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.

Film-mulched maize production: response to controlled-release urea fertilization

2017 ◽  
Vol 155 (8) ◽  
pp. 1299-1310 ◽  
Author(s):  
J. M. GUO ◽  
J. Q. XUE ◽  
A. D. BLAYLOCK ◽  
Z. L. CUI ◽  
X. P. CHEN
Keyword(s):  
Controlled Release ◽  
Production Systems ◽  
Supply And Demand ◽  
N Uptake ◽  
N Fertilization ◽  
N Recovery ◽  
N Losses ◽  
Maize Production ◽  
N Supply ◽  
Controlled Release Urea

SUMMARYOptimal nitrogen (N) management for maize in the film-mulched production systems that are widely used in dryland agriculture is difficult because top-dressing N is impractical. The current research determined how matching N supply and demand was achieved before and after silking stages, when single applications of controlled release urea (CRU) were combined with conventional urea in film-mulched maize production. The CRU: urea mixture was applied in a 1 : 2 or 2 : 1 ratio and all three fertilizer regimes (urea alone and CRU: urea at 1 : 2 or 2 : 1) were applied at N rates of 180 and 240 kg/ha over 2 years. The 1 : 2 CRU: urea mixture, applied once at 180 kg N/ha, was found to synchronize N supply with demand, thereby reducing N losses. The highest grain yields (11·8–12·0 t/ha), N uptake (232–239 kg/ha), N recovery (65·8–67·7%) and high net economic return were achieved with this regime. These results indicate that a single application of a mixture of CRU and urea can synchronize N supply with demand and provide higher yields and profits than conventional N fertilization in film-mulched maize systems.

Nitrogen dynamics under growth chamber conditions as influenced by method of alfalfa termination 2. Plant-available N release

1998 ◽  
Vol 78 (2) ◽  
pp. 261-266 ◽  
Author(s):  
R. M. Mohr ◽  
H. H. Janzen ◽  
M. H. Entz
Keyword(s):  
Nitrogen Uptake ◽  
N Uptake ◽  
Soil Surface ◽  
Growth Chamber ◽  
Nitrogen Accumulation ◽  
Herbicide Application ◽  
Hordeum Vulgare L ◽  
Available N ◽  
N Release ◽  
Barley Crop

Herbicide application has been proposed as an alternative to tillage for termination of established alfalfa (Medicago sativa L.) stands but it may alter the pattern and amount of N released from alfalfa residues. A controlled environment study was conducted to investigate the effect of termination technique on the availability of N to four barley (Hordeum vulgare L.) crops. Four treatments consisting of a factorial combination of two termination methods (chemical, mechanical) and two methods of residue placement (surface, incorporated) were established. Nitrogen uptake by the four consecutive crops of barley was measured during a 125-d period after termination. Termination method, particularly residue placement, strongly affected N release from alfalfa residues. Nitrogen accumulation by the initial barley crop accounted for >60% of cumulative N uptake in incorporated treatments compared with 39% and 24% for herbicide and tillage treatments in which alfalfa residue was surface applied. Herbicide application also slightly increased N uptake by the initial barley crop. Nitrogen uptake by subsequent barley crops was not affected by termination method; however, cumulative N uptake remained substantially greater for incorporated treatments throughout the 125 d experiment. Effects of residue particle size on N release from alfalfa residues were small. These results suggest that herbicide termination in which residue is retained on the soil surface may reduce the short-term plant-available N supply. Provided that mineralization is sufficient to meet the N needs of subsequent crops, maintaining a smaller reservoir of soil inorganic N may be beneficial in reducing the potential for leaching or denitrification losses. Key words: Plant-available N, termination method, alfalfa, herbicide, tillage, growth chamber

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.

