|Zhang, M. - UNIVERSITY OF ALASKA|
|Sparrow, S. - UNIVERSITY OF ALASKA|
Submitted to: Journal of Environmental Monitoring and Restoration
Publication Type: Abstract Only
Publication Acceptance Date: April 5, 2007
Publication Date: N/A
Technical Abstract: The expanding of organic farming in Alaska demands alternative nutrient sources for crop production. Annually, there are over 1,000,000 metric tons of fish by-products from the Alaska fishing industries. These fish by-products are rich in nitrogen and can be processed and used for crop production fertilizers. The first objective of the research was to determine rates of N and P release from 1) protein hydrolysate made from salmon by-products; 2) commercial fish meal made from Alaska pollock by-products; and 3) commercial fish bone meal made from Alaska by-products. The second objective was to develop simulation models for predicting fish meal N release in the field. Incubation experiments were conducted in the laboratory and the field. Two soils with or without fish products at 100 ug N g-1 soil were incubated at 10 and 15oC for 56 days in the laboratory, or placed in plastic bags and incubated in two field locations. Soil samples were taken during the incubations. Mineral N and Melhich 3 P were analyzed. Single exponential models were used to simulate mineral N release. The results showed that the cumulative mineral N release of three fish products followed a typical two-stage release pattern, i.e. a fast release phase until 7 days followed by a slow release phase. In the laboratory the amount of mineral N released in 56-day incubation was similar among the three fish products within soil treatment; however, the nitrification rate was faster in one soil treatment than the other. There was very little P release over the course of incubation. The single exponential models were suitable for simulating N release for fish meals, and that was validated by the field incubation results.