scholarly journals Nutrient Release Characteristics From Four Types of Controlled-release Fertilizers

HortScience ◽  
2004 ◽  
Vol 39 (4) ◽  
pp. 797A-797
Author(s):  
Donald J. Merhaut* ◽  
Joseph Albano ◽  
Eugene K. Blythe ◽  
Julie Newman
Keyword(s):  
Controlled Release ◽  
Nutrient Release ◽  
Forest Products ◽  
Nutrient Content ◽  
Experimental Period ◽  
Release Rates ◽  
Calcium Magnesium ◽  
The Media ◽  
Iron Manganese ◽  
Controlled Release Fertilizers

Release patterns of ammonium, nitrate, phosphorus, potassium, calcium, magnesium, iron, manganese and zinc were measured during an eleven month period for four types of Controlled Release Fertilizers (CRF): Apex 17-5-11, Multicote 17-5-11, Nutricote 18-6-8 and Osmocote 24-4-9. Rate of fertilizer incorporation was 2.3 kg/m3 of nitrogen. Media consisted of 50% composted forest products, 35% ¼%-3/4% pine bark and 15% washed Builder's sand. The media was also amended with 0.60 kg/m3 of dolomite. Fertilizer was incorporated into the media with a cement mixer and placed into 2.6-L black polyethylene containers. Containers were placed on benches outside. Air and media temperature were monitored throughout the 11-month period. Containers were irrigated through a ring-dripper system. Leachate was collected twice weekly. Leachate electrical conductivity, pH, and nutrient content were measured weekly. Significant differences in the nutrient release patterns were observed between fertilizer types throughout much of the experimental period. Release rates were significantly greater during the first 20 weeks of the study compared to the last 20 weeks of the study, regardless of the fertilizer type.

scholarly journals Nutrient Release from Controlled-release Fertilizers in Acid Substrate in a Greenhouse Environment: II. Leachate Calcium, Magnesium, Iron, Manganese, Zinc, Copper, and Molybdenum Concentrations

HortScience ◽  
2006 ◽  
Vol 41 (3) ◽  
pp. 788-793 ◽  
Author(s):  
Eugene K. Blythe ◽  
Donald J. Merhaut ◽  
Julie P. Newman ◽  
Joseph P. Albano
Keyword(s):  
Controlled Release ◽  
Cultural Practices ◽  
Nutrient Release ◽  
Greenhouse Production ◽  
Production Program ◽  
Manganese Zinc ◽  
Calcium Magnesium ◽  
Iron Manganese ◽  
Acid Substrate ◽  
Controlled Release Fertilizers

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.

scholarly journals Plant Growth and Leachate Electrical Conductivity and pH as Influenced by Controlled-release Fertilizer Blends and Coating Technologies

2017 ◽  
Vol 27 (5) ◽  
pp. 639-643 ◽  
Author(s):  
Carey Grable ◽  
Joshua Knight ◽  
Dewayne L. Ingram
Keyword(s):  
Trace Elements ◽  
Controlled Release ◽  
Polymer Coating ◽  
Ornamental Plants ◽  
Nutrient Release ◽  
Dry Weight ◽  
Polymer Coatings ◽  
Release Rates ◽  
Shoot Dry Weight ◽  
Controlled Release Fertilizers

Although controlled-release fertilizers (CRFs) have been used in container-grown ornamental plants for decades, new coating technologies and blends of fertilizers coated for specific release rates are being employed to customize fertility for specific environments and crops. A study was conducted in the transitional climate of Kentucky to determine the nutrient release rates of three controlled-release blends of 8- to 9-month release and growth response of ‘Double Play Pink’ japanese spirea (Spiraea japonica) and ‘Smaragd’ arbovitae (Thuja occidentalis). Fertilizer 1 (16N–3.5P–8.3K–1.8Mg + trace elements) and Fertilizer 2 (18N–3.1P–8.3K–1.8Mg + trace elements) were prototype blends with different experimental polymer coatings. Fertilizer 3 was a blend of 18N–2.2P–6.6K–1.1Ca–1.4Mg–5.8S + trace elements, which combined 100% resin-coated prills with a polymer coating. Fertilizer 4 was commercially available 15N–3.9P–10K–1.3Mg–6S + trace elements. Fertilizer 3 released its nutrients earlier in the 12-week study than the other three fertilizers and resulted in lower shoot dry weight in both species. The new polymer coating technologies show promise for delivering a predicted release rate and are appropriate for container production of these woody shrubs in Kentucky. An interesting side note of this experiment was that leachate pH measurements across treatments averaged 1.2 units lower for arbovitae (6.3) than for japanese spirea (7.5) at week 12. It was assumed that chemical and/or biological reactions at the root/substrate interface in arbovitae moderated pH increases over the study.

