Grow More Lint With Less Water

Dan Crummett, Contributor

Ever since Lloyd Arthur and his family decided to downsize their farm to mainly irrigated acres in 2007, the history of their operation has been a study in a drive for better water efficiency. Over the years, the effort has paid off, not only in reduced water consumption but also in significantly better cotton yields.

“My dad would be astounded,” Arthur explains. “I have less water, and, I’m making twice the yields he did.”

PRODUCTIVITY AND TECHNOLOGY

Farming with his brother and son as Arthur Farms and ULL Farms, Arthur says the 2,000-acre operation near Ralls, Texas, is about a third of its size in the early 2000s. But, the operation is producing more cotton with irrigation wells producing at only about 3 gallons per minute per acre flow.

Technology has played a big part in productivity. “Before we cut back, we had three to four employees. Today, we have only one,” he says. ULL Farms is moving away from furrow irrigation, a practice common in Crosby County long after corn producers further north in the Texas Panhandle had dotted the map with sprinkler systems.

Today, the farms operate 10 LEPA-equipped (low-energy precision application) center-pivot sprinklers and seven drip-irrigation systems. Overall, the pivot-to-drip ratio is about 80/20 on the farm, with drip systems ranging in size from 35 to 70 acres in fields where it’s difficult to operate a sprinkler.

The farm operates five quarter-mile center pivots on 160-foot spans, a half-mile on a partial circle and four six-tower pivots that operate up against a four-lane highway.

“We began installing drip acres about the time we downsized and spaced them on 80-inch centers [between every other furrow], which matched the drop spacing on our center-pivot sprinklers,” he says. The last drip system was installed in 2014, buried directly beneath their 40-inch rows. It was an investment that helps Arthur ensure the plants have sufficient water when it needs water more efficiently.

In addition, the Arthurs are moving toward similar water-efficiency boosts with 40-inch spacing on the sprinkler systems. “This past year, we used USDA EQIP [Environmental Quality Incentives Program] funds to replace an aging center pivot and installed the drops on it at 40 inches,” Arthur explains. “Irrigation analysts recommended doing this to put water on both sides of the crop to allow water to infiltrate more quickly with less evaporation.

“We’re comparing that pivot with another one nearby, which still has 80-inch drops watering between every other row. Despite hail damage on the field with the new pivot, I like what I’ve seen. We had taller plants than usual and no rutting, even on sloped ground,” he continues. “Even with the hail, I’m convinced we’ll see 30 to 40 pounds more lint under the 40-inch drops compared with the traditional sprinkler.”

COVER CROPS AND MONITORS

The Arthurs’ move to narrower row spacing of irrigation equipment goes hand in hand with the farm’s increasing use of erosion-controlling, small-grain winter cover crops. Research shows narrower sprinkler drops applying water through crop residue and growing covers significantly increases application efficiency. In many applications across the High Plains, cash grain irrigators are using 30-inch spacing.

“We can’t use covers on all of our farm, but, where we can, we see much better water infiltration and important reductions in wind erosion throughout the winter,” Arthur explains.

One of the best boosts in irrigation water efficiency and one of the biggest surprises to Arthur was the addition of soil-moisture monitors in the sandy loam High Plains soils at ULL Farms.

Over the years, he has used John Deere, AquaSpy and CropMetrics monitors, all of which, he says, do the job and work very similarly; but, he’s currently partial to the CropMetrics system’s ability to report to his cell phone.

“You just dig a hole and install the monitor in the field, and, it uses a phone relay to your computer server, so, you can see in real time the moisture conditions beneath your crop--in the office or on your phone,” he says.

Arthur first used monitors about seven years ago, and, he says the result was eye-opening. “Normally, we had our pivots circling about once every three days. But, once we started monitoring the actual moisture in the profile, we figured out quickly we weren’t pushing that water into the root zone--and, we were still losing a lot of applied water to evaporation,” he says. “It took me visually seeing the monitor results to realize I needed to slow down the sprinklers to get the water deep enough to maintain the plant and protect the water from evaporation. The result was less evaporation and increased yields.”

Arthur says his pivots now run five to seven days making a circle, and, because of better water infiltration at slower sprinkler speeds, the crop doesn’t suffer even on windy, hot July and August afternoons.

“Surprisingly, we found the same technique holds true for our drip acres,” he says. “Before, each total field was getting a small drink every 36 hours, as I thought I had to do that to keep the plants from stressing. What the monitors showed us was even watering like we do now with drip, we stay in each zone of the field no fewer than 24 hours, and, even on hot days, the plants don’t get behind because we’ve supplied sufficient water to the root zone.”

CONSISTENT RESULTS

In a cooperative study with the Texas Alliance for Water Conservation (TAWC), Arthur says one of his drip fields that had consistently produced two-bale cotton yielded three bales.

“On the rest of the farm, I’d estimate we’re getting 50 to 75 pounds of lint extra per acre because of slower, longer water-application rates,” he explains. “It just took putting something underground to see what was going on.”

Labor productivity rose when the Arthurs installed Lindsay’s FieldNET on the majority of their center-pivot rigs to control positioning and irrigation rate plus monitor the operation of their sprinklers via a computer or smartphone.

“The system has shortened our downtime on malfunctioning pivots from three to six hours to 15 to 30 minutes,” Arthur says. “It gives us more time to do other things.

“Before, we’d drive around to check the pivots, and, maybe one would go down 15 minutes after we checked it, and, it would sit there for hours before we knew there was a problem,” he explains. “Now, we know which machine needs attention and go to it first, so, we can get water flowing to the crop again so we can stay on schedule.

“With FieldNET, we can monitor the systems 24/7, and, if a machine stops or a well goes dead, we can go see what’s wrong in a timely manner; and, in late July, that can make a big difference to cotton farmers.”

Arthur says the wireless system has also helped boost water efficiency, because it enables variable-rate application through pivot speed control. “We can speed up the sprinklers when we are in areas of the field where water saturates quickly, then, we can slow it down where we know the water will infiltrate better,” he explains.

Arthur looks forward to results he sees from variable-rate fertigation.

“By spoon-feeding the crop throughout the year with the irrigation systems, we’ve cut back on fertilizer costs,” he says. The Arthurs collect annual and biannual 24-inch soil samples to keep abreast of the crop’s nutrient needs. Based on crop performance and weather conditions, they use fertigation to meet those needs.

“Right now, we can turn the fertilizer pumps on and off remotely, but, we’re eager to try operating those pumps at varying flow rates for the 2019 crop.”

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