Nutrient release from Nutricote Type 100 (100-day N release; 16N-4.4P-8.1K), and from a 1:3 mixture of Nutricote Type 40 (40-day N release; 16N-4.4P-8.1K) and Type 100 was affected by time and temperature. The Type 40/100 mixture released nutrients more rapidly over a 5 to 35C range in laboratory studies. Seasonal growth of containerized cotoneaster (Cotoneaster dammeri C.K. Schneid `Coral Beauty') and juniper (Juniperus horizontalis Moench. `Plumosa Compacta') increased with increasing application rates of either Nutricote Type 100 or a 1:3 mixture of Type 40/100 over the range 2-10 kg·m-3. Between 25 June and 27 July, cotoneaster grew more rapidly in media with Type 40/100 Nutricote, but by the end of the season (27 Sept.), fertilizer type showed no effect on plant dry weight. Shoot N was higher in cotoneaster plants grown with Type 40/100 Nutricote than with the Type 100 formulation during the first 2 months of growth, reflecting the more rapid release and uptake of N from the mixture. During the last month the situation was reversed, as nutrients from the Type 40/100 mixture were depleted. Potassium and P shoot concentrations were not affected by fertilizer type. Juniper growth and shoot concentrations of N, K, and P were not affected by fertilizer type at any time during the season. The results provided no evidence that seasonal growth could be enhanced in either cotoneaster (grows rapidly) or juniper (slower growing) by mixing rapid and more slowly releasing types of Nutricote.
Peter R. Hicklenton and Kenneth G. Cairns
Joseph P. Albano, Donald J. Merhaut, Eugene K. Blythe, and Julie P. Newman
Nutrient release characteristics of four different controlled-release fertilizers (Osmocote, Nutricote, Polyon, and Multicote) were monitored during an 11-month period in a simulated outdoor nursery production facility. Although no plants were used in the experiment, fertilization rates, irrigation regimes, and cultural practices simulated those typically used to produce fast-growing, high-nutrient-requiring containerized woody ornamentals. Fertilizer prill release characteristics were monitored through analyses of leachates, which were collected weekly. Concentrations of Mg, Mn, Zn, Cu, and Mo were relatively high during the first 5 to 10 weeks of the experiment, then declined and usually stabilized during the remainder of the study. However, Mn and Zn displayed erratic increases in concentrations several times throughout the study. Calcium concentrations did not increase until the fifth week, rapidly peaked to about 300 mg·L–1, and then decreased and leveled off to ≈80 to 100 mg·L–1 during the remainder of the study. Several significant differences were observed between treatments. The Osmocote treatment had significantly greater Ca and Mg concentrations in the leachate than the other fertilizer types during the last 6 weeks of the study, whereas the Nutricote treatment often had significantly greater Fe concentrations than leachates from other treatments, especially during the last 26 to 35 weeks of the study, and significantly greater Zn concentrations than the other CRFs during the last 21 weeks of the study. Based upon U.S. Environmental Protection Agency guidelines, concentrations of Fe were often more than the allowable limit of 0.3 mg·L–1 with all fertilizer types, but especially with Nutricote. Concentrations of Mn and Cu also exceeded federal guidelines, particularly during the first several weeks of the study.
Eugene K. Blythe, Donald J. Merhaut, Julie P. Newman, and Joseph P. Albano
Leachate from containerized substrate containing one of four different controlled-release fertilizers (Osmocote, Nutricote, Polyon, or Multicote) were monitored for concentrations of Ca, Mg, Fe, Mn, Zn, Cu, and Mo during a 47-week period. Environmental and cultural practices simulated an unheated greenhouse production program typically used for low-nutrient-requiring crops such as azalea and camellia. Leachate concentrations of all nutrients were relatively high during the first 10 to 20 weeks of the study, and then gradually decreased during the remaining portion of the experiment. Few differences were observed among fertilizer types. Of the elements monitored, only Fe and Mn leachate concentrations were above critical levels specified in the Clean Water Act by the U.S. EPA.
Julie P. Newman, Joseph P. Albano, Donald J. Merhaut, and Eugene K. Blythe
Release characteristics of four different polymer-coated fertilizers (Multicote, Nutricote, Osmocote, and Polyon) were studied over a 47-week period in a simulated outdoor, containerized plant production system. The 2.4-L containers, filled with high-fertility, neutral-pH substrate, were placed on benches outdoors to simulate the environmental conditions often used for sun-tolerant, woody perennials grown in the southwestern United States. Container leachates were collected weekly and monitored for electrical conductivity, pH, and concentrations of NH4 +N, NO3 –N, total P, and total K. Concentrations of most nutrients in leachates were relatively high, but fluctuated frequently during the first third of the study period, and then gradually decreased and stabilized during the last 27 weeks. Osmocote often resulted in greater NH4 + and total inorganic N concentrations in leachates than other fertilizers during weeks 1 through 5, whereas Multicote produced higher NH4 + in leachates than most of the other fertilizer types during weeks 9 through 12. Overall, total P concentrations were greater with Multicote during a third of the experimental period, especially when compared with Osmocote and Polyon. Differences were also observed among treatments for leachate concentrations of K, with Polyon and Multicote fertilizers producing greater K concentrations in leachates compared with Osmocote during several weeks throughout the experimental period. Leachate concentrations of NO3 –N and P from all fertilizer types were usually high, especially from week 5 through week 30.
