Don’t let drought (un)shock the system

Drought can take an obvious toll on forage supplies, stand condition, and water resources, but the effect it has on electric fences may be less apparent. Less apparent, that is, until livestock escape a pasture because the fence didn’t hold a charge strong enough to deter them.

Dean Kreager, an agriculture and natural resources educator with Ohio State University Extension, says there are fencing issues specific to drought that can cause havoc in grazing systems if left unattended. These problems primarily stem from weak grounding rods and loose fence posts.

Weak connections

Although wet conditions can lead to electrical faults when forage and weeds overtake fences and reduce the electrical charge, Kreager states these faults are less of a concern in dry conditions since stressed forage isn’t usually as tall. Instead, electric fences may malfunction during drought because ground rods are less effective in dry soil. Some moisture is necessary to maintain a strong electric circuit.

“During very dry conditions, the conductivity between the animal and the ground is reduced,” Kreager explains. “Hard, dry hooves and dry grass act as insulators. This would be like grabbing a fence wearing leather gloves and rubber boots; one will likely not feel a shock.”

Additionally, Kreager contends many electric fence chargers are installed without sufficient grounding. In general, there should be 3 feet of ground rod per joule of output from a fence charger. Therefore, a 6-joule charger would need 18 feet of ground rod attached, ideally with 6-foot rods spaced 10 feet apart.

“Longer rods are preferred as they are more likely to reach moist soil,” Kreager says. “Adding ground rods may improve the effectiveness of the fence charger during dry conditions.”

Other solutions

Alternating positive and negative wires on a fence is another option to improve a grounding system. Kreager says attaching noncharged wires to a grounding rod on a high tensile wire fence provides a grounding source where dry grass and cow hooves act as insulators. “When the animal touches both a positive and a negative wire, they are shocked,” he asserts.

“A third helpful way to maintain the effectiveness of the fence charger is to moisten the soil around the ground rods,” Kreager continues. For example, the slow drip from a bucket of water with a small hole in the bottom could supplement soil moisture enough to improve grounding activity if the bucket is placed over a ground rod.

Kreager notes loose fence posts are another fencing issue separate from electrical problems. Depending on the soil texture, dryness can cause soil to contract and force fence posts upward. These loose posts are more prone to leaning, especially if animals come into contact with them, which could make way for an unwanted escape route.