REDUCING PHOSPHORUS USE IN CRANBERRY PRODUCTION: HORTICULTURAL AND ENVIRONMENTAL IMPLICATIONS
Cranberry (Vaccinium macrocarpon) growers design fertility programs based on nitrogen requirements of the crop. For many years, use of easily available complete (nitrogen-phosphorus-potassium) fertilizers led to excessive phosphorus (P) applications. Based on more than 20 years of horticultural research, extension recommendations now state that P applications should not exceed 22 kg ha-1 per season. In the past 10 years, it has been suggested that, even when following this recommendation, P output from cranberry farms may exceed environmental mandates. To respond to this challenge, growers have been introduced to the use of low P fertilizers developed and tested by their peers. Within 3 years of intensive education, 65% of growers surveyed had reduced their P use but continued to question their ability to sustain production with reduced P. Growers were recruited to implement a P fertilizer program using 11 kg ha-1 or less and share the results with researchers and other growers. Their farms were studied from 2005 to 2011 to document production, tissue P levels, and improvement to environmental quality (change in P concentrations in surface water). At the site of the earliest adopter of the reduced P program, after 7 years of an average seasonal P application of 10 kg ha-1, crop yields were increased (compared to prior years), P concentration in harvest floods was reduced by >80%, and P concentration in winter floods was reduced by ~90%.
DeMoranville, C. 2014. REDUCING PHOSPHORUS USE IN CRANBERRY PRODUCTION: HORTICULTURAL AND ENVIRONMENTAL IMPLICATIONS. Acta Hort. (ISHS) 1017:447-453
Vaccinium macrocarpon, fertilizer, yield, water quality