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ARS Home » Pacific West Area » Kimberly, Idaho » Northwest Irrigation and Soils Research » Research » Publications at this Location » Publication #384211

Research Project: Improving Management Practices for Irrigated Western Cropping and Dairy Systems to Contribute to Sustainability and Improve Air Quality

Location: Northwest Irrigation and Soils Research

Title: Ammonia volatilization from fertilizer sources on a loam soil in Idaho

item DARI, BISWANTH - Oregon State University
item Rogers, Christopher

Submitted to: Agrosystems, Geosciences & Environment
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 6/14/2021
Publication Date: 7/15/2021
Citation: Dari, B., Rogers, C.W. 2021. Ammonia volatilization from fertilizer sources on a loam soil in Idaho. Agrosystems, Geosciences & Environment. 4(3). Article e20192.

Interpretive Summary: Research was conducted for multiple fertilizer sources in Idaho to determine which were most effective at reducing gas losses of N as ammonia. The study was conducted at the University of Idaho Aberdeen Research and Extensions Center, Aberdeen, ID on a loam soil. Urea, ammonium sulfate, ammonium sulfate nitrate, and NBPT-treated urea (NBPT is an established compound applied to urea fertilizer to reduce N losses as ammonia) were tested in the study as well as tillage. Results from the study indicated that the most volatilization occurred for the surface applied urea treatment where all tilled fertilizer applications as well as the surface applied ammonium sulfate, ammonium sulfate nitrate, and NBPT-treated urea reduced ammonia volatilization as compared to untreated surface applied urea. This data is important for crop producers to understand best management practices for nitrogen-fertilizer applications to maximizing agronomic and economic returns while minimizing environmental impacts.

Technical Abstract: Optimizing crop nitrogen (N) uptake while minimizing ammonia (NH3) volatilization from N-fertilizer sources is a critical part of agricultural best management practices. Urea is the most widely used N-fertilizer but also one of the most susceptible to losses as NH3. Fertilizer source and additives can be used to reduce NH3 volatilization. Specifically, urease inhibitors e.g., N-(n-butyl) thiophosphoric triamide (NBPT) can reduce NH3 volatilization from urea. Novel fused ammonium sulfate nitrate (ASN) products have recently been developed as another potential alternative N-fertilizer source but have not been studied widely. A field study was performed to quantify NH3 volatilization from the newly available ASN fertilizer as compared to various N-fertilizers (ammonium sulfate (AS) and urea) including urea treated with the urease inhibitor NBPT in an alkaline calcareous loam soil in Idaho. Further, we assessed NH3 volatilization from surface applied and incorporated N-fertilizers from these various N sources. Untreated surface-applied urea volatilized the highest amount of NH3, whereas incorporation of N-fertilizers was effective in reducing volatilization as compared to untreated surface applied urea. Our study indicated that the N-fertilizer sources (AS, ASN, and Urea-NBPT) were equally effective in reducing NH3 volatilization when compared to surface applied urea. Our study will help refine N-fertilize management under multiple field situations and traditional management practices of crop producers in the western United States. Further, site-years and study locations would be needed to provide evidence of the effectiveness of ASN in reducing NH3 volatilization under a wider range of soil and environmental conditions.