Purvis, P., Chong, C. and Lumis, G. P. 2000. Recirculation of nutrients in container nursery production. Can. J. Plant Sci. 80: 39-45. This study evaluated (a) the capacity of a computerized injector to deliver and recirculate nutrients in a container nursery, and (b) plant growth and nutrient status under this regime compared with non-recirculated methods of fertilization, using Dart's Gold ninebark (Physocarpus opulifolius L. 'Dart's Gold') potted in 6-L containers filled with a medium of pine bark, peat, and soil (75, 15, and 10%, by volume). The injector was programmed to deliver NH 4 -N (24 mg L -1 ), NO 3 -N (196 mg L -1 ), P (54 mg L -1 ), and K (235 mg L -1 ) and other nutrients, with or without recirculation. Plants grown with recirculated nutrients were placed on aluminium troughs to collect the leachate, which was pumped back to the injector, recharged [based on a target electrical conductivity (EC) value of 1.85 dS m -1 ], and returned to the crop. Additional plants were grown on a crushed stone base and fertilized (a) by the computerized injector without recirculation, (b) with water soluble Plant-Prod 20-8-20 (200 mg L -1 N; non-recirculated) delivered through a Dosatron proportioner, or (c) with incorporated, controlled release Nutricote 18-6-8, Type 140 (6.5 kg m -3 ). NH 4 -N, NO 3 -N, P, and K concentrations delivered by the computerized injector (recirculated and non-recirculated; mean over six dates, 3 July to 28 August 1997) were 50, 22, 41, and 39%, respectively, lower than targeted values. Electrical conductivity values were not significantly different from targeted. The pH values (6.2 -6.4) were higher than targeted (6.0). The amounts of N, P, and K used were reduced by between 57 and 77% with recirculation compared to without. Notwithstanding reduced N, P, and K values, plants grew best with recirculated nutrients and least with non-recirculated liquid 20-8-20. 18-6-8, type 140 (6,5 kg M -3 ). Les concentrations de N ammoniacal et nitrique, de P et de K distribuées par l'injecteur (avec ou sans recyclage) étaient respectivement en moyenne (six dates échelon-nées du 3 juillet au 28 août 1997) de 50, 22, 41 et 39 % plus basses que les valeurs attendues. Les valeurs CE en revanche ne s'é-cartaient pas significativement des valeurs cibles mais les valeurs pH (6,2 à 6,4) étaient plus élevées que la valeur ciblée (6,0). Les quantités de N, P et K utilisées étaient diminuées de 57 à 77 % en circuit recyclé, mais malgré cela la meilleure croissance était obtenue avec les fertilisants recyclés. C'est la solution 20-8-20 sans recyclage qui produisait la croissance la moins bonne.

Rooted cuttings of `Antonovka' apple, `Lynwood Gold' forsythia, double-flowered kerria, common ninebark, `Goldfinger' potentilla, and `Red Prince' weigela were grown in 2-gal (6-L) nursery containers filled with 1:1 (by volume) of waste compost and composted pine bark, under three fertilizer regimes: 1) liquid nutrients [target concentrations in ppm (mg.L-1): NH4-N, 13; NO3-N, 100; P, 28; K, 120; Ca, 92; Mg, 13; Fe, 1.3; Mn, 0.27; Zn, 0.23; Cu, 0.05; B, 0.22; Mo, 0.05; Na, <50; Cl, <50; and SO4 <300] delivered and recycled twice per day via a computer-controlled multifertilizer injector; 2) same nutrient formula and concentration rate delivered fresh via the injector but without recycling; and 3) Nutryon (Polyon) 17-5-12 controlled-release fertilizer incorporated into the medium at a rate of 11 lb/yd3 (6.5 kg·m-3). With recycled liquid nutrients, all species grew the same or more than with nonrecycled nutrients, and generally the poorest growth was with controlled-release fertilizer. Foliar concentrations of K (all species), N (all species), P (forsythia, kerria, potentilla, and weigela), and Mn (forsythia, potentilla, and weigela) were higher in plants supplied with recycled and/or nonrecycled nutrients than in those supplied with controlled-release fertilizer, while foliar concentrations of Ca (ninebark and kerria) and Mg (apple, kerria, ninebark, potentilla, and weigela) were lower. Compared to nonrecycled liquid nutrients, the amounts of individual recycled nutrients were reduced by (percentage in brackets): NH4-N (30), NO3-N (78), P (76), K (46), Ca (93), Mg (96), Fe (52), Mn (43), Zn (55), Cu (60), B (83), and Mo (66).

