The approach relies on physical and organic nutrient protection rather than chemical inhibitors, allowing plants to access nitrogen and phosphorus gradually while reducing runoff into groundwater.
Coated Mineral Fertilizers Reduce Nitrogen Leaping
Lukas Streit, a farmer managing 50 dairy cows and 30.5 hectares of land in Erlen, Thurgau, applies protected mineral fertilizers to his maize, winter wheat, and fodder beet crops. According to Andreas Kappeler, product manager at Timac Agro, the fertilizer utilizes a blend of ammonium sulfate and urea encased in a limestone mantle rather than chemical nitrification inhibitors.
«The plant has to work to get to the nitrogen,» Kappeler states, explaining that acids released by plant roots dissolve the limestone shell to release nutrients gradually. Along with ammonium and urea, the product contains oligosaccharides to stimulate soil microorganisms, aminopurines to strengthen root systems, and sulfur to support nitrogen uptake.
Because the nutrients release slowly over time, Streit notes that application timing is more flexible. «I no longer have to wait for summer precipitation, but can fertilize when there is still rain,» he says. By applying 3.5 kilograms of Timac Agro’s Sulfammo across two passes instead of 6.5 kilograms of calcium ammonium nitrate in three passes on his wheat, Streit achieves equivalent yields and grain quality while lowering overall input volumes.
Phosphorus Availability and Organic Combinations
To address phosphorus management, the fertilizers use organically bound phosphate that remains water-soluble and plant-available across varying soil pH levels, according to Timac Agro. Manufacturer data indicates that protected nutrients allow for a 20 to 30 percent reduction in nitrogen applications and a 50 percent reduction in phosphorus without sacrificing crop performance.
Streit pairs these mineral products with farmyard manure and slurry. He applies 35 to 40 cubic meters of slurry per hectare to maize following grass-clover rotations or catch crops, alongside plowed-in manure. For his grasslands, Streit uses lime enriched with sulfur and magnesium based on soil test results, applying slurry in early spring and autumn to maintain robust forage stands.
Under-Root Placement and Efficiency in Thurgau
Jan Hug, a contractor and farmer in Kesswil, Thurgau, uses similar protected nutrient strategies for maize, barley, wheat, potatoes, and sugar beets. Hug utilizes under-root fertilization—such as Locaboost NP 15/20—to place nutrients directly near developing root systems.
«I’ve been doing this for over ten years, and root burn has never been an issue,» Hug reports, noting that sugar beets benefit from faster early growth through targeted placement. By applying 150 kilograms per hectare of protected fertilizer under maize, Hug matches the yields he previously achieved with 200 kilograms per hectare.
As regulatory scrutiny over water quality intensifies, adopting precision application methods and controlled-release fertilizers offers a viable path toward lower environmental losses and sustained farm productivity.
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