Soils vs. Dirt
Terrestrial life lives in the air. Aquatic life lives in water. Plants live in the soil which is neither wholly air nor wholly water but a combination of the two. Soil life requires a blend of air and water to survive. Dirt is something you sweep up in the kitchen.
To Be a Soil, You Must...
A soil has three elements: solids, air, and water. The solids in our soils in Pinellas are mostly sand. Soil air comes from the atmosphere - there is always a constant air exchange between soil and atmosphere. But water is dependent upon rain. When it does not rain, the soil dries out and every living thing in it dies
Why A Dry Soil is a Dead Soil
Water in the soil has critical functions. Water is the medium in which the delicate microscopic creatures work their magic composting organic matter into plant food. Water transports the nutrients created by microbes to the roots for consumption. Only nutrients dissolved in water can be absorbed by the roots. When a soil dries out the microbes die, nutrient-rich water dries up and roots can no longer take up nutrients.
Recovery is Possible
It is a big loss when the soil dries out. But if you resume watering the lawn can recover. However, for best results, you should keep the soil moist 24/7/365 - letting your soil cycle from dry to wet is not as good as constant moisture.
Irrigation is Mandatory
I tell customers all the time "You're not going to kill your lawn with water" It is almost impossible to destroy a lawn with water in our sandy soils. However, it will die in a week if you don't water." In Pinellas, irrigation is not optional, it is mandatory.