FAQs

Honeywell launched the Sulf-N PRO line of ammonium sulfate fertilizers in 2005 after extensive research and test marketing. All Sulf-N PRO products are formulated exclusively for turf at Honeywell's state-of-the art production facility in Hopewell, Virginia.

Honeywell carefully screens Sulf-N PRO fertilizers to meet the precise needs of turf professionals. Mini (SGN 150), micro (SGN 100) and soluble (SGN < 100) grades meet the highest turf industry standards for particle size and uniformity. Mini and micro grades are also treated with a conditioning agent to improve handling.

Agricultural grades of ammonium sulfate have been used on turf for many years, but the granular grades for crop production are becoming too big for turf. Sulf-N PRO fertilizers deliver all of the agronomic benefits of ammonium sulfate in product formulations that are ideally suited for blends and direct application to turf.

Sulf-N PRO ammonium sulfate (21-0-0 24S) contains 21% nitrogen in the ammonium form and 24% sulfur in the sulfate form.

Ammonium sulfate has scored high points for nitrogen efficiency, quality and color ratings in university testing. Additionally, research on turf demonstrates that ammonium sulfate is effective for suppression of soil borne diseases, including summer patch, take-all patch, and spring dead spot.

Contact Honeywell via e-mail at sulfn@honeywell.com or call 1-804-541-9411 or 1-800-446-4834.

Sulf-N PRO ammonium sulfate from Honeywell is a barrel-shaped crystalline granule. It will range in color from light tan to dark brown, depending on various operating conditions at our Hopewell, Virginia production plant.

Yes. Many specialty fertilizer suppliers and distributors have blending capabilities. Sulf-N PRO ammonium sulfate is often an ingredient in these blends. Ask your supplier if they use Sulf-N PRO ammonium sulfate and the grades that contain it.

Sulf-N PRO ammonium sulfate is a versatile plant food material and can be used routinely on home lawns and grounds, sports fields, golf courses, landscape plantings, commercial lawn and grounds, parks and recreational areas, schools, municipal buildings and grounds, and other areas where supplemental nitrogen is needed.

Sulf-N PRO fertilizers have been field tested and are used routinely on both warm and cool season turfgrass species with excellent results.

Sulf-N PRO soluble grade ammonium sulfate (SGN < 100) easily dissolves in water to make a liquid ammonium sulfate solution.

Yes, Sulf-N PRO fertilizers can be used anywhere on a golf course. For dry fertilizer application, choose mini or micro grade according to the height of the cut. For liquid fertilizer application, use soluble grade.

Sulf-N PRO ammonium sulfate is a soluble source of nitrogen. Although it is not classified as slow-release, research demonstrates that the ammonium form of nitrogen in Sulf-N PRO fertilizers often provide a longer lasting green than other soluble N materials. After soils warm to 50 F, a 1 lb N/1000 sq ft application will last approx. 4-6 weeks, depending on weather conditions. Warm season grasses that typically use more nitrogen will require somewhat higher rates.

Yes. Sulf-N PRO fertilizers are compatible with most blend ingredients. Results will be as good as or better with Sulf-N PRO ammonium sulfate, as proven in numerous field trials from around the US.

Yes. The nitrogen in Sulf-N PRO ammonium sulfate is readily available, which makes it an excellent complement to organic N sources, which frequently contain a large percentage of slow release N and a small percentage of soluble N. In fact, research trials have demonstrated that Sulf-N PRO ammonium sulfate produces superior turf quality versus other soluble N sources when blended with organic nitrogen.

Sulf-N PRO soluble grade is recommended for spoon-feeding in order to achieve uniform application at low N rates. It can be used alone or mixed with other nutrients. Sulf-N PRO ammonium sulfate is a soluble source of N, so timely scheduling is important for consistent turf color and quality. Use in combination with a slow release N source if full reliance on spoon- feeding is not desired.

Best results are obtained by applying the material to dry turfgrass and immediately watering in with at least 0.1 inch of irrigation or rainfall.

Research demonstrates that the ammonium form of nitrogen found in Sulf-N PRO ammonium sulfate is less susceptible to environmental N loss through volatilization, leaching and denitrification compared to urea and nitrate forms.

The need for sulfur in turf fertilizers is growing as anti-pollution legislation continues to reduce the amount of "free" sulfur that falls to the earth through acid rain. Like nitrogen, sulfur contributes to photosynthesis and encourages healthier, greener turf. Need for sulfur increases as soil texture becomes more sandy and where organic matter levels are lower (< 3%).

Yes. In turf trials, ammonium sulfate consistently improves turf color for several reasons. First, nitrogen is the single most important nutrient that contributes to turf color. The ammonium form of nitrogen in Sulf-N PRO ammonium sulfate is less prone to environmental losses to leaching, volatilization and denitrification. As a result, more N is often retained in the root zone and available for plant uptake. The ammonium form of nitrogen also improves uptake of phosphorus, manganese and iron - three nutrients that are also associated with desirable turf color. Finally, Sulf-N PRO ammonium sulfate contains readily available sulfur, which also contributes to development of turf color.

When used as the sole nitrogen source, research demonstrates that ammonium sulfate is 1.5 to 2 times more acidifying to the bulk soil than other nitrogen materials. When Sulf-N PRO ammonium sulfate is used as one component in an overall nitrogen management program, the effect on soil pH is negligible. As with any nitrogen program, best management calls for routine monitoring of soil pH and liming as needed.

Sulf-N PRO ammonium sulfate temporarily reduces pH in the area surrounding turfgrass roots, also known as the rhizosphere. This is different from bulk soil acidification and offers several benefits: First, research demonstrates that low rhizosphere pH enhances absorption of phosphorus and important micronutrients like manganese and iron. Second, research suggests that low rhizosphere pH also accounts for why ammonium sulfate fertilizers like Sulf-N PRO ammonium sulfate suppress common soil borne diseases like summer patch, take-all patch, and spring dead spot.

Yes. Research demonstrates that ammonium sulfate suppresses important turfgrass diseases, specifically summer patch in bluegrass, take-all in bentgrass and spring dead spot in bermudagrass. Depending upon the severity of the disease, other disease management actions may be necessary, including use of fungicides and/or other cultural practices.

There is some research that indicates ammonium sulfate may suppress dollar spot.