Irrigation Volume, Application, and Controlled-release Fertilizer II. Effect on Substrate Solution Nutrient Concentration and Water Efficiency in Containerized Plant Production

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.

1998 ◽  
Vol 16 (3) ◽  
pp. 176-181
Author(s):  
Kelly M. Groves ◽  
Stuart L. Warren ◽  
Ted E. Bilderback

Abstract An experiment with four volumes of irrigation and five controlled-release fertilizers (CRFs) was conducted to evaluate effects on plant growth and mineral nutrient content. Rooted cuttings of Cotoneaster dammeri ‘Skogholm’ and seedlings of Rudbeckia fulgida ‘Goldsturm’ were grown in 3.8 liter (4 qt) containers in a pine bark:sand substrate (8:1, by vol) incorporated with 3.5 g (0.12 oz) N per container with one of the following five 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). Irrigation volumes of 200 ml (0.3 in), 400 ml (0.6 in), 800 ml (1.1 in), or 1200 ml (1.7 in) were applied once daily (single) or in two equal applications with a two hr interval between irrigation allotments (cyclic). All measured variables were unaffected by irrigation application (cyclic or single). Top dry weight of cotoneaster increased quadratically with increasing irrigation volume for all CRFs. Maximum top dry weight was obtained with 612 ml (0.8 in), 921 ml (1.3 in), 928 ml (1.3 in), 300 ml (0.6 in), or 909 ml (1.3 in) for plants fertilized with Meister, Osmocote, Scotts, Sustane, and Woodace, respectively. Osmocote, Scotts, and Woodace produced 90% of maximum top weight over a wide range of irrigation volumes [≈ 550 ml (0.8 in) to 1200 ml (1.5 in)]. Stomatal conductance of cotoneaster fertilized with Osmocote 24–4–7 increased linearly with increasing volume of irrigation, whereas net photosynthetic rate increased quadratically and was highest at 800 ml (1.1 in). All CRFs, excluding Sustane, had similar dry weights when irrigated with 200 ml (0.3 in). At 800 ml (1.1 in) and 1200 ml (1.7 in), cotoneaster fertilized with Osmocote 24–4–7 and Scotts 23–4–8 produced greater top dry weight compared to Meister, Sustane, and Woodace. Top dry weight of rudbeckia increased quadratically with increasing irrigation volume regardless of CRFs. Maximum dry weight was produced with 1160 ml, 931 ml, 959 ml, 1091 ml, or 1009 ml for plants grown with Meister, Osmocote, Scotts, Sustane, or Woodace, respectively. Ninety percent of the maximum top dry weight of both species within each CRF could be obtained with a 40% reduction in irrigation volume. Nitrogen content of cotoneaster and rudbeckia were unaffected by irrigation volume, whereas P and K content, depending upon CRF and plant, was reduced at low irrigation volumes.


1994 ◽  
Vol 12 (4) ◽  
pp. 181-186
Author(s):  
Melinda C. Shiflett ◽  
Alex X. Niemiera ◽  
Carol E. Leda

Abstract The objective of this study was to determine how a mid-season CRF (controlled release fertilizer) reapplication to container-grown Ilex crenata ‘Helleri’ Thunb. affected growth, substrate solution N content, and the amount on N leached compared to a single early season CRF application (control). ‘Helleri’ holly liners were initially fertilized (March 7) with an 8 to 9 month CRF, Osmocote 18N-2.6P-9.9K (18-6-12), or a 12 to 14 month CRF, Osmocote 17N-3.1P-9.9K (17-7-12). A subset of plants received a CRF reapplication (half rate) of the respective Osmocote formulation on July 19, August 2, or August 16. In addition, 12 plants received a water soluble fertilizer solution (WSF) with each irrigation starting on July 19. All effluent was collected and analyzed for N. Substrate solution N and electrical conductivity (EC) levels (via the pour-through method) and foliar N concentrations were determined every two weeks. Throughout the experiment, plants were irrigated with an irrigation amount that resulted in an ≈ 0.25 leaching fraction (LF). Plant width was determined on November 1. Plant width values were higher for the first and second reapplication and WSF treatments for both formulations than the control. However, in terms of commercial size grades, plants of all treatments were in the same grade. Thus, there was no economic advantage to reapplying CRF. We concluded that CRF reapplication was not necessary when substrate solution N and foliar N values were ≥ 20 mg N/liter and ≥ 2.3%, respectively. Irrigating at a LF of 0.2, the mid-season CRF application increased the amount of N lost from containers by 42% compared to a single, early season CRF application.


