NITROGEN EXTRACTION FROM FOWL MANURES FOR FERTIGATION IN ORGANIC AGRICULTURE
Reuma Arusi1, Amit Gross1*, Pinchas Fine2, Zeev Ronen1and Ali Nejidat1
1 Department of Environmental Hydrology & Microbiology, Zuckerberg Institute for Water
Research, Israel
2 Institute of Soils, Water and the Environment, Israel
(free)
Supplementary N side dressing via the irrigation system is needed in organic cropping. The aims were to improve the N extraction efficiency that is usually about 10% by testing five extraction protocols differing in their mixing and aeration regimes with Guano, Layer and Broiler manures. The manure-N released in the different methods and manures was mainly ammonia and ranged from 50% to 85% with no differences among extraction methods. Volatilised ammonia from the extract solution was trapped and converted to nitrate. In the case of Guano, about 89% of the manure-N that was mineralised to the extract solution volatilised (after pH rise). In the Layer and Broiler manures only 23% and 34% were volatilised, respectively. Extraction of ammonia and its volatilisation can be significantly more efficient than using the extract solution as recommended today. It is possible to produce nitrate rich organic fertilizer by nitrification of volatilised ammonia from manure extracts.
KEY WORDS Ammonia volatilisation, Fertigation, Manure extraction, Nitrification, Nitrogen, Organic agriculture
