Nitrogen Mineralization of Bee Frass.

Honey bee feces (frass) have high concentration of uric acid, which may mineralize rapidly in soil. This study was conducted to evaluate nitrogen (N) mineralization and ammonia volatilization from bee frass when surface applied or incorporated into soil. Treatments were: 1) control (no frass), 2) frass added after water addition (simulating frass deposition after rain) and 3) frass added before water addition (simulating frass deposition before rain).  All treatments were arranged in a completely randomized design with four replications. Experimental units were placed in a flow-through system in an incubator set at 25^oC so that volatilized ammonia could be collected in acid traps. Samples were extracted at 15, 30, and 45 d for inorganic N determination. There were no differences between the two treatments of rain simulation time. Mineralized organic N in 45 d averaged 21% and volatilized ammonia was less than 1% of applied frass N. These results indicate that a significant fraction of bee frass N may become available to plants soon after deposition.