The course of fertilizer nitrogen uptake by rainfed sugarcane in Mauritius

1994 ◽  
Vol 122 (3) ◽  
pp. 385-391 ◽  
Author(s):  
K. F. Ng Kee Kwong ◽  
J. Deville
Keyword(s):  
Dry Matter ◽  
N Uptake ◽  
N Recovery ◽  
Dry Matter Accumulation ◽  
Fertilizer N ◽  
N Losses ◽  
Total N ◽  
Fertilizer N Recovery ◽  
The Difference ◽  
Fertilizer N Uptake

SUMMARYThe patterns of N uptake and dry matter synthesis by sugarcane (Saccharum hybrid spp.) were studied at four locations in Mauritius with 15N–labelled ammonium sulphate (100 kg N/ha) applied either in a single dressing in September or in two split applications in September and the following February. More than 80% of the total N recovered at harvest (100–120 kgN/ha) was absorbed by the sugarcane during an active uptake period from October to January. Split application prolonged this active N uptake until April only and had no effect on dry matter accumulation. While total Nabsorbed by above-ground sugarcane showed no decline over time, 10–20 kg N/ha of the 15N–labelled N was lost from the green tops even when the N was applied on two occasions. The fertilizer N losses from above-ground sugarcane were, however, not evident when fertilizer N recovery with time was studied by the difference method. In view of the observed losses of fertilizer N from the aerial parts of sugarcane, measurement of fertilizer N recovery at harvest by the N isotope dilution technique underestimates fertilizer N uptake by sugarcane and attributes too large a fraction of N loss to denitrification/volatilization of NH3.

scholarly journals Growth and Nitrogen Partitioning, Recovery, and Losses in Bermudagrass Receiving Soluble Sources of Labeled 15Nitrogen

1999 ◽  
Vol 124 (6) ◽  
pp. 719-725 ◽  
Author(s):  
G.A. Picchioni ◽  
Héctor M. Quiroga-Garza
Keyword(s):  
Cynodon Dactylon ◽  
N Uptake ◽  
N Fertilization ◽  
Nitrogen Partitioning ◽  
N Recovery ◽  
Natural Light ◽  
Fertilizer N ◽  
N Losses ◽  
N Source ◽  
Total Plant

Two greenhouse studies were conducted to trace the fate of fertilizer N in hybrid bermudagrass [Cynodon dactylon (L.) Pers. × C. transvaalensis Burtt-Davy `Tifgreen'], and to estimate total plant N recovery and losses. The first experiment was performed during winter, with artificial light supplementing natural light to provide a photoperiod of 13.6 to 13.8 hours. The second experiment was conducted during summer and fall under only natural light conditions, with a progressively decreasing photoperiod of 13.7 to 11.1 hours. Urea (UR), ammonium sulfate (AS), and ammonium nitrate (AN) were labeled at 2 atom% 15N, and applied at N rates of 100 or 200 kg·ha-1 for 84 days (divided into six equal fractions and applied every 14 days). Fertilizer N source did not affect total dry matter (DM) accumulation by the plant components, but the high N rate increased clipping DM production under the longer photoperiod. Under the decreasing photoperiod, overall DM production was reduced, and clipping DM production was unaffected by increased N rate. Average N concentration of clippings varied between N sources, ranging from a high of 38.6 g·kg-1 DM with AS to a low of 34.7 g·kg-1 for UR. In Expt. 1, the greatest total plant N recovery [clippings, verdure (shoot material remaining after mowing), and thatch plus roots] occurred with AS (78.5%) and the lowest with UR (65.9%). In Expt. 2, these values declined to 53.0% and 38.0%, respectively. Urea fertilization resulted in the greatest N losses as a fraction of the N applied (33.6% to 61.5%) and AS fertilization the lowest (20.7% to 46.3%). In view of the greater N losses, UR may be a less suitable soluble N source for bermudagrass fertilization within the conditions of this study. In addition, late-season N fertilization may result in a significant waste of fertilizer N as bermudagrass progresses into autumnal dormancy when temperature, photoperiod, and irradiance decline and cause reduction in growth and N uptake.

scholarly journals Prediction of Controlled-release Fertilizer Nitrogen Release Using the Pouch Field and Accelerated Temperature-controlled Incubation Methods in Sand Soils

