Pat turned to me and with excitement in his voice and declared, “That was a “GOOD” rain!” Pat raises cattle. He watches his cattle closely to make sure they have what they need to stay happy and healthy.
So what is a “good” rain? For ranchers, like Pat, it means a rain that is timely. The rain needs to fall often enough to keep the grass growing. No rain. No grass. That’s what we had in 2011.
Photo: Chris Peterson
Timely rains are ones that come before the plant available water in the soil profile is depleted. They are rains that replenish the plant available water that grass and crops pull from the soil. They replace the water plants take in through their roots and give off to the atmosphere as they grow.
Source: Mesonet.org/Weather/Percent Plant Available Water from the surface to 16 inches.
A “good” rain needs to supply enough water to recharge the soil profile. To bring the plant available water back up to the upper amount of what that soil can hold. A full soil profile provides the plant available water needed for grass to grow until the next “good” rain.
Source: Mesonet.org/Weather/7-Day Rainfall Accumulation
Each soil, each field has a water infiltration rate. It’s the amount of water that can be taken in over a time period. If rain “comes too fast,” the soil can not absorb it all. The water that doesn’t infiltrate into the soil becomes runoff from the soil. Runoff from the field.
Photo: Albert Sutherland/OCES
A “good” rain comes slow enough that the soil can take in as much as it can hold. Farmers and ranchers speak of “slow, soaking” rains. That describes rain that comes at the right pace to infiltrate into the soil to recharge the soil profile.
Photo: NRCS
Here’s hoping your next rain is a “GOOD” rain! Just the amount you needed, when you needed it.