Effects of organic acids on salt precipitation in drip emitters and soil

Three organic acid compounds were evaluated for preventing precipitation of salts and/or removing salts in drip irrigation systems and soils. Three ex periments were conducted to measure drip emitter clogging, ponded infiltrat ion and soil salinity change. All acid compounds included maleic acid, a fo rm of dicarboxylic acid. The first organic acid was composed of polymaleic acid, maleic acid, surfactant blend, and inert ingredients. The second was an anionic polymer with maleic acid as the organic acid. The third included a soap and was a 1:1 stoichiometric equivalent of an organic carboxylic ac id and an amine base. The first and third organic acid significantly reduce d drip emitter clogging compared to a water-only treatment. The third organ ic acid was significantly better than the first for reducing clogging. The third organic acid and water-only treatments significantly reduced the soil sodicity below the drip irrigation laterals during the study. Ponded infil tration tests with organic acid in water were also conducted. All three org anic acid treatments produced significantly lower infiltration rates than t he water-only treatment. This may have occurred because salt precipitates i n the soil were removed and pores were clogged.