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
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.