HortScience ◽  
2014 ◽  
Vol 49 (12) ◽  
pp. 1575-1581 ◽  
Author(s):  
Luther C. Carson ◽  
Monica Ozores-Hampton ◽  
Kelly T. Morgan ◽  
Jerry B. Sartain
Keyword(s):  
Controlled Release ◽  
Management Practice ◽  
Field Method ◽  
Vegetable Production ◽  
Tomato Production ◽  
Controlled Release Fertilizer ◽  
N Release ◽  
Coated Urea ◽  
Temperature Controlled ◽  
Correlation Process

Controlled-release fertilizers (CRFs), a vegetable production best management practice in Florida, are soluble fertilizers (SFs) coated with a polymer, resin, or a hybrid of polymer coating sulfur-coated urea. In 1994, a Controlled Release Fertilizer Taskforce developed an accelerated temperature-controlled incubation method (ATCIM) to predict column-incubated CRF nitrogen (N) release for regulatory purposes. Determination of CRF field N release uses a field method such as a pouch field study, which requires multiple samples and high costs for laboratory N analysis. If the ATCIM may be used to predict CRF N release in the field, then vegetables growers will have a faster and lower-cost method to determine N release compared with the pouch field method. Therefore, the objective of this study was to evaluate the correlation of the ATCIM and the pouch field method as a predictor of N release from CRFs in tomato production in Florida. In 2011 and 2013, 12 and 14 CRFs, respectively, were incubated in pouches placed in polyethylene mulched raised beds in Immokalee, FL, and extracted in the ATCIM during 2013. The ATCIM CRF results were used individually and grouped by release duration to create predicted N release curves in a two-step correlation process. The two-step processes predicted the percentage N release of individual CRF with R2 of 0.95 to 0.99 and 0.61 to 0.99 and CRFs grouped by release duration with R2 of –0.64 to 0.99 and –0.38 to 0.95 in 2011 and 2013, respectively. Modeling CRF N release grouped by release duration would not be recommended for CRF 180-d release (DR), because coating technologies behaviors differ in response to high fall soil temperature in polyethylene mulched beds. However, with further model calibration, grouping CRFs of 90 to 140 DR to simulate the CRF N release profile may allow the ATCIM to predict CRF N release without performing the pouch field method, which currently negated the usefulness of the ATCIM in a tomato production system.

scholarly journals Biodegradable Polymer Coated Granular Urea Slows Down N Release Kinetics and Improves Spinach Productivity

Polymers ◽  
2020 ◽  
Vol 12 (11) ◽  
pp. 2623 ◽  
Author(s):  
Bilal Beig ◽  
Muhammad Bilal Khan Niazi ◽  
Zaib Jahan ◽  
Salik Javed Kakar ◽  
Ghulam Abbas Shah ◽  
...  
Keyword(s):  
Biodegradable Polymers ◽  
Release Rate ◽  
Release Kinetics ◽  
N Uptake ◽  
Gum Arabic ◽  
Polymeric Materials ◽  
Utilization Efficiency ◽  
N Recovery ◽  
N Utilization ◽  
N Release

Low nitrogen (N) utilization efficiency due to environmental N losses from fertilizers results in high-cost on-farm production. Urea coating with biodegradable polymers can prevent these losses by controlling the N release of fertilizers. We calculated N release kinetics of coated granular with various biodegradable polymeric materials and its impact on spinach yield and N uptake. Different formulations were used, (i) G-1: 10% starch + 5% polyvinyl alcohol (PVA) + 5% molasses; (ii) G-2: 10% starch + 5% PVA + 5% paraffin wax (PW); (iii) G-3: 5% gelatin + 10% gum arabic + 5% PW; (iv) G-4: 5% molasses + 5% gelatin + 10% gum arabic, to coat urea using a fluidized bed coater. The morphological and X-ray diffraction (XRD) analyses indicated that a uniform coating layer with no new phase formation occurred. In the G-2 treatment, maximum crushing strength (72.9 N) was achieved with a slowed-down N release rate and increased efficiency of 31%. This resulted in increased spinach dry foliage yield (47%), N uptake (60%) and apparent N recovery (ANR: 130%) from G-2 compared to uncoated urea (G-0). Therefore, coating granular urea with biodegradable polymers is a good choice to slower down the N release rate and enhances the crop yield and N utilization efficiency from urea.

