Nitrogen budgeting for water quality improvement in pineapple production systems of south eastern Queensland, Australia.

The Glass House Mountains area was identified as a source of elevated nitrogen (N) which flows into the Pumicestone Passage and Moreton Bay. Elevated N causes decline in water quality and ecological function of these internationally important Ramsar wetlands, fisheries habitat, and recreational tourism natural amenities. Investigations into the origin of elevated aquatic N levels identified intensive horticultural activities were likely key contributors. A review of horticulture in the catchment was undertaken. The review determined that pineapple production systems in this area presented the largest opportunity for addressing aquatic N levels. Using a systems agronomy approach a partial N budget and review of nutrient management practices investigated nitrogen use efficiency (NUE). Findings identified N loading in waterways was impact by rainfall volume and frequency. Agronomic timing of N application to meet plant demand was imbalanced. Deep drainage is the predominant N loss pathway in major soil types of the catchment