Determination of Nitrogen, Phosphorus, and Potassium Release Rates of Slow- and Controlled-Release Fertilizers: Single-Laboratory Validation, First Action 2015.15

2016 ◽  
Vol 99 (2) ◽  
pp. 353-359 ◽  
Author(s):  
Nancy Thiex
Keyword(s):  
Controlled Release ◽  
Nutrient Release ◽  
Official Method ◽  
Release Rates ◽  
Expert Review ◽  
Expert Review Panel ◽  
Phosphorus And Potassium ◽  
Single Laboratory ◽  
Controlled Release Fertilizers

Abstract A previously validated method for the determination of nitrogen release patterns of slow- and controlled-release fertilizers (SRFs and CRFs, respectively) was submitted to the Expert Review Panel (ERP) for Fertilizers for consideration of First Action Official MethodSM status. The ERP evaluated the single-laboratory validation results and recommended the method for First Action Official Method status and provided recommendations for achieving Final Action. The 180 day soil incubation-column leaching technique was demonstrated to be a robust and reliable method for characterizing N release patterns from SRFs and CRFs. The method was reproducible, and the results were only slightly affected by variations in environmental factors such as microbial activity, soil moisture, temperature, and texture. The release of P and K were also studied, but at fewer replications than for N. Optimization experiments on the accelerated 74 h extraction method indicated that temperature was the only factor found to substantially influence nutrient-release rates from the materials studied, and an optimized extraction profile was established as follows: 2 h at 25°C, 2 h at 50°C, 20 h at 55°C, and 50 h at 60°C.

Evaluation of a Soil Incubation Method to Characterize Nitrogen Release Patterns of Slow- and Controlled-Release Fertilizers

2014 ◽  
Vol 97 (3) ◽  
pp. 643-660 ◽  
Author(s):  
L Carolina Medina ◽  
Jerry B Sartain ◽  
Thomas A Obreza ◽  
William L Hall ◽  
Nancy J Thiex
Keyword(s):  
Controlled Release ◽  
Release Rate ◽  
Nutrient Release ◽  
Soil Incubation ◽  
Release Rates ◽  
N Release ◽  
Production And Distribution ◽  
Slow Release Fertilizers ◽  
Incubation Temperatures ◽  
Controlled Release Fertilizers

Abstract Several technologies have been proposed to characterize the nutrient release patterns of slow- release fertilizers (SRF) and controlled-release fertilizers (CRF) during the last few decades. These technologies have been developed mainly by manufacturers, and are product-specific, based on the regulation and analysis of each SRF and CRF product. Despite previous efforts to characterize SRF and CRF materials, no standardized, validated method exists to assess their nutrient release patterns. However, the increased production and distribution of these materials in specialty and nonspecialty markets requires an appropriate method to verify product claims and material performance. A soil incubation column leaching procedure was evaluated to determine its suitability as a standard method to estimate nitrogen (N) release patterns of SRFs and CRFs during 180 days. The influence of three soil/sand ratios, three incubation temperatures, and four soils on method behavior was assessed using five SRFs and three CRFs. In general, the highest soil/sand ratio increased the N release rate of all materials, but this effect was more marked for the SRFs. Temperature had the greatest influence on N release rates. For CRFs, the initial N release rates and the percentage N released/day increased as temperature increased. For SRFs, raising the temperature from 25 to 35°C increased initial N release rate and the total cumulative N released, and almost doubled the percentage released/day. The percentage N released/day from all products generally increased as the texture of the soil changed from sandy to loamy (Iowa>California>Pennsylvania>Florida). The soil incubation technique was demonstrated to be robust and reliable for characterizing N release patterns from SRFs and CRFs. The method was reproducible, and variations in soil/sand ratio, temperature, and soil had little effect on the results.

