Although power lines hang far above the ground and themselves don’t inhabit a large area, they do a world of damage to farmland.
Negative impacts on agriculture include but are not limited to:
Navigating large farm machinery around poles and under wires is dangerous. Large areas under the lines are carved out by an inability to drive right up against poles, creating space for weeds and unruly growth. Why stay away from the poles? In many easement agreements, utility companies ensure that landowners are liable for any damages that farming has on their infrastructure – even thought they just throw the poles in the middle of farmable land!
Removal of Windbreaks
According the Wisconsin Public Service Commission’s report of the Environmental Impacts of Transmission Lines, “Windbreaks consist of rows of trees that can help reduce wind erosion by providing a barrier on the windward side of a field. Depending on soil conditions and supporting practices, a single row of trees protects for a distance downwind of approximately 10 to 12 times (or more) the height of the windbreak. The removal of windbreaks because of transmission lien construction, especially in agricultural soils highly susceptible to wind erosion, could result in reduced crop productivity due to permanent loss of top soil.”
Weed and Pest Encroachment
The Wisconsin PSC report also states that “In recent years there has been discussion about the potential for construction projects to spread farm pests and diseases or to otherwise affect the health of farming operations. Concerns have been raised about Johne’s disease, soybean cyst nematode, the spreading of ginseng diseases to plots reserved for future ginseng production, and pesticide contamination of soils on organic farms. Issues of biosecurity can be a concern to many farm operators.” Clearing agricultural land also results in the opportunity for weeds to grow. Weeds steal resources from crops which reduces yields. The picture below shows weeds that have grown up under a transmission line in Missouri.
In order to build gigantic power lines, construction companies drive huge machinery across fields. These heavy machines crush the soil much more than your fist can crush a handful of potting soil. Soil compaction is associated with poor drainage, increased erosion, poor nutrient uptake for crops, reduced microbial activity, and increased fertilizer and pesticide runoff. All of these consequences stunt crop growth. Read more about soil compaction here.
The Wisconsin PSC states that “Soil mixing, erosion, rutting, and compaction are interrelated impacts commonly associated with transmission construction and can greatly affect future crop yields.” Excavating pole foundations mixes soils which can reduce crop yields. Poor erosion controls can result in valuable topsoils washing downhill and impacting waterways and wetlands. “Agricultural soils that have been improperly protected or mitigated may suffer decreased yields for several years after the construction of the transmission line is completed.” – Wisconsin PSC Report
Inability to use Aerial Application
Aerial application of farm inputs (such as spraying for pest-control) is a last-resort when ground application cannot be used. Power lines cutting across fields makes flying overhead an impossibility leaving large areas that have to remain untreated. This can lead to reduced yield and poorer crop quality.