No abstract

Chong, C. and Purvis, P. 2004. Nursery crop response to substrates amended with raw paper mill sludge, composted paper mill sludge and composted municipal waste. Can. J. Plant Sci. 84: 1127-1134. Silverleaf dogwood (Cornus alba L. 'Argenteo-marginata'), forsythia (Forsythia × intermedia Zab. 'Lynwood Gold'), and weigela (Weigela florida Bunge A.DC. 'Red Prince') were grown in #2 (6-L) containers filled with 100% bark or bark mixed with 20, 40 or 60% by volume each of raw paper mill sludge (RB group), Bio Soil compost containing 100% paper mill sludge (BCB group), Waterdown compost containing 40% paper sludge, 40% chicken manure and 20% sawdust (WCB group), and municipal compost consisting of leaf and yard waste (MCB group). A fifth substrate group (MCH) consisted of 100% hemp chips or hemp chips mixed with the same rates of municipal compost. The containers were trickle-irrigated and fertilized with a controlled-release fertilizer. Regression analysis indicated that growth among the barkamended groups was highest for dogwood and forsythia with WCB, increasing dramatically and peaking at about the 40% rate (68 and 94 g plant -1 aboveground dry weight, respectively). Growth of these species was intermediate with MCB and BCB and least with RB, increasing to rates ≥ 50% in these groups. There was no significant response of dogwood to RB. Growth of weigela increased equally with WCB and MCB substrates up to about 40% (117 g plant -1 ), but was not influenced by varying rates of RB and BCB. With the hemp-amended MCH group, growth of all three species increased to rates ≥ 50% (62, 93, and 116 g plant -1 for dogwood, forsythia and weigela, respectively). Growth of the three species over most rates of all substrate groups was similar to, or exceeded that in 80% bark: 15% peat: 5% topsoil, a proven nursery mix. Aboveground dry weight of all three species was positively correlated with soluble salts concentrations in the substrates sampled at planting and on other sampling dates during the season. . Ils ont aussi utilisé un cinquième substrat (MCH) entièrement constitué de copeaux de chanvre ou de copeaux de chanvre mélangés aux mêmes proportions de compost municipal. Les contenants ont été irrigués au goutte-à-goutte et fertilisés avec un engrais à libération lente. Parmi les substrats à base d'écorce, l'analyse de régression indique que le cornouiller et le forsythia connaissent la plus forte croissance avec le WCB, celle-ci se caractérisant par une hausse draconienne suivie d'un plateau au taux d'environ 40 % (68 et 94 g de poids sec des organes aériens par plant). Ces espèces connaissent une croissance moyenne avec les substrats MCB et BCB et la croissance la plus faible avec le substrat RB, jusqu'à un taux ≥ 50 %. Le cornouiller ne réagit pas de manière sensible au substrat RB. La croissance du weigela augmente de façon identique sur les substrats WCB et MCB jusqu'à environ 40 % (117 g par plant), mais elle ne varie pas avec la proportion de RB et de BCB. Avec le substrat MCH de copeaux de chanvre enrichis, les trois ...

Euonymus fortunei [(Turcz.) Hand.-Mazz.] ‘Emerald Gaiety’ and Thuja occidentalis L. ‘Little Giant’ were grown outdoors in #1 (3 liter) containers for one season on waterproof, crushed stone beds flooded and drained from below the stone. Plants were grown in a bark substrate (2/3 pine bark:1/3 sphagnum peat) or a peat substrate (1/3 pine bark:2/3 sphagnum peat) with either a high or medium rate of incorporated, controlled release fertilizer [17N–2.6P–10K (Sierra 17–6–12)] [6.0 or 4.0 kg/m3 (l0.0 or 6.7 lbs/yd3)]. For both species, the high fertilizer rate resulted in less top dry weight, and higher substrate electrical conductivity (EC) and NO3-N. Foliar N levels were also higher with the higher fertilizer rate. Compared with bark, the peat substrate resulted in less top dry weight of Thuja (not Euonymus) and higher substrate EC, NO3-N and water retention, and foliar N levels. Substrate EC levels in the upper one-third [5 cm (2 in)] of the container were nearly twice those in the lower two-thirds [10 cm (4 in)], reaching 7.1 dS/m with the high fertilizer rate in peat. In comparison to plants under overhead irrigation (high fertilizer rate only), flooded plants grew as much as (Euonymus) or more (Thuja) in the bark substrate but both species grew less in the peat. Substrate EC and NO3-N with flood were either similar or lower in bark, but similar or higher in peat compared to overhead. The amount of roots and their distribution appeared similar for both types of irrigation.