Fertilizing lawns

My front lawn sprinkler system has some problems with coverage. In a couple of places, water from a popup sprinkler passes over a spot without watering it. This makes the lawn look spotty. After significant and unsuccessful tinkering with watering modes, sprinklers, fertilizers, and even water traps, I observed that the grass really goes wild where I drive shrub feed stakes into the ground. I took a wedge, crushed it with a hammer and pressed fragments into the ground in the worst spot. The result was a dark green spot. Well, anything is better... But it's interesting how the chemicals make the grass to accept the water better. This may have some significant implications for the consumption of water.