MSU Extension Agrifood Safety

Irrigation Methods From Most to Least Risky:

Overhead (e.g. sprinkler)

Most Risky

The overhead irrigation method is a direct water application method that results in contact with produce, making it the most risky. 

Flood (e.g. surface, furrow)

Somewhat Risky

The flood method is somewhat risky. It results in direct contact with produce above the soil, but may occur less often than with overhead irrigation. However, potentially contaminated water could splash on to the produce or wildly distribute contamination across the soil, which then would be a hazard to the produce. 

Drip (e.g. trickle, subsurface, micro)

Least Risky

Drip irrigation delivers water through the surface or subsurface of the soil, so direct water contact with produce growing above the soil is minimal. This makes it the least risky method out of the three. However, root crops or crops growing on the ground can still be directly contacted, so there are still some risks to keep in mind. 

Source: Produce Safety Alliance Grower Training Module 5-1, slide 15