Evaluation of Two Products Recently Introduced as Nitrification Inhibitors

ABSTRACT

This study compared the relative effectiveness of two products recently introduced as nitrification inhibitors with other materials used to inhibit nitrification. Four soils were treated with 0, 0.2, 1, 5, and 25 mg kg⁻¹ of nitrapyrin (NP), a new microencapsulated nitrapyrin product (ENP), dicyandiamide (DCD), a new maleic-itaconic polymer product (MIP), and ammonium thiosulfate (ATS). The soils were also treated with 200 mg N kg⁻¹ as urea, and percent inhibition of nitrification determined after 2 or 4 weeks of incubation. After 4 weeks, similar levels of nitrification inhibition were provided by 1 mg kg⁻¹ of NP (72%), 5 mg kg⁻¹ of ENP (79%), and 25 mg kg⁻¹ of DCD (73%), averaged across soil. After 4 weeks with a sandy soil, the highest rate of MIP and ATS provided 15 and 36% inhibition, respectively. MIP and ATS were ineffective at inhibiting nitrification when added to the other three soils.

Abbreviations: ATS: ammonium thiosulfate; DCD: dicyandiamide; ENP: encapsulated nitrapyrin; MIP: maleic-itaconic polymer; NP: nitrapyrin; UAN: urea-ammonium nitrate liquid fertilizer

KEYWORDS:

• Nitrification
• nitrification inhibitor
• nitrapyrin
• N-Serve
• Instinct
• maleic-itaconic polymer
• Nutrisphere-N
• dicyandiamide
• ammonium thiosulfate

Acknowledgments

The author thanks Alan Schlegel for providing the Ulysses soil, and Dow Agrosciences, Specialty Fertilizer Products, and Tessenderlo-Kerley for providing samples of their products.

Disclosure statement

The author declares no conflict of interest.

Notes

1. Dow Agrosciences, Indianapolis, IN.

2. Verdesian Life Sciences, Cary, NC.

3. Dow Agrosciences, Indianapolis, IN.

4. Dow Agrosciences, Indianapolis, IN.

5. Specialty Fertilizer Products, Leawood, KS.

6. Tessenderlo-Kerley, Phoenix, AZ.

7. Koch Agronomic Services, Wichita, KS.

Additional information

Funding

This work was supported by the North Dakota Agricultural Experiment Station and by the USDA National Institute of Food and Agriculture, Hatch project number ND02371;North Dakota Agricultural Experiment Station and USDA National Institute of Food and Agriculture [Hatch project number ND02371].