Potentials of nitrification inhibitors in modern N‐fertilizer management

Abstract Modern agricultural practices require a new concept of N‐fertilizer management in order to optimize N‐utilization and avoid N‐losses. Nitrification inhibitors or „N‐stabilizers”︁ fit very good into this conception. Dicyandiamide (DCD) is an efficient nitrification inhibitor and blocks the first step of nitrification for 1–3 months (depending on temperature). This effect is bacteriostatic (not bactericidal) and does not affect other (esp. C‐heterotrophic) soil microorganisms („biological activity”︁). DCD is a non‐toxic, water soluble compound and will be degraded to CO2, NH3 and H2O without any residues. There are various possibilities to use DCD: addition to liquid manure temporarily prevents oxidation of ammonium nitrogen e.g. of slurry or waste water from potato starch production. In combination with inorganic fertilizers like ammonium sulfate or urea (with 10% of total‐N) it enables the farmer to control NH4‐supply to crop plants in certain stages of growth and to gain certain operational advantages by less frequently split applications of N especially on sand and rendzina soils. Thus, the systematic use of nitrification inhibitors not only represents a progress in agricultural technique but also helps to substantially reduce risks concerning pollution of surface and ground waters that are sometimes inevitable consequences of agricultural production.