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.

scholarly journals Growth of Bedding Plants in Substrates Amended with Compost and Fertilized with Three Different Release Rates of a Controlled-release Fertilizer Product

2004 ◽  
Vol 14 (4) ◽  
pp. 474-478 ◽  
Author(s):  
Kimberly K. Moore
Keyword(s):  
Controlled Release ◽  
Dry Weight ◽  
Application Rate ◽  
Release Rates ◽  
Controlled Release Fertilizer ◽  
Bedding Plants ◽  
Shoot Dry Weight ◽  
Standard Application ◽  
Impatiens Wallerana

Growth of `Aladdin Peach Morn' petunia (Petunia × hybrida) and `Accent White' impatiens (Impatiens wallerana) was compared in substrates containing 0%, 30%, 60%, or 100% compost made from biosolids and yard trimmings and fertilized with Nutricote Total 13-13-13 (13N-5.7P-10.8K) Types 70, 100, and 140 incorporated at rates of 0.5x, 1x, 2x, or 3x (x = standard application rate for a medium-feeding crop). Petunia shoot dry weight of plants fertilized with Type 70 incorporated at 0.5x increased as the percentage of compost in the substrate increased from 0% to 60% and then decreased, while shoot dry weight of plants fertilized with Type 70 incorporated at 1x, 2x, or 3x increased as the percentage of compost increased from 0% to 30% and then decreased. Impatiens shoot dry weight of plants fertilized with Type 70 incorporated at 0.5x and 1x also increased as the percentage of compost increased from 0% to 30% and then decreased, while shoot dry weight of plants fertilized at 2x and 3x decreased as the percentage of compost increased from 0% to 100%. Both petunia and impatiens shoot dry weight of plants fertilized with Type 100 and Type 140 incorporated at 0.5x, 1x, 2x, or 3x increased as the percentage of compost increased from 0% to 60% and then decreased.

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.

A comprehensive review on biodegradable polymers and their blends used in controlled-release fertilizer processes

2015 ◽  
Vol 31 (1) ◽  
Author(s):  
Zahid Majeed ◽  
Nur Kamila Ramli ◽  
Nurlidia Mansor ◽  
Zakaria Man
Keyword(s):  
Controlled Release ◽  
Biodegradable Polymers ◽  
Crop Yields ◽  
Nutrient Release ◽  
Polymer Coatings ◽  
Classification Criteria ◽  
Methodological Issues ◽  
Comprehensive Review ◽  
Modeling Data ◽  
Controlled Release Fertilizers

AbstractBiodegradable polymer-coated controlled-release fertilizers (PC-CRFs) are essential means to reduce cost, improve marketability, conserve land fertility, achieve high crop yields and combat climate challenges. It is known that about 15–30% of any fertilizer packed in a PC-CRF does not get released due to the concentration gradient difference across the polymer coatings. To release the trapped fertilizer(s), it is desired that polymer-based coatings should biodegrade after the fertilizer is completely released into the soil. This review has aimed to provide a comprehensive account for various biodegradable polymers/blends derived either from natural or synthetic sources which are cited in the literature for PC-CRFs. In addition, this review covers the discussion on their classification criteria, trends in the processes of fertilizer coatings, methodological issues for their biodegradation assessment, coating attributes that affect the biodegradability and an outlook into their biodegradation kinetic models that involve enzymes and microbial processes. It also concludes that experimental as well as modeling data are insufficient to assess the biodegradation contribution of the overall nutrient release in PC-CRFs.

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.

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.

scholarly journals Growth of the Aquatic Plant Southern Naiad in Varying Percentages of Sand and Controlled-release Fertilizer

2018 ◽  
Vol 28 (3) ◽  
pp. 252-256
Author(s):  
Heather Hasandras ◽  
Kimberly A. Moore ◽  
Lyn A. Gettys
Keyword(s):  
Controlled Release ◽  
Aquatic Plants ◽  
Aquatic Plant ◽  
Invasive Plant ◽  
Hydrilla Verticillata ◽  
Dry Weight ◽  
Shoot Dry Weight ◽  
Exotic Invasive ◽  
Production Techniques ◽  
Controlled Release Fertilizers

