Dig a shallow hole in your soil approximately 3 - 4 inches deep and 2-3 inches wide (taking care not to damage surrounding plantings or turf).
Gather a small handful of topsoil (from the bottom of your test hole) in the palm of your hand and lightly squeeze it.
Observe the results of your squeezed soil sample and compare to the following:
0-25 percent available water moisture - Time to break out the sprinkler!
You should observe: Dry, with soil clumps which break into smaller pieces easily when pressure is applied, no staining on fingers, (Not pictured)
Water needed: 1-2 inches of water - Water in one hour increments to provide approximately 1 inch of water.
25-50 percent available water moisture - This is the sweet spot!
You should observe: Lightly moist soil which forms a weak ball, no water staining on fingers.
Water needed: 0 to 1 inch of water - Only water if soil is readily crumbling indicating moisture is around 25%.
50-75 percent available water moisture(Figure 2) - Time to let the lawn dry out for a couple of days before retesting.
You should observe: Soil is moist and forms a ball with very light staining on fingers. Less likely to crumble, darkened color, pliable and can me manipulated into shapes fairly easily.
Water needed: None, Let the soil dry out for a couple of days before retesting.
75-100 percent available water moisture (Figure 3) - You tested after a recent rainstorm, didn't you?
You should observe: Wet, forms a ball with well-defined finger marks, light to heavy soil/water coating on fingers, easily manipulated into shapes which hold their forms.
Water needed: None, the lawn is nearly fully saturated. Wait a few days before retesting.
100 percent available water moisture (soil is at capacity) - Don't walk on that lawn (no Seriously)!
You should observe: Soil is wet and will move beneath your feet leaving foot prints and potentially damage turf. It will form a soft ball and free water appears briefly on soil surface after squeezing or shaking leaving medium to heavy soil/water coating on fingers. (Not pictured)
Water needed: None, the lawn is at capacity and can accept no more moisture. Wait several days before retesting.
Appearance of Sandy Clay Loam, Loam, and Silt Loam Soils
Estimating Soil Moisture