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.


HortScience ◽  
2013 ◽  
Vol 48 (1) ◽  
pp. 115-122 ◽  
Author(s):  
Linda L. Taylor ◽  
Alexander X. Niemiera ◽  
Robert D. Wright ◽  
Gregory K. Evanylo ◽  
Wade E. Thomason

Pine tree substrate (PTS), for container plant production, is a relatively new alternative to the commonly used pine bark and peat substrates. Fertility management requires knowledge of nitrogen transformations in this new substrate. The objective of this study was to document the occurrence of nitrification in PTS and to determine if nitrification and density of nitrifying microorganisms are affected by substrate storage time and lime and peat amendments. Pine tree substrate was manufactured by hammermilling chips of ≈15-year-old loblolly pine trees (Pinus taeda L.) through two screen sizes, 4.76 mm (PTS) and 15.9 mm amended with peat (3PTS:1 peat, v:v, PTSP). Pine tree substrate and PTSP were amended with lime at five rates and a peat–perlite mix (4 peat:1 perlite, v:v, PL) served as a control treatment for a total of 11 treatments. Substrates were prepared, placed in plastic storage bags, and stored on shelves in an open shed in Blacksburg, VA. Subsamples were taken at 1, 42, 84, 168, 270, and 365 days after storage. At each subsampling day, each substrate was placed into 12 1-L containers. Six of the 12 were left fallow and six were planted with 14-day-old marigold (Tagetes erecta L. ‘Inca Gold’) seedlings; all containers were placed on a greenhouse bench. Substrates were also collected for most probable number (MPN) assays for nitrifying microorganism quantification. Substrate solution pH, electrical conductivity (EC), ammonium-N (NH4-N), and nitrate-N (NO3-N) were measured on fallow treatments. Marigold substrate solution pH, EC, NH4-N, and NO3-N were measured after 3 weeks of marigold growth. Nitrate-N was detected in fallow containers at low concentrations (0.4 to 5.4 mg·L−1) in PTS in all limed treatments at all subsampling days, but in the non-limed treatment, only at Days 270 and 365. Nitrate-N was detected in the fallow containers at low concentrations (0.7 to 13.7 mg·L−1) in PTSP in the 4- and 6-kg·m−3 lime rates at all subsampling days. Nitrite-oxidizing microorganisms were present in PTS at all subsampling days with the highest numbers measured at Day 1. Ammonium-to-nitrate ratios for the marigold substrate solution extracts for both PTS and PTSP decreased as pH increased. This study shows that nitrifying microorganisms are present and nitrification occurs in PTS and PTSP and is positively correlated to substrate pH.


2011 ◽  
Vol 21 (2) ◽  
pp. 176-180 ◽  
Author(s):  
P. Chris Wilson ◽  
Joseph P. Albano

Nitrate-nitrogen (N) losses in surface drainage and runoff water from ornamental plant production areas can be considerable. In N-limited watersheds, discharge of N from production areas can have negative impacts on nontarget aquatic systems. This study monitored nitrate-N concentrations in production area drainage water originating from a foliage plant production area. Concentrations in drainage water were monitored during the transition from 100% reliance on fertigation using urea and nitrate-based soluble formulations (SF) to a nitrate-based controlled-release formulation (CRF). During the SF use period, nitrate-N concentrations ranged from 0.5 to 322.0 mg·L−1 with a median concentration of 31.2 mg·L−1. Conversely, nitrate-N concentrations during the controlled-release fertilization program ranged from 0 to 147.9 mg·L−1 with a median concentration of 0.9 mg·L−1. This project demonstrates that nitrate-N concentrations in drainage water during the CRF program were reduced by 94% to 97% at the 10th through 95th percentiles relative to the SF fertilization program. Nitrate-N concentrations in drainage water from foliage plant production areas can be reduced by using CRF fertilizer formulations relative to SF formulations/fertigation. Similar results should be expected for other similar containerized crops. Managers located within N-limited watersheds facing N water quality regulations should consider the use of CRF fertilizer formulations as a potential tool (in addition to appropriate application rates and irrigation management) for reducing production impacts on water quality.


2021 ◽  
Vol 20 (6) ◽  
pp. 1503-1514 ◽  
Author(s):  
Qiong WU ◽  
Yu-hui WANG ◽  
Yan-feng DING ◽  
Wei-ke TAO ◽  
Shen GAO ◽  
...  

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