Dust, Weeds, and Watermelon Rain
A few weeks ago, I drove pass Highway 304 on Interstate 10. The family ranch is just north of I-10 about 10 miles. This area is often called the sugar-sand grasslands by the locals because of the sugar-like sand that dominates the area. It actually lies within the Post Oak belt. Just past Hwy. 304 and before the Harwood exit, a strong wind carrying a large amount of dust pushed my truck to the center of the road. Even though I was driving on the far-right side of the lane, I was shaken as my truck was pushed within inches of a passing car. The dust was blinding, and the passing car disappeared within a few feet of clearing my bumper. With no one behind me, I quickly hit the brakes to slow down and locate the rumble strips at the side of the road. Lasting less than a quarter of a mile, this was no Dust Bowl event. But it reminded me of past dust storm events. These too were generally short-lived but point up the fact that the wind can pick up dust and send it miles away. In many years, Texas receives dust from Saharan Africa. Dust storms in drought years are not unusual. Grasses that normally hold down the soil have often been eaten to within an inch of the ground by hungry cattle. Brush species, such as yaupon and American beautyberry, have dropped most of their leaves and wind blows freely between plants. As the wind moves, it picks up small particles of dust and draws them skyward. The thing most likely to hold the soil in place is grass cover. Cattle grazing too low to the ground is frequently the problem. Bare patches allow the soil to dry out, further removing any moisture still in the ground. Then the hot, dry wind acts like a convection oven. Fast-moving sand in the air acts like a sand blasting gun. It can punch holes in leaves, kill small emerging buds and leave a coating of fine dust on everything.
Every time a blade of grass is cut in half, (by wind or the bite of an animal) a little of the root system dies with the blade. The lower the grass is cut to the earth, the less root system exists. Tall grasses (those over 8 inches) can be grazed down 50 percent without severe damage to the root system as long as sufficient soil moisture is available. When most native bunch grasses are grazed shorter than four to six inches, any additional grazing will damage the root system. Non-native grasses, such as bermudagrass, are generally not harmed by grazing as low as two inches. Safe grazing heights depends on the grass species.
Two things are critical to grazing cattle through a drought: (1) that grasses are not grazed too low and (2) they have ample time to regrow before they are grazed again. And grasses should never be mowed in a drought unless it is to stop the spread of grassland fires. Too many ranchers mow grasses for aesthetic purposes. A uniform look is not what is needed during a drought. If a drought is anticipated, the best time to mow is when the rains are still falling. Covering the soil during a drought is vital. Dead grass leaves and living plants protect the soil from dry winds picking up dust and hurling it into the air. When rain returns, the soil cover prevents large rain droplets from dislodging the soil. Dislodged soil particles, once dried, become dust as they break down to smaller particles. Covering the soil also helps it to remain cooler and to absorb more water. And most importantly, having grass cover prevents weeds from emerging when soil moisture returns and thus allows grass roots to regrow.
Weeds that pop up during a drought should be welcomed. It is far better to have a weed than to have bare soil. Weeds also retain the soil. Their roots hold the soil, their leaves provide cover and shade, and they bring nutrients missing from harvested plants back to the topsoil. Small whirlwinds and twisters move a lot of dust too. I once saw a white tornado in Gonzales County. I was 15 years old, learning how to drive with Dad in the passenger seat. Heading south on Hwy. 304, I had the truck in the middle of the road. Suddenly the sky turned black and the wind started howling. We heard a sound like a freight train. Since we were miles from the railroad tracks, I thought nothing of it. But as we topped the hill, the truck was suddenly pulled hard to the right side of the road. I fought the steering wheel and turned to see what was happening. A white tornado was bearing down on us. The tornado had entered a nearby watermelon patch and was sucking up the white sand. Dad yelled, “Don’t look! Floor it!” Yanking the wheel as hard as I could, I reached a spot where the woods and a berm protected us. I slowly regained control of the truck, only to see a watermelon drop down and splat on the road. With the dust swirling, I literally had to dodge watermelons falling from the sky.
Keeping the soil tied to the ground requires more than expecting rain to provide moisture for grass and weeds to grow. A good rancher knows that more grass stubble means more for the livestock to eat and a quicker recovery period once the rain returns. There are many methods to keep grass growing in a drought. Leaving the soil uncovered allows dust to become the rancher’s enemy. Keeping the soil covered is a rancher’s real friend.
David E. Will is a Schulenburg farmer, rancher, nurseryman, landscaper, and consultant. He can be reached at (830) 629-9876 or by email at dwill207@satx.rr.com.