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.

scholarly journals Nitrogen Release Characteristics of a Bag Controlled Release Fertilizer

2019 ◽  
Vol 2 (1) ◽  
Author(s):  
Yi Zhong ◽  
Renyi Gui ◽  
Zhuangzhuang Qian ◽  
Shunyao Zhuang
Keyword(s):  
Controlled Release ◽  
Evaluation Method ◽  
Ammonia Volatilization ◽  
Slow Release ◽  
Ammonia Emission ◽  
N Leaching ◽  
Nitrogen Release ◽  
N Release ◽  
Slow Release Fertilizers ◽  
Controlled Release Fertilizers

Slow release fertilizers are designed to enhance crop yield and minimizing the loss of nitrogen (N) to environment. However, N release in leaching and loss in ammonia emission from bag controlled release fertilizers have not been previously evaluated under the standardized conditions in soil. Accordingly, a laboratory study was conducted to evaluate the characteristics of N release from a bag controlled fertilizer with 1, 3, 5 and 7 rows of hole (B-1, B-3, B-5, B-7) and a kraft bag without hole (B-W). The results showed that the amount of N leaching of B-1, B-3, B-5, B-7 and B-W were significantly lower than urea fertilizer without bag (U). The maximum N release from the fertilizers followed the order: U (83.16%) > B-7 (54.61%) > B-5 (54.02%) > B-W (51.51%) > B-3 (48.87%) > B-1 (38.60%) during the experimentation. Compared with U treatment, ammonia volatilization losses were significantly decreased by B-1, B-3, B-5, B-7 and B-W treatments. Based on N release and loss, a suitable bag with holes should be considered in practice when using the bag controlled fertilizer to meet an environment good objective. The evaluation method merits further study combined with field experiment.

scholarly journals Nitrogen Release Characteristics from Controlled-release Fertilizers

HortScience ◽  
1996 ◽  
Vol 31 (4) ◽  
pp. 606f-606
Author(s):  
Raul I. Cabrera
Keyword(s):  
Controlled Release ◽  
Nitrate Concentration ◽  
Nitrogen Release ◽  
Ambient Temperatures ◽  
Temperature Responsive ◽  
N Release ◽  
Controlled Release Fertilizers ◽  
Grade 8

Seven nursery grade (8- to 9-month duration), polymer-coated, controlled-release fertilizers (CRF) were topdressed or incorporated to a peat: sand: vermiculite medium to yield the same amount of N per container. The pots were uniformly irrigated with DI water every week. Leachates were collected and analyzed for N (ammonium plus nitrate) concentration. Two distinct N release (NR) patterns were observed over the 180-day experiment. Osmocote 18–6–12FS, Prokote-P 20–3–10, Osmocote 24–4–8HN, and Polyon 25–4–12 exhibited a NR pattern that closely followed changes in average daily ambient temperatures (AT) over the season. This relationship was curvilinear in nature, with NR being highly responsive to AT up to 25°C. Conversely, Osmocote 18–6–12, Nutricote 18–6–8 (270), and Woodace 20–4–12 showed a stable NR pattern over a wider range of AT, with NR rates 30% to 60% lower than those in the temperature-responsive CRF. Incorporation produced significantly higher cumulative N releases than topdressing but without effect on the actual pattern of NR over the season. Regardless of the N formulation in the CRF, >80% of the N recovered in the leachates was in the nitrate form.

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 Methods for Determining Nitrogen Release from Controlled-release Fertilizers Used for Vegetable Production

2012 ◽  
Vol 22 (1) ◽  
pp. 20-24 ◽  
Author(s):  
Luther C. Carson ◽  
Monica Ozores-Hampton
Keyword(s):  
Weight Loss ◽  
Controlled Release ◽  
N Uptake ◽  
Growth Chamber ◽  
N Recovery ◽  
Vegetable Production ◽  
Field Methods ◽  
N Losses ◽  
N Release ◽  
Plastic Bag