Donald J. Merhaut, Eugene K. Blythe, Julie P. Newman, and Joseph P. Albano
Release characteristics of four types of controlled-release fertilizers (Osmocote, Nutricote, Polyon, and Multicote) were studied during a 47-week simulated plant production cycle. The 2.4-L containers containing a low-fertility, acid-based substrate were placed in an unheated greenhouse and subjected to environmental conditions often used for production of azaleas and camellias. Leachate from containers was collected weekly and monitored for pH, electrical conductivity, and concentrations of NH4 + N, NO3 –N, total P and total K. Leachate concentrations of all nutrients were relatively high during the first 10 to 20 weeks of the study, and then gradually decreased during the remaining portion of the experiment. Differences were observed among fertilizer types, with Multicote often resulting in higher concentrations of N, P, and K in leachates compared to the leachates from the other fertilizer types during the first half of the study. Concentrations of NO3 – and P from all fertilizer types were often above permissible levels as cited in the federal Clean Water Act.
Kaitlyn McBride, Richard J. Henny, Jianjun Chen, and Terri A. Mellich
potting, all plants were trimmed to 5.0 to 7.5 cm in height and Nutricote ® Plus (18N–2.6P–6.6K; 140-d formulation) controlled-release fertilizer (Chisso-Asahi Fertilizer Co., Ltd., Tokyo, Japan) was applied to the substrate surface at 2.5, 5.0, or 7.5 g
Jeff Million, Tom Yeager, and Claudia Larsen
before filling with substrate. The top of the wick was 3 cm below the substrate surface and the tail extended 15 cm from the bottom of the container. A resin-coated CRF (Nutricote 17N–3.1P–6.7K, 180 d at 77 °F; Florikan, Sarasota, Fla.) was incorporated
Mohammed Z. Alam, Calvin Chong, Jennifer Llewellyn, and Glen P. Lumis
cm diam. × 21 cm deep) nursery containers filled with a medium consisting of 65% by volume of pine bark:25% peatmoss: 10% compost [Grow-Bark (Ontario) Ltd., Milton, Ontario, Canada]. Nutricote 18-6-8 (18N–6P–8K) T100 CRF with micronutrients (Plants
Tom Yeager and Geri Cashion
Container plant runoff NO3-N levels varied with sampling time and were periodically higher than the 10-ppm federal drinking water standard during 4.5 months following fertilizer application, even though controlled-release fertilizers Nutricote 18N-2.6P-6.6K Osmocote 18N-2.6P-10K, Prokote 20N-1.3P-8.3K, and Woodace 19N-2.6P-10K were used. Leachate collected from containers had a higher NO3-N level than runoff regardless of sampling time. Leachate NO3-N ranged from 278 ppm for Nutricote 3.5 months after application to 6 ppm for Prokote 1 week after application.
Plugs of Leucanthemum × superbum `Becky' (Chrysanthemum `Becky', shasta daisy) were grown in #2 containers using pine bark–peat–sand or vermiculite–peat–sand (40:40:20 by volume). Containers were top dressed with either Osmocote Plus 15N–3.9P–9.9K (15–9–12) or Nutricote Plus (18N–2.6P–6.6K (18–6–8) at five rates (0, 0.5×, 1.0×, 1.5×, and 2.0×) to supply 3.9 g N per container at the recommended level (1.0×). Plants were irrigated twice a week using a cyclic irrigation regime consisting of two irrigation applications. Leachates from these containers were collected and evaluated for nitrate and orthophosphate concentrations. Irrespective of the substrate media, Osmocote Plus exhibited a higher rate of nitrogen release at the beginning of the season than Nutricote Plus. Nitrate nitrogen concentration was at least 2.5 times higher in leachates collected from media amended with Osmocote Plus than those with Nutricote Plus. Higher levels of nitrate were found in leachates collected from vermiculite-based media when compared to those from bark-based ones. Phosphate levels in leachates increased as rate of fertilizer increased and were higher in vermiculite-based media than those collected from bark-based media. Plants fertilized with Osmocote Plus were 1.7-fold greater in dry weight than plants fertilized with Nutricote Plus and were 1.2 times greater in vermiculite-based media than those in bark-based media.