Phosphorus Rate, Leaching Fraction, and Substrate Influence on Influent Quantity, Effluent Nutrient Content, and Response of a Containerized Woody Ornamental Crop

Abstract

<jats:p>Production of containerized nursery crops requires high inputs of water and mineral nutrients to maximize plant growth to produce a salable plant quickly. However, input efficiencies remain below 50% resulting in major quantities of water and nutrients leached. This study was conducted to determine if production factors could be altered to increase water and phosphorus uptake efficiency (PUE) without sacrificing plant growth. The effects of a pine bark substrate amendment (clay or sand) and a 50% reduction in both P application rate (1.0 g or 0.5 g) and leaching fraction (LF = effluent ÷ influent) (0.1 or 0.2) were investigated. Containerized Skogholm cotoneaster (<jats:italic>Cotoneaster dammeri</jats:italic> Schnied. ‘Skogholm’) was grown on gravel floor effluent collection plots that allowed for calculation of water and nutrient budgets. Pine bark amended with 11% (by vol.) Georgiana 0.25 to 0.85 mm calcined palygorksite-bentonite mineral aggregate (clay) increased available water 4% when compared with pine bark amended with 11% (by volume) coarse sand. Decreasing LF from 0.2 to 0.1 reduced cumulative container influent 25% and effluent volume 64%, whereas total plant dry weight was unaffected by LF. Reduction of target LF from 0.2 to 0.1 reduced dissolved reactive P concentration and content by 8% and 64%, respectively. In a sand-amended substrate, total plant dry weight decreased 16% when 1.0× P rate was reduced to 0.5× P, whereas total plant dry weight was unaffected by rate of P when pine bark was amended with clay. Plant content of all macronutrients, with the exception of N, increased when pine bark was amended with clay versus sand. Reducing P rate from 1.0× to 0.5× increased PUE 54% or 11% in a clay or sand-amended substrate, respectively. Amending pine bark with 11% (by volume) 0.25 to 0.85 mm calcined palygorksite-bentonite mineral aggregate produced an equivalent plant with half the P inputs and a 0.1 LF, which reduced water use 25% and P effluent losses 42% when compared with an industry representative substrate [8 pine bark : 1 sand (11% by volume)].</jats:p>

Replacing Conventional Nursery Crop Nutrient Inputs with Vermicompost for Container Production of Hibiscus moscheutos L. ‘Luna Blush’

“…For 20VC + NPK, 20VC + NK, 20VC + N, and PBS + NPK, the NUE N was 12%, 11%, 15%, and 9% and NUE P was 8%, 11%, 12%, and 7%, respectively (Tables 4 and 5). These nutrient use efficiency values are at the lower end of the ranges reported by others (Owen et al, 2008;Ristvey et al, 2007;Stoven et al, 2006). For azalea (Rhododendron var.…”

“…These higher nutrient use efficiencies were associated with lower respective N and P fertilization rates. Owen et al (2008) also reported an increased NUE P from 21% to 34% when cotoneaster (Cotoneaster dammeri Schnied. 'Skogholm') grown in a pine bark sand substrate received P at a full rate and half rate, respectively.…”

“…'Prairifire' (Prairifire crabapple), Cercis canadensis L. (Eastern redbud), and Acer ·freemai 'Jeffersred' (Autumn Blaze Ò maple), respectively, when grown outdoors and fertilized with CRF. Reduction of LF is another approach to improve nutrient use efficiency (Fare et al, 1994;McGinnis, 2007;Owen et al, 2008;Tyler et al, 1996). Leaching fraction reduction results in decreased nutrient effluent volume and content.…”

Response of Container-grown Confetti Tree Irrigated with Runoff Water

“…Among these Mediterranean species, kneeholy and confetti tree are widely grown for their commercial value (Lopez, 2004;Veronese, 2014). Although there are a number of publications that have investigated the reuse of runoff water in nursery production (Owen et al, 2008;Polomski et al, 2005Polomski et al, , 2008, little is known about reusing irrigation water for the production of confetti tree. A greenhouse experiment was conducted to determine the effects of different irrigation treatments on biomass, mineral composition, and photosynthetic parameters of this species.…”

Water Use and Growth of Hibiscus acetosella ‘Panama Red’ Grown with a Soil Moisture Sensor-controlled Irrigation System

“…Research has related plant water use to plant growth index and pan evaporation (Knox, 1989) or growth index and leaf area (Nui et al, 2006), which were shown to be good descriptors of water use for multiple species. Maintenance of specific leaching fractions has also been used to adjust irrigation in response to increasing plant size (Owen et al, 2008). However, these methods do not adjust to day-to-day changes in weather.…”