Ever heard of the illusory truth effect? It’s the idea that if you repeat a false claim often enough, people will slowly start to believe it’s true.

As pig farmers — or just about any farmer, nowadays — oftentimes its common to see a small group of people begin a drumbeat filled with falsehoods. They chant it over and over to the point where people may begin believing it.

This may be why, when you hear that pig manure actually improves soil health and better protects water quality, you may think, “Impossible!”

Yet numerous studies confirm that when farmers switch to swine manure as their crop fertilizer, it’s better for the soil, and better safeguards Iowa’s water sources from nutrient runoff. Here’s how:

• Manure increases the amount of water soil can hold, which reduces nutrient runoff.

• Manure better restores the health of the soil by increasing organic matter.

• Continued use of manure helps build up soil health even more.

• Using manure as a crop fertilizer, along with injecting manure, is a key part of Iowa’s overall effort to reduce nutrient loss into water sources.

To learn about the ways manure builds the soil and better protects against nutrient runoff, check out these resources:

• Impact of Manure Application on Organic Soil Matter

• Soil Health — Impacts on Hydraulic Properties

• Effects of Agricultural Nutrient Additives on Surface Water Quality

• Reducing Nutrient Loss: Science Shows What Works

Source: Iowa State University