To anyone unacquainted with agriculture in the western states, putting sulfuric acid on a crop might sound like agronomic suicide. Then again, who would have imagined 20 years ago that tractors would someday drive themselves with the aid of satellite guidance? As science and technology have advanced, so, too, has agriculture.
According to Tim Lowry, West Coast sales representative for Agri-Inject, the practice of injecting acids to irrigation water to balance high water pH levels has been going on in parts of California and the West for at least 30 years. However, it’s only been in the past five to seven years that the practice has been moving east.
Already, parts of Texas and certain areas on the East Coast have found that injecting acid into the irrigation water has helped increase both water infiltration and nutrient availability.
It all started back in the 1970s when MCDS (moncarbamide dihydrogen sulfate) started to find its way into the golf and agricultural markets. Labeled as 15-0-0-16s, 49 percent sulfuric acid, it was originally targeted to the golf industry, since that’s where problems were most prevalent, due in part to the inability to disc or plow turf soils.
As a general rule, soil mimics the water that runs through it, which means alkaline water makes alkaline soil. Water with high amounts of bicarbonates will precipitate calcium. When high bicarbonate water reaches the soil, the calcium can be removed from the soil particle. Sodium can then take the calcium’s place at a rate of two sodium ions to every one calcium ion. In this way, a calcium-dominant soil can become a sodium-dominant soil by the use of high bicarbonate irrigation water.
DCDS (dicarbamide dihydrogen sulfate) 28/27 (28-0-0-9, 27 percent sulfuric acid) is well-known in the golf industry for being the perfect nitrogen. The 28 percent nitrogen is more of a controlled-released nitrogen, which adds oxygen to the water and soil. In effect, it’s an acidic, it’s an oxidant, it’s root and foliar absorbed, it’s stable in saline water, and it has an impact on disease and microbes.
As Lowry relates, the obvious reason for using an Agri-Inject system to add an acid formulation to irrigation water is to reduce the pH of water. The better reason, however, is to gain the benefits that come with acid injection. The practice not only alters the chemical composition of the water; it reduces the sodium adsorption ratio and creates better water percolation. Acid injection can also increase fertilizer performance, enhance the effectiveness of alkaline-sensitive pesticides, and improve overall soil quality.
“One to two decades ago, it was more common to use acid injection just to balance out the pH and to reduce the problems with calcium buildup in like the sprinkler heads,” Lowry says. “However, research has since shown us that there are other benefits. “Your average water pH in some of the West Coast states runs from the mid- to high-7s to an average that falls between 8.2 and 8.8 in some areas. So they try to buffer it with a variety of different acid sources.” Lowry notes that there are now a number of different manufacturers offering everything from urea-based acid to phosphoric-based acid.
Lowry notes that even though most Agri-Inject units can be used for acid injection, particularly the fertilizer injection units, he says it’s always best to have the pump converted to “acid-ready” by having the factory change out some of the components with acid-resistant alloy 20 material.
“The 316 stainless steel that we use on the conventional pumps will hold up for a while with acid,” he says. “But for long-term usage, [it’s best to install] alloy 20 heads.”
Lowry says that as water restrictions becomes more prominent and various areas experience drought, affected producers are realizing that they can get more bang for their buck by adding an acid blend to their irrigation water, particularly if the water or soil has a high pH.
“In California, for example, the only way you can offset a reduction of water is to make your water perform better for you,” he relates. “If you acidify the water, you get better water filtration and a reduction in the sodium adsorption ratio.
With these extra benefits working their way into your soil, you will also start to see a better uptake of the fertilizer you are currently using.”
Of course, the only way to know if acid injection will be beneficial to your operation is to have a professional determine the soil pH and perform a water analysis to determine the level of bicarbonates and sodium. In a growing number of cases, adding an acid formulation to the irrigation water—as crazy as it may sound—could provide unforeseen benefits.