – help create a living, dense soil filled with organic matter and available nutrients.
The majority of fungi and bacteria are benevolent – performing helpful functions in the soil system such as plant residue decomposition, nutrient release, and aggregate formation.
Penn State Extension clarifies the various roles of these important microorganisms. “Some bacteria such as rhizobia provide nitrogen to plants. Some fungi live in symbiosis with plant roots, facilitating the uptake of immobile nutrients such as phosphorus and potassium.”
Anaerobic conditions in compacted soil can quickly lead to denitrification of the soil as well – stripping the soil of important nutrients that plants need to thrive.
An article by Jodi DeJong-Hughes regarding tires, traction and compaction from the University of Minnesota Extension noted that heavy farming and agricultural equipment can have a negative impact on our roadway system as well.
In a chart for the publication, DeJong-Hughes documented that in less than 30 trips, a loaded 875-bushel grain cart makes the pavement unstable.
DeJong-Hughes noted, “If the same load was transferred to a 7-axle semi-truck, it would take 175,000 passes for pavement failure. If this is what is happening to the roads, imagine what is happening to our soils.”
While we may not be able to stop all compaction, we can be sure to educate and inform farmers about the harms, and known alternatives, like low or no-till farming, and other organic lower yield more nutrient dense farming practices and other permaculture techniques.
Sherley Alaba is an undergraduate student. She loves to write about the top trends in sustainability, finance and lifestyle.