Nutrient‐Release Rates of Controlled‐Release Fertilizers in Forest Soil

2007 ◽  
Vol 38 (5-6) ◽  
pp. 739-750 ◽  
Author(s):  
Diane L. Haase ◽  
Patricio Alzugaray ◽  
Robin Rose ◽  
Douglass F. Jacobs
Keyword(s):  
Controlled Release ◽  
Forest Soil ◽  
Nutrient Release ◽  
Release Rates ◽  
Controlled Release Fertilizers

scholarly journals Leachate Nutrient Content and Growth of Two Hollies As Influenced by Controlled Release Fertilizers

1992 ◽  
Vol 10 (3) ◽  
pp. 162-166
Author(s):  
John M. Ruter
Keyword(s):  
Electrical Conductivity ◽  
Controlled Release ◽  
Growth Response ◽  
Nutrient Content ◽  
Good Growth ◽  
Linear Relationships ◽  
Ilex Cornuta ◽  
Source Rate ◽  
Liquid Fertilization ◽  
Controlled Release Fertilizers

Abstract An experiment was conducted to evaluate the effects of fertilizer source, rate of application, and method of application on the release of nutrients over time using the pour-through method and to determine the growth response of Ilex cornuta Lindl. & Paxt. ‘Burfordii’ and Ilex × ‘Nellie R. Stevens’ holly to different multicoated controlled release fertilizers (CRF). Depending on the rate of application used, the three CRFs used in this study [Osmocote 17N-3P-9.9K (17-7-12), Sierrablen 17N-3P-8.3K (17-7-10), and High-N 24N-1.7P-5.8K (24-4-7)] provided adequate concentrations of nutrients for a minimum of 90 days after treatment. Fertilizer source had no effect on the growth of either holly used in this study. Good growth of ‘Burfordii’ and ‘Nellie R. Stevens’ holly was obtained at the rate of 1. 5 kg N/m3 (2. 5 lb N/yd3). Linear relationships between NO3-N and electrical conductivity using the pour-through method were established for ‘Burfordii’((NO3-N = 414 (electrical conductivity)) and ‘Nellie R. Stevens’ ((NO3−N =−11.4 + 425 (electrical conductivity)). Results of this study indicate that the nutrient sufficiency values for liquid fertilization programs with the pour-through method need to be adjusted for use with multicoated CRFs.

scholarly journals Nitrogen Release Properties of Controlled-release Fertilizers during Tomato Production

HortScience ◽  
2014 ◽  
Vol 49 (12) ◽  
pp. 1568-1574 ◽  
Author(s):  
Luther C. Carson ◽  
Monica Ozores-Hampton ◽  
Kelly T. Morgan ◽  
Jerry B. Sartain
Keyword(s):  
Controlled Release ◽  
Nonlinear Regression ◽  
Nutrient Release ◽  
Nitrogen Release ◽  
Data Logger ◽  
Tomato Crop ◽  
Tomato Production ◽  
N Release ◽  
Soil Temperatures ◽  
Controlled Release Fertilizers

Determination of nutrient release duration from controlled-release fertilizers (CRFs) or soluble fertilizers encapsulated in polymer, resin, or sulfur covered fertilizer coated with a polymer differs among manufacturers, but may be determined as 75% to 80% nitrogen (N) release at a constant temperature (e.g., 20 to 25 °C). Increases or decreases in temperature compared with the manufacturer release determination temperature increase or decrease CRF N release; thus, coated fertilizer may release more rapidly than stated during the fall season when soil temperatures in seepage-irrigated tomato (Solanum lycopersicum) production can reach 40.1 °C. The objectives of this study were to evaluate N release duration of CRFs by measuring N release from CRFs incubated in pouches under polyethylene mulch-covered raised beds and to determine the CRF duration suitable for incorporation into a fall tomato fertility program. In 2011 and 2013, 12 and 14 CRFs from Agrium Advanced Technologies, Everris, Florikan, and Chisso-Asahi Fertilizer were sealed in fiberglass mesh pouches (12.7 × 14 cm) that were buried 10 cm below the bed surface in a tomato crop grown using commercial production practices. A data logger collected soil temperature 10 cm below the bed surface. Pouches were collected and N content was measured eight times through two fall seasons. A nonlinear regression model was fit to the data to determine N release rate. During the 2011 and 2013 seasons, minimum, average, and maximum soil temperatures were 21.2 and 19.2, 25.7 and 23.5, and 32.2 and 27.7 °C, respectively. Seasonal total CRF N release was between 77.6% and 93.8% during 2011 and 58.3% and 94.3% in 2013. In 2011, PCU90 and in 2013, PCU90 and PCNPK120 had the highest seasonal total percentage N release (PNR) and FL180 had the lowest in both years. A nonlinear regression fit N release from CRF with R2 = 0.85 to 0.99 during 2011 and 0.49 to 0.99 during 2013. Nitrogen release from all CRFs was faster than the manufacturer’s stated release, probably as a result of high fall bed temperatures. A CRF or CRF mixture containing CRFs of 120- to 180-day release duration may be recommended, but the CRFs must release greater than 75% N during the season.

scholarly journals 372 Nitrogen and Phosphorus Release from Controlled-release Fertilizers while Overwintering Nursery Stock under Plastic

