Effects of Combined Nitrification Inhibitors on Nitrogen Transformation, Maize Yield and Nitrogen Uptake in Two Different Soils

ABSTRACT

Nitrification inhibitors (NIs) affect nitrogen (N) cycle and crop yield, but how the combinations of NIs influence N transformation and maize yield remains unclear. An outdoor pot experiment was performed to explore the effect of three NIs (nitrapyrin (CP), 3, 4-dimethylpyrazole phosphate (DMPP) and dicyandiamide (DCD)) and their combinations on mineral N transformation, yield and N use efficiency (NUE) of maize in a brown soil and a cinnamon soil from northeast China. Higher yield and NUE were obtained in the brown soil than that in the cinnamon soil. All treatments with NIs significantly increased NH₄+-N content, grain yield and NUE in both soils, especially for NIs combination (DMPP + DCD in the brown soil and CP + DCD in the cinnamon soil). These two treatments significantly increased yield and apparent nitrogen recovery by 1.84 and 2.31 times, 10.24 and 6.39 times, respectively, compared with N fertilizer treatment. They also showed lower apparent nitrification rates (17.2% and 53.7%, respectively) compared with single NIs treatments. Considering both the inorganic N supply and agronomic effect of NIs, DMPP + DCD and CP + DCD are the best strategies for the application of NIs in the brown soil and cinnamon soil.

KEYWORDS:

• Ammonium nitrogen
• nitrification inhibitors
• nitrate nitrogen
• nitrogen use efficiency
• yield

Acknowledgments

We are grateful to the National Field Research Station of Shenyang Agroecosystems, Chinese Academy of Sciences, for providing the experimental field. We also acknowledge Timothy A. Doane for proofreading assistance.

Disclosure statement

No potential conflict of interest was reported by the author(s).

Additional information

Funding

This work was supported by the National Key Research and Development Program of China under Grant [number 2017YFD0200707]; the National Scientific Foundation Project of China under Grant [number 31971531] and the National ScientificFoundation Project of under Grant [number 41807388].