Portal de Periódicos da CAPES

Effect of the nitrification inhibitor 3,4-dimethylpyrazole phosphate (DMPP) on N-turnover, the N2O reductase-gene nosZ and N2O:N2 partitioning from agricultural soils

2020; Nature Portfolio; Volume: 10; Issue: 1 Linguagem: Inglês

10.1038/s41598-020-59249-z

2045-2322

Johannes Friedl, Clemens Scheer, David Rowlings, Evi Deltedesco, Markus Gorfer, Daniele De Rosa, Peter Grace, Christoph Müller, Katharina Keiblinger,

Soil and Water Nutrient Dynamics

Abstract Nitrification inhibitors (NIs) have been shown to reduce emissions of the greenhouse gas nitrous oxide (N 2 O) from agricultural soils. However, their N 2 O reduction efficacy varies widely across different agro-ecosystems, and underlying mechanisms remain poorly understood. To investigate effects of the NI 3,4-dimethylpyrazole-phosphate (DMPP) on N-turnover from a pasture and a horticultural soil, we combined the quantification of N 2 and N 2 O emissions with 15 N tracing analysis and the quantification of the N 2 O-reductase gene ( nosZ ) in a soil microcosm study. Nitrogen fertilization suppressed nosZ abundance in both soils, showing that high nitrate availability and the preferential reduction of nitrate over N 2 O is responsible for large pulses of N 2 O after the fertilization of agricultural soils. DMPP attenuated this effect only in the horticultural soil, reducing nitrification while increasing nosZ abundance. DMPP reduced N 2 O emissions from the horticultural soil by >50% but did not affect overall N 2 + N 2 O losses, demonstrating the shift in the N 2 O:N 2 ratio towards N 2 as a key mechanism of N 2 O mitigation by NIs. Under non-limiting NO 3 − availability, the efficacy of NIs to mitigate N 2 O emissions therefore depends on their ability to reduce the suppression of the N 2 O reductase by high NO 3 − concentrations in the soil, enabling complete denitrification to N 2 .