Longevities and nitrogen, phosphorus, and potassium release patterns of polymer‐coated controlled‐release fertilizers at 30°C and 40°C

2000 ◽  
Vol 31 (7-8) ◽  
pp. 959-973 ◽  
Author(s):  
David O. Huett ◽  
Beverley J. Gogel
2005 ◽  
Vol 15 (2) ◽  
pp. 332-335 ◽  
Author(s):  
Timothy K. Broschat

Five-gram (0.18 oz) samples of two controlled-release fertilizers (CRFs), Osmocote 15N–3.9P–10K (8–9 month) (OSM) and Nutricote 18N–2.6P–6.7K (type 180) (NUTR), were sealed into polypropylene mesh packets that were placed on the surface of a 5 pine bark: 4 sedge peat: 1 sand (by volume) potting substrate (PS), buried 10 cm (3.9 inches) deep below the surface of PS, buried 10 cm below the surface of saturated silica sand (SS), or in a container of deionized water only. Containers with PS received 120 mL (4.1 floz) of deionized water three times per week, but the containers with SS or water only had no drainage and were sealed to prevent evaporation. Samples were removed after 2, 5, or 7 months of incubation at 23 °C (73.4 °F) and fertilizer prills were crushed, extracted with water, and analyzed for ammonium-nitrogen (NH4-N), nitrate-nitrogen (NO3-N), phosphorus (P), and potassium (K). Release rates of NO3-N were slightly faster than those of NH4-N and both N ions were released from both products much more rapidly than P or K. After 7 months, OSM prills retained only 8% of their NO3-N, 11% of their NH4-N, 25% of their K, and 46% of their P when averaged across all treatments. Nutricote prills retained 21% of their NO3-N, 28% of their NH4-N, 51% of their K, and 65% of their P. Release of all nutrients from both fertilizers was slowest when applied to the surface of PS, while both products released most rapidly in water only. Release rates in water only exceeded those in SS, presumably due to lower rates of mass flow in SS.


2008 ◽  
Vol 18 (4) ◽  
pp. 671-677 ◽  
Author(s):  
Timothy K. Broschat

In two experiments, pasteurized poultry litter (PPL) was evaluated as a potential substitute for controlled-release fertilizers in the production of container-grown downy jasmine (Jasminum multiflorum), chinese hibiscus (Hibiscus rosa-sinensis), and areca palm (Dypsis lutescens). Downy jasmine and chinese hibiscus generally grew better when provided with PPL as a micronutrient source than with no micronutrients or with an inorganic micronutrient blend (MN). However, areca palm grew poorly with PPL as a fertilizer supplement compared with MN-fertilized areca palm. PPL provided high levels of ammonium nitrogen, phosphorus, and potassium during the first few weeks, but soil solution levels of these elements dropped off rapidly in subsequent weeks. The large amount of phosphorus leached from the containers fertilized with PPL is an environmental concern.


HortScience ◽  
2006 ◽  
Vol 41 (3) ◽  
pp. 780-787 ◽  
Author(s):  
Donald J. Merhaut ◽  
Eugene K. Blythe ◽  
Julie P. Newman ◽  
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.


2016 ◽  
Vol 99 (2) ◽  
pp. 353-359 ◽  
Author(s):  
Nancy Thiex

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.


Materials ◽  
2021 ◽  
Vol 14 (5) ◽  
pp. 1295
Author(s):  
Tariq Labbilta ◽  
Mohamed Ait-El-Mokhtar ◽  
Younes Abouliatim ◽  
Mehdi Khouloud ◽  
Abdelilah Meddich ◽  
...  

