Submitted to: American Ecological Engineering Society Conference
Publication Type: Abstract Only
Publication Acceptance Date: June 15, 2003
Publication Date: July 1, 2003
Citation: WESTHEAD, E.K., PIZARRO, C.X., MULBRY III, W.W., SIKORA, L.J. RECYCLING OF MANURE NUTRIENTS: USE OF DRIED ALGAE AS AN ORGANIC FERTILIZER. American Ecological Engineering Society Conference. 2003.
The vulnerability of aquatic ecosystems and groundwater to nutrient pollution has forced increasingly stringent environmental regulations to be placed on dairy farms. Production of algae on wastewater nutrients could provide a holistic solution to nutrient management problems on existing farms. Algal biomass recovered from such systems has a variety of potential on- and off-farm uses. Although it has primarily been considered as an alternative high-grade protein source in animal feed, algal biomass with a balanced N:P ratio is a potentially valuable organic fertilizer. It may also have some biocontrol properties. The objective of this study was to evaluate the use of dried algal biomass as an organic fertilizer. Soil mineralization tests revealed that approximately 30% of algal nitrogen (N) was converted to plant available N within 21 days at 25 C. Results from cucumber plant growth studies using potting mixes amended with dried algae showed that 19 day-old seedlings contained approximately 22 % and 42 % of the applied algal N and P, respectively. Plants grown with algae-amended potting mixes were equivalent to plants grown with a liquid fertilizer with respect to dry weight and nutrient content.