Wastewaters from farm and composting operations are often rich in select nutrients that potentially can be reutilized in crop production.
Liners of silverleaf dogwood (Cornus alba L. ‘Argenteo-marginata’), common ninebark [Physocarpus opulifolius (L.) Maxim.], and
Anthony Waterer spirea (Spiraea · bumalda Burve´nich ‘Anthony Waterer’) were grown in 6 L containers filled with a bark-based commercial
mix. Plants were fertigated daily via a computer-controlled multi-fertilizer injector with three recirculated fertilizer treatments: (1)
a stock (control) solution with complete macro- and micro-nutrients, electrical conductivity (EC) 2.2 dS m1
; (2) wastewater from a
mushroom farm; and (3) process wastewater from anaerobic digestion of municipal solid waste. The wastewaters used in both treatments
2 and 3 were diluted with tap water, and the computer was programmed to amend, dispense and recirculate nutrients based on the same
target EC as in treatment 1. For comparison, there was a traditional controlled-release fertilizer treatment [Nutryon 17-5-12 (17N–2P–
10K) plus micro-nutrients topdressed at a rate of 39 g/plant, nutrients not recirculated]. All three species responded similarly to the three
recirculated fertilizer treatments. Growth with the recirculated treatments was similar and significantly higher than that obtained with
controlled-release fertilizer. Throughout the study, the EC measured in wastewater-derived nutrient solutions, and also in the container
substrate, were similar or close to those of the control treatment, although there were small to large differences among individual major
nutrients. There was no sign of nutrient deficiency or toxicity symptoms to the plants. Small to moderate excesses in concentrations of
SO4, Na, and/or Cl were physiologically tolerable to the species.
2007 Elsevier Ltd. All rights reserved.
Keywords: Nutrient recirculation; Wastewater recycling; Fertigation; Container culture; Ornamentals; Woody species