HortScience ◽  
2000 ◽  
Vol 35 (3) ◽  
pp. 456D-456
Author(s):  
Andrew Ristvey ◽  
John Lea-Cox
Keyword(s):  
Controlled Release ◽  
Variable Temperature ◽  
Nutrient Release ◽  
Phosphorus Release ◽  
Early Spring ◽  
Late Winter ◽  
Nitrogen And Phosphorus ◽  
Major Loss ◽  
Few Data ◽  
Controlled Release Fertilizers

Nutrient release patterns from several different controlled-release fertilizers (CRF) were studied during the overwintering period of a long-term nutrient uptake, leaching, and loss study of Azalea (Rhododendron) cv. `Karen' and Holly (Ilex cornuta) cv. `China Girl', under sprinkler and drip irrigation. In Maryland, diurnal winter temperatures can vary from ≈10 °C to above 15 °C. Most growers, therefore, cover frames with opaque plastic for cold protection from November through April. This is also the period when many growers apply CRFs on those plant species that take more than 1 year to produce. Few data are presently available on the release patterns of CRFs under variable temperature conditions in late winter/early spring. We hypothesized that substrate temperatures warmer than 15–16 °C will result in CRFs releasing nutrients at a time when root systems are inactive, with a major loss of nutrients with the first few irrigations in Spring. This 105-day study quantified nitrogen (N) and phosphorus release patterns from four brands of CRF (Osmocote, Nutricote, Scotts High N, and Polyon) with 270- and 360-day release rates, under these conditions. Each CRF was top dressed onto blocks of 18-month-old holly or azalea (n = 112) in 11.5-L (3-gal) containers, at a (low) rate of 6.1 g N per container. Ten randomly selected pots from each treatment were sampled every 15 days using two sequential leachings of distilled water, for a target leaching fraction of 25%. Leachates were recovered and analyzed for nitrate and orthophosphate concentrations. Ambient canopy temperatures were recorded continuously with remote temperature (HoBo) sensors from which degree days above 15–16 °C were calculated and correlated with CRF release patterns.

scholarly journals Comparative Evaluation of Nitrogen Release Patterns from Controlled-release Fertilizers by Nitrogen Leaching Analysis

HortScience ◽  
1997 ◽  
Vol 32 (4) ◽  
pp. 669-673 ◽  
Author(s):  
Raul I. Cabrera
Keyword(s):  
Controlled Release ◽  
Experimental Period ◽  
N Leaching ◽  
N Losses ◽  
Ambient Temperatures ◽  
Average Maximum ◽  
N Release ◽  
Fast Start ◽  
Controlled Release Fertilizers ◽  
Leaching Pattern

Seven nursery grade (8-9 month duration), polymer-coated, controlled-release fertilizers (CRF) were topdressed or incorporated into a 2 peat: 1 vermiculite: 1 sand (by volume) medium to yield the same amount of N per container. The pots (0.5 L) were uniformly irrigated with DI water every week to produce a target leaching fraction of 25%. Leachate N contents (ammonium plus nitrate), employed as indicators of N release, allowed for comparison of CRF performance as a function of temperature changes over a season. Two distinct N leaching (i.e., release) patterns were observed over the 180-day experimental period. The fertilizers Osmocote 18-6-12FS (Fast Start: OSM-FS), Prokote Plus 20-3-10 (PROK), Osmocote 24-4-8HN (High N: OSM-HN) and Polyon 25-4-12 (POLY) exhibited a N leaching pattern that closely followed changes in average daily ambient temperatures (Tavg) over the season. This relationship was curvilinear, with N leaching rates per pot (NLR) being highly responsive to Tavg changes between 20 and 25 °C. Temperatures above 25 °C produced an average maximum NLR of 1.27 mg·d-1 for these fertilizers. OSM-FS, PROK, and OSM-HN had the highest cumulative N losses over the experimental period. In contrast, the CRF group formed by Nutricote 18-6-8 (270: NUTR), Woodace 20-4-12 (WDC), and Osmocote 18-6-12 (OSM) showed a more stable N leaching pattern over a wider range of temperatures, with rates about 30% to 40% lower than those in the temperature-responsive CRF, and averaging a maximum NLR of 0.79 mg·d-1 for Tavg >25 °C. NUTR and WDC had the lowest cumulative N losses over the season. Soluble salt readings paralleled N leaching for each CRF, indicating similar leaching patterns for other nutrients. Incorporation produced significantly higher cumulative N losses than topdressing, but without effect on the actual N leaching pattern over the season. Regardless of the N formulation in the CRF, over 85% of the N recovered in the leachates was in the nitrate form.

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