Cotton pioneer 'at it again'

By Lana Robinson
Field Editor

Hubert Frerich of Garden City was an early proponent of the subsurface drip irrigation (SDI) systems that have transformed the St. Lawrence region of West Texas and are currently expanding around Abernathy, Levelland and other points in the South Plains. Now, he's focusing on another revolutionary technology he believes will lower soil pH and boost cotton yields.

"I've installed a sulfur burning acid system," says Frerich, a spry septuagenarian whose visionary instincts have earned him the respect of agricultural producers, experts and agribusiness leaders throughout the state. "Generally speaking, this technology is used to lower water pH in areas where farmers have a bacterial problem. I began noticing about five years ago that wherever I went, crops with the sulphur machine on it always did better. I began to explore why and discovered that the treated water really helps make more nutrients available. I became more and more interested in it from an agronomic standpoint."

Frerich notes that area farmers have already been using sulfuric acid and infuric acid for this purpose, but it's quite expensive, and the sulfuric acid can only be transported by someone with a CDL license. Some other cotton producers apply sulfur directly to the soil. But the results are often slow coming.

"The neat thing about this is the burner creates an SO2 gas, which is injected into the water and it has an immediate effect," says Frerich.

According to the manufacturer of the patented technology, Sweetwater International, the acidifier has several uses, including: 1) to reduce salts in irrigation water used for agriculture and golf courses; 2) to reclaim agricultural land that is high in carbonate, bicarbonates, slats or calcium carbonate; to encourage growth of low-pH crops such as corn, soybeans, potatoes, cirtus fruits, sugarcane, beans, tomatoes, berries, and tea; to reduce the pH of irrigation waters and soils while providing an important plant nutrient (sulfur) in readily absorbed form; and 4) to dechlorinate effluent from water treatment plants before it is released into natural streams or used for irrigation.

Calcarious soils often occur in combination with problems of salinity and sodicity. Because excess calcium carbonate reduces soil permeability and leaching capacity, it may contribute to the build-up of salinity and sodicity from irrigation water.

"We have alkaline soils here. We keep adding alkaline to our soil and building up a higher pH yet with irrigation water. Microorganisms and phosphorous are not available to the plant. It's helping to release that. If we can lower that pH, it will help dissolve salts. That's sodium chloride—a bad one. And there are plenty of others, like calcium chloride and manganese, that are referred to as salts," he explains.

Calcium carbonate (lime), when it occurs in excess, is a cementing agent that ties up nutrients and impedes the movement of water and the development of root systems. Impermeable crust on the surface may contribute to runoff and lack of water infiltration. Hardpan or "caliche" layers below the surface act as thick, physical barriers through which roots and water may not pass, limiting plant growth and making leaching impossible.

"By treating these salts, when you get a rain or water the crop, it starts moving to the soil," he explains.

In short, the SAG unit is comprised of three sub-systems: 1) the hopper in which sulfur is stored and from which it is fed into 2) the burning chamber, where sulfur is burned to create sulfur dioxide gas which is subsequently introduced into a stream of irrigation water in the 3) absorption system, creating sulfurous acid and sulfuric acid. This diluted acidic solution is then released into the main stream of irrigation water.

The SAG is clean burning, operates with water pressures as low as 1 psi or as high as 10 psi, and requires no electricity. It's a low-maintenance design with no moving parts.

Frerich is so convinced that the system will produce positive results, he installed it on his own cropland, which he has leased to a tenant.

"I developed and modified it to where it's pretty darn efficient," Frerich says of his own system. "I've only had it going during the season. Next year, I plan to pre-irrigate, to help leach it before the crop goes into the ground."

Warren Multer, Glasscock County IPM agent, says Frerich's "experiment" goes right along with some of the studies underway in the region.

"Right now, we're looking at a study on salinity management—saline water," says Multer. "We're also looking at a study on phosphorous fertilizer on drip irrigation. There was a study done in years past on furrow that indicated there was not much benefit from phosphorous, but now we are looking at it on drip. We feel like having the tape in the same place all the time, and not deep plowing, we are mining all the phosphorous out of the root zone. We are seeing some pretty big results. By applying 250 lbs. per acre, we can increase the yield by $120 per acre. That's 30 cents even on 50-cent cotton and that's with $20 of fertilizer."

Multer agrees that the water pH is pretty high (7.6 to 8.2) and adding sulfur should make more nutrients available to the crop.

"It will help rainwater to penetrate the surface faster. We've known for years that if you put in new land, or didn't irrigate, you always made a better crop the first several years. Over time, the salts in water pickles the ground. The sulfur will help get rid of those," says Multer.

Multer credits Frerich with having introduced subsurface drip irrigation to the region in 1984 and successfully nurturing the concept to widespread use. He says the efficiency of the system has been valuable with rising electric costs and other costs associated with growing and irrigating cotton.

Rainfall in the region averages between 10-15 inches in good years, but that has dropped to 6 inches in the past few years. Also, water well yields are very low, typically 35 gallons per minute. Growers usually tie about six wells together with a goal of being able to provide a reliable volume of irrigation water. Thus, the conversion from furrow to drip irrigation with its frequent application of small amounts of water had a dramatic impact on the region's cotton yield and quality. Multer says, for the most part, growers opt for the least expensive drip tubing/tape product available.

Alternate row irrigation is another practice adopted by farmers here. Alternate row irrigation of cotton has received much attention by Texas researchers since it improves yields under all forms of irrigation throughout West Texas. Enhanced yield potential is not the only advantage of SDI. The system has allowed some farmers to go to minimum tillage, which substantially reduces labor and machinery costs and wear and tear on equipment.

Multer estimates cotton acreage under subsurface drip irrigation in the St. Lawrence area at 35,000.

"We're probably going to get more in due to the cost share with EQIP (Environmental Quality Incentives Program, reauthorized with the 2002 farm bill)," Multer predicts.

"The trend for installing drip irrigation has been up every year for the past 10 years," says Frerich.