Application of Nitrapyrin with Banded Urea, Urea Ammonium Nitrate, and Ammonia Delays Nitrification and Reduces Nitrogen Loss in Canadian Soils

Abstract

• Nitrapyrin has been tested in fallow field trials in cereal and oilseed growing regions of Canada.• Nitrapyrin maintained N in the ammonium form through critical loss periods.• Nitrapyrin preserved more mineral N in the soil relative to non-stabilized fertilizer. AbstractSoil N loss is a significant impediment to maximizing yield and profitability for farmers in Canada. Maintaining N in the stable and plant-available NH 4 + form via use of nitrification inhibitors limits the potential for soil N losses from denitrification or leaching. Between 2013 and 2015, twenty-one research trials were established across the major cereal and oilseed growing regions of Canada to evaluate the efficacy of two commercially available formulated nitrapyrin products, eNtrenchTM and N-Serve, at stabilizing soil N in the NH 4 + form and protecting against N loss. Urea, urea ammonium nitrate (UAN) or NH 3 fertilizer treatments were banded in the fall or spring on fallow land, and the soil was sampled to a depth of 60 cm at multiple time intervals after application. Fall applications of nitrapyrin resulted in 21-63% more NH 4 N, and 10-19% more total mineral N, at spring sampling after soil thaw relative to non-stabilized fertilizer. Spring applications of nitrapyrin resulted in larger pools of NH 4 -N for at least 8 weeks after treatment, and they increased total mineral N by up to 25%, compared with non-stabilized treatments. Results suggest that eNtrench and N-Serve are useful tools for growers looking to protect their N investment, optimize crop yield potential, and enhance flexibility of their N application timing.

pH rather than nitrification and urease inhibitors determines the community of ammonia oxidizers in a vegetable soil

“…The concentrations of NO 3 − -N in the soils of urea + nitrapyrin treatment across the pH gradient at day 28 were lower than those in the soils of urea treatment at corresponding pH levels, and the net nitrification rates in the soils of urea + nitrapyrin treatment across the pH gradient were also lower than those in the soils of urea treatment (Table 1), indicating that nitrapyrin inhibited nitrification and its inhibitory effect varied with soil pH. This is consistent with the finding reported previously (Hall 1984; Chancy and Kamprath 1982; Degenhardt et al 2016; Sims and MacKown 1987; Touchton et al 1979; Hendrickson and Keeney 1979). For example, (Hendrickson and Keeney 1979) found that the inhibitory efficiency of nitrapyrin increased with soil pH.…”

Soft Red and White Winter Wheat Response to Input‐Intensive Management

“…Nitrification inhibitors {e.g., nitrapyrin [2-chloro-6-(trichloromethyl) pyridine]} can be added with urea or UAN to inhibit the conversion of NH 4 -N to NO 3 -N, thereby reducing the risk of leaching and/or denitrification and allowing larger quantities of N to remain in the root zone (Warncke et al, 2009;Trenkel, 2010). In Canada, spring urea-based fertilizer applications containing nitrapyrin resulted in larger pools of NH 4 -N for at least eight weeks after treatment and increased total N by 25% as compared with untreated N fertilizer (Degenhardt et al, 2016). Rao (1996) and Mohammed et al (2016) observed a 7 to 24% and 5 to 17% increase in wheat yield, respectively, following incorporation of nitrapyrin onto urea-based fertilizers.…”

Adsorption of nitrification inhibitor nitrapyrin by humic acid and fulvic acid in black soil: characteristics and mechanism

“…1 To date, it has been widely studied and applied in agricultural production. [2][3][4][5][6] The effectiveness of nitrication inhibitors can be affected by soil clay composition, soil organic matter, pH, temperature, soil moisture content and soil microorganisms. [7][8][9][10] Soil organic matter is one of the important factors affecting the effectiveness through the adsorption of nitrication inhibitors.…”