Nitrogen and Phosphorus Dynamics in the Shallow Lake Agmon (Hula Valley, Israel)

Abstract

Lake Agmon is a newly created shallow body of water which is a principle component of a reclamation project (Hula Project, HP) in the Hula Valley (Israel). The objectives of the HP are aimed at Lake Kinneret water quality protection, and improvements of the hydrological, and agricultural managements within the entire Hula Valley including the eco-touristic quality of the Agmon site. Thirteen years of research and monitoring, are summarized by focusing on nitrogen and phosphorus dynamics. It was found that the decay of submerged vegetation was the major P contribution to the Agmon effluents as dissolved (TDP) and plant debris particle forms. Peat soil gypsum dissolution contribute sulfate to drained waters and consequently to Agmon outflows. The Agmon system is operated as a nitrogen sink by de-nitrification and particulate sedimentation and contributor of plant mediated phosphorus. In the reconstructed Jordan flows into the Agmon, a stable composition of nutrients was indicated but those of the peat drainage and the lake effluents represented the higher level in winter and lower in summer. Anoxic conditions in the water column enhancing sulfate reduction are negligible and rarely observed. The Agmon merit to the reclamation process was achieved.