The purpose of this article is to review nitrogen (N) controlled-release fertilizer (CRF) research methods used to measure nutrient release from CRFs. If CRF-N release patterns match vegetable crop needs, crop N uptake may become more efficient, thus resulting in similar or greater yields, reduced fertilizer N needs, and reduced environmental N losses. Three methods categories to estimate N release are: laboratory; growth chamber, greenhouse, or both; and field methods. Laboratory methods include a standard and accelerated temperature-controlled incubation methods (TCIMs); methods incubate CRF using selected time periods, temperatures, and/or sampling methods. Accelerated TCIMs, in contrast to the standard method, allow for shorter incubation periods. Growth chamber and greenhouse methods, including column and plastic bag studies, may be used to test new CRF products in conditions similar to particular vegetable production systems. However, the column method predicts N release from CRFs more effectively than the plastic bag method because of ammonia volatilization and lower N recovery rates associated with the bag method. Both field methods, pot-in-pot and pouch methods, are viable vegetable research options. The pouch method measures N remaining in the CRF prill and the pot-in-pot method measures N released from the CRF, thus each method can be applied to different research objectives. Nitrogen released during incubation may be measured using methods such as total Kjeldahl N (TKN), prill weight loss, combustion, colorimetric, or ion-specific electrodes. The prill weight loss method is the least expensive but can only be used with urea CRF. Thus, the CRF-N source(s) and research objectives will determine the appropriate N analysis method. More research needs to be completed on correlations of field and laboratory CRF extractions. Field release methods should be considered the most reliable indicator of CRF-N performance until a laboratory method reliably predicts CRF-N expected field response.

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.

Optimization and Validation of an Accelerated Laboratory Extraction Method to Estimate Nitrogen Release Patterns of Slow- and Controlled-Release Fertilizers

2014 ◽  
Vol 97 (3) ◽  
pp. 661-676 ◽  
Author(s):  
L Carolina Medina ◽  
Jerry B Sartain ◽  
Thomas A Obreza ◽  
William L Hall ◽  
Nancy J Thiex
Keyword(s):  
Controlled Release ◽  
Extraction Method ◽  
Nutrient Release ◽  
Portion Size ◽  
Effect Of Temperature ◽  
Extraction Temperature ◽  
Test Portion ◽  
N Release ◽  
Slow Release Fertilizers ◽  
Controlled Release Fertilizers

Abstract Several technologies have been proposed to characterize the nutrient release and availability patterns of enhanced-efficiency fertilizers (EEFs), especially slow-release fertilizers (SRFs) and controlled-release fertilizers (CRFs) 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 EEF product. Despite previous efforts to characterize EEF materials, no validated method exists to assess their nutrient release patterns. However, the increased use of EEFs in specialty and nonspecialty markets requires an appropriate method to verify nutrient claims and material performance. A series of experiments were conducted to evaluate the effect of temperature, fertilizer test portion size, and extraction time on the performance of a 74 h accelerated laboratory extraction method to measure SRF and CRF nutrient release profiles. Temperature was the only factor that influenced nutrient release rate, with a highly marked effect for phosphorus and to a lesser extent for nitrogen (N) and potassium. Based on the results, the optimal extraction temperature set was: Extraction No. 1—2:00 h at 25°C; Extraction No. 2—2:00 h at 50°C; Extraction No. 3—20:00 h at 55°C; and Extraction No. 4—50:00 h at 60°C. Ruggedness of the method was tested by evaluating the effect of small changes in seven selected factors on method behavior using a fractional multifactorial design. Overall, the method showed ruggedness for measuring N release rates of coated CRFs.

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 Using Nutrient Uptake Patterns to Develop Efficient Nitrogen Management Strategies for Vegetables

1999 ◽  
Vol 9 (4) ◽  
pp. 601-606 ◽  
Author(s):  
Charles A. Sanchez ◽  
Thomas A. Doerge
Keyword(s):  
Controlled Release ◽  
Crop Production ◽  
Management Practice ◽  
Management Strategies ◽  
N Fertilization ◽  
Nitrogen Management ◽  
N Losses ◽  
Uptake Studies ◽  
N Management ◽  
Controlled Release Fertilizers

Nitrogen (N) in a soil that is not immediately taken up by a crop is subject to leaching, denitrification and other mechanisms of loss. Nitrogen uptake studies identify the total amount of N accumulated by the crop and the period of peak demand. This information can be used to devise management strategies aimed at supplying N preceding anticipated uptake. Split sidedress application, fertigation, and use of controlled release fertilizers (CRN) are all viable options for N management, depending on the crop production scenario and available infrastructure. Soil and plant tissue testing can be useful feedback tools for adjusting N applications for soil contributions of N and unexpected N losses. Efficient irrigation is of paramount importance in achieving efficient N fertilization regardless of management practice.

