Evaluation of Ammonia Recovery from a Laboratory Static Diffusion Chamber System

ABSTRACT

Ammoniacal fertilizers are susceptible to ammonia (NH₃) volatilization, and multiple methods have been introduced to quantify loss. Methods to quantify differences in NH₃ loss are important for evaluating the effectiveness of treatments. Recent research hypothesized that opening chamber enclosures resulted in nitrogen (N) loss (16–30%). Thus, the recovery efficiency of static diffusion chambers used in laboratory experiments was investigated. Chambers with a sand–calcium carbonate (CaCO₃) mixture received ammonium-N (NH₄-N) solutions. Three time intervals were used to determine if variation in enclosure opening influenced recovery. Acid trap percent recovery and a mass balance approach were used. No differences in cumulative NH₃ volatilization were measured from either acid traps or using a mass balance approach. No differences were measured in percent recovery based on N application rate, sample interval, or their interaction, and mean percent N recovery was 99.0%. Thus, diffusion chambers can be reliably used to measure differences in NH₃ volatilization.

KEYWORDS:

• Ammonia
• diffusion chamber
• volatilization