Four different phosphate glass formulations (F0, F1, F2, and F3) were developed according o wheat nutrient requirements to be used as controlled-release fertilizers. These glasses contain macro-elements (P2O5-K2O-CaO-MgO), with the addition of microelements (Fe-Mn-Zn-B-Cu-Mo) in each formulation. The effects of these elements’ addition on thermal properties, glass structure, and dissolution behaviors were investigated. Results showed that these glasses are composed essentially of metaphosphate chains and that the addition of micronutrients could change the chemical durability of phosphate glasses. A greenhouse experiment was performed using wheat (Triticum durum L.) to evaluate the efficiency of the four glasses, with or without application of chemical nitrogen (N) (N + VF and VF, respectively). The different formulas were tested using two rates of 0.3 and 1 g per plant. In addition to the vitreous fertilizer formulations, two other treatments were applied: control treatment with no amendment and Nitrogen-Phosphorus-Potassium treatment with the application of the conventional fertilizers on the base of optimal rates. After four months of cultivation, vitreous fertilizers application significantly improved growth (7% to 88%), photosynthetic (8% to 49%) parameters, and yield (29% to 33%) compared to NPK treatment and to the control. It has been found that formulas F1, F2, and F3 may constitute a potential alternative to conventional fertilization due to their positive impact on wheat production and can be used in practice as an environmentally controlled-release fertilizer.


1998 ◽  
Vol 16 (3) ◽  
pp. 182-188
Author(s):  
Kelly M. Groves ◽  
Stuart L. Warren ◽  
Ted E. Bilderback

Abstract Rooted cuttings of Cotoneaster dammeri Schneid ‘Skogholm’ and seedlings of Rudbeckia fulgida Ait. ‘Goldsturm’ were potted into 3.8 liter (4 qt) containers in a pine bark:sand (8:1 by vol) substrate incorporated with 3.5 g (0.12 oz) N per container provided by one of the following five controlled-release fertilizers (CRFs): Meister 21N–3.5P–11.1K (21–7–14), Osmocote 24N–2.0P–5.6K (24–4–7), Scotts 23N–2.0P–6.4K (23–4–8), Sustane 5N–0.9P–3.3K (5–2–4) or Woodace 21N–3.0P–9.5K (21–6–12). Two hundred ml (0.3 in), 400 ml (0.6 in), 800 ml (1.1 in) or 1200 ml (1.7 in) of water was applied once daily (single) or in two equal applications with a 2 hr interval between applications (cyclic). Substrate solutions were collected from containers of cotoneaster 15, 32, 45, 60, 74, 90, 105, and 119 days after initiation (DAI). Irrigation efficiency [(water applied − water leached) ÷ water applied] was determined on the same days. Cyclic application improved irrigation efficiency at 800 ml (1.1 in) and 1200 ml (1.7 in) ≈ 27% compared to a single application. Irrigation efficiencies averaged over the season were 95%, 84%, 62%, and 48% for cotoneaster and 100%, 90%, 72%, and 51% for rudbeckia at 200 ml (0.3 in), 400 ml (0.6 in), 800 ml (1.1 in) and 1200 ml (1.7 in), respectively. NH4-N and NO3-N and PO4-P concentrations in substrate solution decreased with increasing irrigation volume regardless of CRF. Substrate NH4-N concentration decreased throughout the season with most CRFs below 5 mg/liter by 90 DAI. CRFs mainly affected substrate NH4-N and NO3-N concentrations when irrigated with 200 ml (0.3 in) or 400 ml (0.6 in). Substrate NH4-N, NO3-N, and PO4-P solution concentrations were similar for all CRFs at irrigation volume of 1200 ml (1.7 in). Osmocote, Scotts, and Woodace maintained relatively constant substrate solution levels of PO4-P through 60 DAI. By 90 DAI, substrate PO4-P levels were similar regardless of irrigation volume or CRF. Substrate PO4-P concentrations were never in the recommended range of 5 to 10 mg/liter when irrigated with 800 ml (1.1 in) or 1200 ml (1.7 in) regardless of CRF. Solution pH remained in the recommended range of 5.0 to 6.0 for all irrigation volumes and CRFs throughout the entire study with the exception of Sustane.


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