scholarly journals Controlled-release Fertilizers for Vegetable Production in the Era of Best Management Practices: Teaching New Tricks to an Old Dog

2005 ◽  
Vol 15 (1) ◽  
pp. 36-46 ◽  
Author(s):  
Eric H. Simonne ◽  
Chad M. Hutchinson
Keyword(s):  
Controlled Release ◽  
Best Management Practices ◽  
Management Practices ◽  
Calcium Nitrate ◽  
Vegetable Production ◽  
Available Nitrogen ◽  
Cost Share ◽  
Best Management ◽  
N Release ◽  
Controlled Release Fertilizers

Best management practices (BMPs) for vegetable crops are under development nationwide and in Florida. One goal of the Florida BMP program is to minimize the possible movement of nitrate-nitrogen from potato (Solanum tuberosum) production to surface water in the St. Johns River watershed without negatively impacting potato yields or quality. Current fertilizer BMPs developed for the area focus on fertilizer rate. Controlled-release fertilizers (CRF) have long been a part of nutrient management in greenhouse and nursery crops. However, CRFs have been seldom used in field-vegetable production because of their cost and release characteristics. Nutrient release curves for CRFs are not available for the soil moisture and temperature conditions prevailing in the seepage-irrigated soils of northern Florida. Controlled-leaching studies (pot-in-pot) in 2000 and 2001 have shown that plant-available nitrogen (N) was significantly higher early in the season from ammonium nitrate, calcium nitrate and urea compared to selected CRFs. However, N release from off-the-shelf and experimental CRFs was too slow, resulting in N recoveries ranging from 13% to 51%. Cost increase due to the use of CRFs for potato production ranged from $71.66 to $158.14/ha ($29 to $64 per acre) based on cost of material and N application rate. This higher cost may be offset by reduced application cost and cost-share pro-grams. Adoption of CRF programs by the potato (and vegetable) industry in Florida will depend on the accuracy and predictability of N release, state agencies' commitment to cost-share programs, and CRFs manufacturers' marketing strategies. All interested parties would benefit in the development of BMPs for CRFs.

scholarly journals Combining Organic Fertilizer With Controlled-Release Urea to Reduce Nitrogen Leaching and Promote Wheat Yields

2021 ◽  
Vol 12 ◽  
Author(s):  
Xiuyi Yang ◽  
Chao Zhang ◽  
Xiaoli Ma ◽  
Qianjin Liu ◽  
Juan An ◽  
...  
Keyword(s):  
Controlled Release ◽  
Wheat Yield ◽  
Total Carbon ◽  
N Leaching ◽  
Total Carbon Content ◽  
Total N ◽  
Urea Treatment ◽  
Average Maximum ◽  
Significant Difference ◽  
Controlled Release Urea

Soil deterioration, low nitrogen use efficiency (NUE), and environmental risks caused by excessive chemical N fertilizer use are key factors restricting sustainable agriculture. It is extremely critical to develop effective N management strategies that consider both environmental and agronomic benefits. From 2017 to 2019, a field experiment was conducted to assess the effects of combinations of organic fertilizers (OF, provided at 30, 50, and 70% of the total applied N) and controlled-release urea (CU) on the NUE, N leaching and wheat yield compared with the effects of urea and CU. The results suggested that OF released N slowly in the early stage and showed a significant residual effect, while CU released N quickly in the first 2 months. The OF substitutes with 30–50% CU increased wheat yield by 4.2–9.2%, while the 70%OF+30%CU treatment showed no significant difference relative to the urea treatment. The average maximum apparent NUE recovery (50.4%) was achieved under the 50%OF+50%CU treatment, but the partial factor productivity was not affected by the N type. As the OF application rate increased, the total carbon content increased, and the total N value decreased. The NO3−-N and NH4+-N concentrations in the OF+CU treatments were lower before the jointing stage but higher from the grain-filling to mature stages than those in the urea treatment. NO3−-N and NH4+-N were mainly concentrated in the 0–60-cm layer soil by OF substitution, and N leaching to the 60–100-cm soil layer was significantly reduced. Hence, the results suggest that the combination of 30–50% OF with CU synchronizes absorption with availability due to a period of increased N availability in soils and proved to be the best strategy for simultaneously increasing wheat production and reducing N leaching.

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