scholarly journals Rates of Ammonium-nitrogen, Nitrate-nitrogen, Phosphorus, and Potassium from Two Controlled-release Fertilizers under Different Substrate Environments

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.


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.


2017 ◽  
Vol 27 (5) ◽  
pp. 639-643 ◽  
Author(s):  
Carey Grable ◽  
Joshua Knight ◽  
Dewayne L. Ingram

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.


2007 ◽  
Vol 17 (2) ◽  
pp. 174-177 ◽  
Author(s):  
Timothy K. Broschat

Four different organic mulches were applied to 1-m2 plots of Margate fine sand soil that were irrigated three times per week. A 8N–0.9P–10K–4Mg controlled-release fertilizer was applied above or below these mulches to determine the effects of fertilizer placement on weed growth and soil pH, nitrate–nitrogen, ammonium–nitrogen, potassium (K), and magnesium (Mg) concentrations. Unfertilized plots were used to determine mulch effects on soil pH and nutrient content. Fertilizer placement generally had no effect on any of these soil fertility parameters nor did it affect weed numbers. Cypress mulch increased soil K concentrations, and pine bark and eucalyptus mulch increased soil Mg over that of unmulched plots when no fertilizer was applied. The presence of any mulch type greatly reduced weed numbers over that of unmulched plots.


1967 ◽  
Vol 39 (3) ◽  
pp. 148-155
Author(s):  
Erkki Aura

The placement of fertilizer was studied in the field trial on a clay soil in Southern Finland. The placement of fertilizer in the depth of 8 cm gave 28 per cent greater grain yield of spring wheat, and the placement in the depth of 12 cm 26 per cent greater grain yield than the surface dressing. The growth of shoots on the soil receiving placement was much better than on the soil receiving surface dressing. The results of shoot analyses showed that the placement caused a much greater uptake of nutrients than the surface dressing. The uptake of nitrogen was relatively most increased by the placement, somewhat less that of potassium and least that of phosphorus. The ripening of wheat was speeded up by the placement, which probably was due to the better early uptake of nitrogen and to the better uptake of phosphorus by means of the placing. The superiority of the placement to the surface dressing could be explained by the distribution of nutrients in the experimental soil during the dry early part of the growth season. A great deal of fertilizer nitrogen, phosphorus and potassium remained near the surface of the soil receiving surface dressing, and plants were not able to take up nutrients from the dry surface layer. On the contrary, the placed nutrients were deeper, in moister soil and better within the reach of wheat roots. Any movement of ammonium nitrogen was not found by the used methods. Nitrate nitrogen appeared to move to a greater extent particularly in the irrigated plots.


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.


1957 ◽  
Vol 10 (3) ◽  
pp. 253 ◽  
Author(s):  
WG Slater ◽  
DW Goodall

Lettuce plants grown in sand culture, and receiving nitrogen, phosphorus, and potassium at five levels in all combinations, were analysed at different stages of growth for total, soluble, and nitrate nitrogen. An attempt was made to relate these analytical data to the subsequent response (in dry matter production) shown by the plants when a further amount of nitrogen was supplied.


Author(s):  
Flávia Werner ◽  
André Sampaio Ferreira ◽  
Alvadi Antonio Balbinot Junior ◽  
Adilson de Oliveira Junior ◽  
Julio Cezar Franchini ◽  
...  

Abstract: The objective of this work was to determine the nitrogen, phosphorus, and potassium released by N-fertilized Urochloa brizantha straw, desiccated before sowing of no-tillage soybean (Glycine max) in succession. The pasture was grown in three paddocks, each fertilized with one N rate (0, 150, or 300 kg ha-1), and assessed at two desiccation periods (60 or 15 days before soybean sowing), in four replicates. Nitrogen fertilization of U. brizantha pasture increases N and K cycling and the release of these nutrients to the subsequent soybean crop. The quantity of K released by U. brizantha straw fertilized with 150 or 300 kg ha-1 N (about 80 kg ha-1 K) offsets that contained in an export of up to 4 Mg ha-1 soybean grains, assuming zero K losses in the system. An early desiccation of the U. brizantha pasture does not improve K uptake by the soybean crop, since 50% of the nutrient is released in the first 20 days after desiccation. The dynamics of P release from U. brizantha straw (about 6 to 10 kg ha-1 during the soybean crop) is not influenced by N fertilization and the time of pasture desiccation.


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