The study compared different ways of watering trees in a forest to see how it affects the soil. They found that using sprinklers to water the trees made the soil less dense and increased its ability to hold water. This means that sprinkler irrigation can improve the quality of the soil in forests. Flood irrigation, on the other hand, did not have the same positive effects and actually wasted water. So, using sprinklers is a better way to water trees in forests.