We all know the saying about having our cake and eating it too, but did you know that with SUL4R-PLUS® fertilizer products it is true as well? SUL4R-PLUS fertilizer provides a very soluble and available sulfate, immediately available to the plant in the form that the plant needs for uptake. Yet a new study by Texas A&M AgriLife Extension, under direction Jake Mowrer, PhD, has shown that SUL4R-PLUS fertilizer does not leach like ammonium sulfate and other sulfate forms!
SUL4R-PLUS fertilizer is available not only in the form the plant needs, but when the plant needs it. It makes sense to use SUL4R-PLUS products on your crops!
Executive Summary: A controlled laboratory study was performed to investigate the potential for sustained release of sulfur from SUL4R-PLUS®, a patented pelletized calcium dihydrate (gypsum) product, ammonium sulfate, and elemental sulfur as sulfur-containing fertilizer sources. Three soils of contrasting chemical and physical properties representing important agricultural niches in Texas received fertilizer from each source listed above at low and high rates of equivalent sulfur concentrations. The three soils (1 kg each) were packed into columns to a bulk density of 1.5 g cm-3 and leached at nine intervals over a 60-day period. Leaching water volumes applied were adjusted for each soil according to the relative pore space available. Leached water was collected from the bottom of each soil column and analyzed for plant available sulfate-sulfur (SO4-S). Results indicate that ammonium sulfate released all applied fertilizer sulfur as plant-available, but also potentially leachable, sulfur within the first 5 days. Elemental sulfur applied to the soils released no appreciable amounts of plant-available sulfur over the entire duration of the study. SUL4R-PLUS®, however, released a moderate amount of sulfur over the initial 10 days of the study, and continued to release between 2 to 5 lbs per acre, depending on the rate applied, of plant available sulfur every 10 days thereafter. SUL4R-PLUS® demonstrated a statistically significant potential to provide sustained release of SO4-S throughout the growth cycle of a crop plant, while protecting applied nutrient sulfur from losses due to early uncontrolled release and subsequent leaching below the root zone. Of the three sulfur-containing fertilizer sources evaluated in the study, the pattern of sulfur release from SUL4R-PLUS® best mimicked the sustained need of crop plants for sulfur nutrition over the course of a growing season.