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Abstract
Zhang, M., S.
Sparrow, P.J. Bechtel, A. Pantoja. 2007. Characteristics
of nitrogen and phosphorus release from fish meals
and fish hydrolysate in subarctic soils.
JEMREST 3:262-275.
DOI: 10.4029/2007jemrest3no130
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 produced from the Alaska fishing industries. These fish by-products are rich in nitrogen
and can be processed and used as a nutrient source for crop production. 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 whitefish
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 byproducts
at 100 µg 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 and analyzed for mineral N and Melhich 3 P. Single exponential models were used to
simulate mineral N release. The
results showed that the cumulative mineral N release of each of the three
fish byproducts 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
byproducts. There was very little P
release over the course of incubation.
The single exponential model was suitable for simulating N release for
fish meals, and that was validated by the field incubation results.
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