Native aquatic plants are important to maintaining a balanced ecosystem, but they often are displaced by exotic invasive plant species. The research on the control and growth of the invasive aquatic species hydrilla (Hydrilla verticillata) using sand substrates and controlled-release fertilizers (CRF) provides a potential production technique for other aquatic plants. We questioned if we could use hydrilla production techniques to grow southern naiad (Najas guadalupensis), a Florida-native aquatic plant that is often mistaken for hydrilla. We grew southern naiad cuttings in containers filled with 100:0, 75:25, 50:50, 25:75, or 0:100 coarse builder’s sand and sphagnum moss (by volume). Before planting, containers were fertilized with 0, 1, 2, or 4 g·kg−1 CRF (15N–4P–10K). Containers were submerged in large storage tubs filled with rainwater and grown for 8 weeks. Southern naiad shoot dry weight was greater in the 100% sand substrate than that in the 0% sand substrate. Substrate electrical conductivity (EC) levels were greater in the 0% sand with no difference among the other substrates. Shoot and root dry weight of plants fertilized with 1–2 g·kg−1 CRF were greater than 0 or 4 g·kg−1 CRF. Substrate EC also increased as fertilizer rate increased, with the highest EC observed at 4 g·kg−1 CRF. Based on our results, we would suggest growing southern naiad in substrates with 100% sand and fertilized with 1–2 g·kg−1 CRF.

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 TIME-RELEASE FERTILIZERS AND MEDIA AFFECT GROWTH OF CONTAINER-GROWN LAGERSTROEMIA AND LIGUSTRUM

HortScience ◽  
1992 ◽  
Vol 27 (6) ◽  
pp. 601f-601
Author(s):  
Houchang Khatamjan ◽  
Sudeep Vyapari
Keyword(s):  
Controlled Release ◽  
Dry Weight ◽  
Peat Moss ◽  
Growing Media ◽  
Ph Values ◽  
Shoot Dry Weight ◽  
Media Types ◽  
One Year ◽  
Controlled Release Fertilizers

One-year-old liners of Firebird crape myrtle (Lagerstroemia indica L. 'Firebird') and Vicary golden privet (Ligustrum X vicaryi) were planted in 7.6 liter containers. The growing media consisted of 3 pinebark: 1 Canadian peat moss: 1 sand and 3 sawdust: 1 Canadian peat moss: 1 sand (v/v/v). Both media were amended with NH4NO3 and dolomite. Several controlled release fertilizers at varying rates were incorporated into each medium prior to planting. Thirty, 60 and 90 days after planting, leachate samples were collected and tested for E.C. and pH. Fertilizer Sierra (17-6-10) and Osmocote (18-7-13) resulted in maximum shoot dry weight with both species and media types followed by Osmocote (24-4-8) and Escote (20-4-11). Plants grew equally well in pinebark and sawdust medium. After 30 and 60 days leachate from Sierra (17-6-10) had highest E.C. levels. Osmocote (18-7-13 and 24-4-8) recorded highest E.C. at 90 day sampling date. The sawdust medium had higher pH values than the pinebark.

Release of Phosphorus by Certain Benthic Invertebrates

1981 ◽  
Vol 38 (8) ◽  
pp. 978-981 ◽  
Author(s):  
Wayne S. Gardner ◽  
Thomas F. Nalepa ◽  
Michael A. Quigley ◽  
John M. Malczyk
Keyword(s):  
Benthic Invertebrates ◽  
Lake Michigan ◽  
Nutrient Release ◽  
Dry Weight ◽  
Inorganic Phosphorus ◽  
Benthic Invertebrate ◽  
Phosphorus Release ◽  
Release Rates ◽  
Temperature Regimes ◽  
Two Temperature

Phosphate release rates by Stylodrilus heringianus, tubificids, and Chironomus spp. were quantified in laboratory experiments by incubating the animals in wet sand under two temperature regimes (5 and 20 °C) and under two nutritional states (full and empty guts). Inorganic phosphorus release rates (± SE) for animals incubated 24 h ranged from 0.12 ± 0.02 (n = 5) nmol phosphorus (P)∙(mg ash-free dry weight)−1∙h−1 for S. heringianus beginning with cleared guts at 5 °C to 0.81 ± 0.09 (n = 5) nmol P∙(mg ash-free dry weight)−1∙h−1 for chironomids beginning with full guts at 20 °C. Calculations based on total invertebrate bio-mass and mean basal release rate suggest that benthic invertebrate excretion could account for most P released from aerobic Lake Michigan sediments.Key words: phosphorus, benthic invertebrates, macroinvertebrates, excretion, nutrients, sediments, nutrient release

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