Effects of the Novel Nitrification Inhibitor Dmpsa on Yield, Mineral N Dynamics and N2O Emissions.

Sustainable use of nitrogen (N) fertilizers is essential for agronomic efficiency and environmental stewardship. In order to achieve this nitrification inhibitors (NI) can play an important role in mitigating unwanted environmental impacts by N fertilization, i.e. nitrate leaching and greenhouse gas (GHG) and nitrous oxide (N₂O) emissions, while sustaining and increasing yields. A new nitrification inhibitor 2-(3,4-dimethyl-1H-pyrazol-1-yl) succinic acid isomeric mixture (DMPSA) has been developed and is characterized by a slower reagent release curve and different physicochemical properties as compared to established inhibitors (e.g. DCD, nitrapyrin, DMPP). In recent years, the new inhibitor was evaluated in laboratory and field trials regarding yields, N uptake and N₂O emissions in different environments and combined with varying fertilizers (e.g. urea, CAN, AS) and crops (arable crops, vegetables, fruits). DMPSA was proven to reduce N₂O emissions from urea and CAN by 60-90% as compared to the untreated fertilizer in both incubation and field trials. On the tested fertilization levels yields and N-uptake were mainly unaffected or slightly increased by application of DMPSA, on average +4% and +2% for yield and N-uptake, respectively. The effect of DMPSA appeared to be independent of the N fertilizer type combined with the compound and crop type. The application of the new compound could still be further improved by reducing fertilization levels sustaining the same yield and N uptake level and varying fertilizer management by reducing the number of split N applications. Additional options for an optimized fertilizer N management by use of DMPSA require further investigation.

Key Words

Nitrification inhibitor, DMPSA, incubation, N₂O, urea, CAN, yield