Influence of controlled-release urea on seed yield and N concentration, and N use efficiency of small grain crops grown on Dark Gray Luvisols

2010 ◽  
Vol 90 (2) ◽  
pp. 363-372 ◽  
Author(s):  
S S Malhi ◽  
Y K Soon ◽  
C A Grant ◽  
R. Lemke ◽  
N. Lupwayi
Keyword(s):  
Controlled Release ◽  
Seed Yield ◽  
N Uptake ◽  
N Recovery ◽  
No Tillage ◽  
Split Application ◽  
N Concentration ◽  
Use Efficiency ◽  
N Use ◽  
Controlled Release Urea

Field experiments were conducted on Dark Gray Luvisolic soils (Typic Cryoboralf) from 2004 to 2006 (wheat-canola-barley rotation) near Star City, Saskatchewan, and from 2004 to 2007 (barley-canola-wheat-barley rotation) near Beaverlodge, Alberta. The aim was to compare the effects of controlled-release urea (CRU) vs. conventional urea (hereafter called urea) on seed yield and N (i.e., protein) concentration, and N use efficiency (NUE). The treatments were combinations of tillage system [conventional tillage (CT) and no tillage (NT)], and N source (urea, CRU and a blended mixture), placement method (spring-banded, fall-banded and split application) and application rate (0-90 kg N ha-1). There was no tillage × fertilizer treatment interaction on the measured crop variables. Seed yield and crop N uptake and, to a lesser degree, seed N concentration generally increased with N application to 90 kg N ha-1. Fall-banded CRU or urea generally produced lower crop yield and N uptake than spring-banded CRU or urea. Split application of urea (half each at seeding and tillering) resulted in higher seed yield and N concentration in at least 3 of 7 site-years than did CRU and urea applied at a similar rate. A blend of urea and CRU was as effective as spring-banded CRU (at Star City only). Seed yield, N recovery and NUE were higher with spring-banded CRU than urea in 2 site-years, and similar to urea in other site-years. We conclude that for boreal soils of the Canadian prairies, spring-banded CRU is as effective as urea, and in some years more effective, in increasing crop yield and N recovery; however, urea split application can be even more effective in addition to having an advantage in managing risk.Key words: Controlled-release urea, Gray Luvisol, nitrogen source, nitrogen recovery, nitrogen use efficiency, tillage systems

scholarly journals Morphophysiological Traits, Biochemical Characteristic and Productivity of Wheat under Water and Nitrogen-Colimitation: Pathways to Improve Water and N Uptake

2020 ◽  
Author(s):  
Nawab Ali ◽  
Mohammad Akmal
Keyword(s):  
N Uptake ◽  
Maximum Yield ◽  
Growth Yield ◽  
Crop Productivity ◽  
Wheat Crop ◽  
Limiting Factor ◽  
N Recovery ◽  
N Availability ◽  
N Losses ◽  
Environmental Consequences

Drought stress is the most prominent limiting factor and abiotic stress that manipulates the physiological pathway, biochemical traits and hence negatively affects wheat crop productivity. The global nitrogen (N) recovery indicated that about two-fifths of N inputs are lost in the ecosystems through emission, denitrification, gaseous loss, leaching, surface runoff and volatilization etc. Farmers are using higher rates of N to harvest maximum yield but about 50–60% of applied N to crop field is not utilized by the plants and are lost to environment causing environmental pollution. These deleterious environmental consequences need to be reduced by efficient management of N and/or water. N-availability is often regulated by soil water; hence crop is experiencing N- and water-limitation simultaneously. There is great impetus to optimize their uptake through interconnectedness of water and N for yield determination of wheat because of the water scarcity and N losses. It is further advocate that there is need to investigate the intricate role of economizing N rate and water simultaneously for wheat crop growth, yield and backing quality may be beneficial to be investigate.

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.

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