Controlled-release Fertilizer Placement Affects the Leaching Pattern of Nutrients from Nursery Containers during Irrigation

Maximizing nutrient use efficiency while minimizing nutrient leaching and non-point source contributions from containerized crop production systems are goals of researchers and growers. These goals have led to irrigation and crop nutrition management practices that reduce fertilizer and irrigation expenditures and reduce the nutrient load into the environment. However, one area that has received little attention, and may lead to the further refinement of crop management practices, is how dissolved nutrients (solutes) move through a substrate while water is being applied during irrigation. A study was conducted to characterize the effect of a controlled-release fertilizer (CRF) placement method on changes in leachate nutrient concentration throughout an irrigation event and to evaluate these changes at different times throughout a production season. A pine bark:sand (9:1, by volume) substrate was placed in 2.7-L nursery containers (fallow) and was treated with topdressed, incorporated, and dibbled CRF or did not receive CRF. The nutrient leaching pattern was evaluated at 3, 9, and 15 weeks after potting (WAP). Leachate nutrient concentration was the highest in the first 50 mL of effluent and steadily diminished as irrigation continued for the topdressed, incorporated, and the no CRF treatments. Effluent nutrient concentration from containers with dibbled CRF generally increased throughout the first 150 mL of effluent, plateaued briefly, and then diminished. The nutrient load that leached with higher volumes of irrigation water was similar between incorporated and dibbled CRF placements. However, the unique nutrient leaching pattern observed with the dibbled CRF placement method allowed for a lower effluent nutrient load when leaching fractions are low. Dibble may be an advantageous CRF placement method that allows for the conservation of expensive fertilizer resources and mitigates non-point source nutrient contributions by reducing undesired nutrient leaching during irrigation.

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Fertilizer Source and Irrigation Depth Affect Nutrient Leaching During Coleus Container Production

Journal of Environmental Horticulture ◽

10.24266/0738-2898-37.4.113 ◽

2019 ◽

Vol 37 (4) ◽

pp. 113-119

Author(s):

Kayla R. Sanders ◽

Jeffrey S. Beasley ◽

Edward W. Bush ◽

Stacia L. Conger

Keyword(s):

Controlled Release ◽

Best Management Practices ◽

Management Practices ◽

Nutrient Leaching ◽

Water Soluble ◽

Inorganic N ◽

Controlled Release Fertilizer ◽

Best Management ◽

Soluble Fertilizer ◽

Container Production

Abstract Nutrient leaching during nursery container production can have negative effects on plant growth and the environment. The objective of this study was to evaluate effects of fertilizer source at two irrigation depths on nutrient leaching during coleus [Plectranthus scutellarioides (L.) Codd] ‘Solar Sunrise' container production to develop best management practices. Coleus received no fertilizer, a controlled-release fertilizer (CRF), or a water-soluble fertilizer (WSF) applied at 0.30 kg N and P per m3 (0.02 lb per ft3) and were irrigated at 1.9 or 3.8 cm.day−1 (0.7 or 1.5 in.day−1) for 56 days after planting (DAP). Leachate was analyzed every 7 DAP for inorganic N and dissolved total P (DTP). At 56 DAP, root biomass, leaf quality, and plant growth index were similar between CRF and WSF treatments at both irrigation depths. Highest inorganic N and DTP losses occurred within 21 DAP. Application of WSF resulted in higher cumulative N and DTP losses compared to CRF applications. Coleus irrigated at 3.8 cm.day−1 and fertilized with WSF resulted in higher DTP losses compared to CRF applications regardless of irrigation depth. Reducing irrigation reduced inorganic N leaching for each fertilizer source. Application of CRF provided consistent growth while curbing nutrient losses across both irrigation depths compared to WSF. Index words: controlled-release fertilizer, water-soluble fertilizer, nursery producers, best management practices. Chemicals used in this study: Micronutrients mix (Micromax®); controlled-release fertilizer (Osmocote® Classic); water-soluble fertilizer (Grower's Special). Species used in this study: Coleus [Plectranthus scutellarioides (L.) Codd] ‘Solar Sunrise'.

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FATE AND MOVEMENT OF NO3– N AS A RESULT OF STAGED LEACHING IRRIGATION EVENTS AND FERTILIZER SOURCE DURING POTATO PRODUCTION IN NORTHEAST FLORIDA

HortScience ◽

10.21273/hortsci.41.3.498b ◽

2006 ◽

Vol 41 (3) ◽

pp. 498B-498

Author(s):

Christine M. Worthington ◽

Chad M. Hutchinson

Keyword(s):

Controlled Release ◽

Best Management Practices ◽

Management Practices ◽

Potato Crop ◽

Potato Production ◽

Water Runoff ◽

Controlled Release Fertilizer ◽

Run Off ◽

N Loading ◽

Surface Water Runoff

The St. Johns River has been identified by the state of Florida as a priority water body in need of restoration. Best Management Practices were evaluated for potato (Solanum tuberosum L. `Atlantic') production in the Tri-County Agricultural Area to reduce nitrate run-off from about 9,300 ha in production. Objectives of this study were 1) determine the influence of soluble and controlled release fertilizer (CRF) and timing of leaching irrigation on nitrate leaching and 2) compare yield and quality of the potato crop fertilized with either a soluble or controlled release nitrogen fertilizer in a seepage irrigated production system. The experiment was a split-split plot with four replications. Main plots were irrigation events (0, 2, 4, 8, and 12 weeks after planting, (WAP)), nitrogen source and rates included (ammonium nitrate (AN) 224 kg·ha–1 or controlled release fertilizer (CRF) 196 kg·ha–1). About 7.6 cm of water was applied at each irrigation event and surface water runoff collected. CRF decreased NO3-N loading by an average of 35%, 28%, and 32% compared to AN fertilizer during the 2, 8, and 12 WAP irrigation events, respectively, compared to AN. Plants in CRF treatments had significantly higher total and marketable tuber yields (30 and 25 t·ha–1) compared to plants in AN treatments (27 and 23 t·ha–1), respectively. Plants in the CRF treatments also had significantly higher total and marketable yields in 2005 (28 and 23 t·ha–1) compared to plants in AN treatments (25 and 21 t·ha–1), respectively. CRF was an effective alternative to conventional soluble forms of fertilizer maintaining yields and protecting natural resources from nonpoint source pollution.

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BMP Assessments Using CCROP (Container Crop Resource Optimization Program) Simulation Tools

Journal of Environmental Horticulture ◽

10.24266/0738-2898.30.2.102 ◽

2012 ◽

Vol 30 (2) ◽

pp. 102-109

Author(s):

Jeff B. Million ◽

Thomas H. Yeager

Keyword(s):

Controlled Release ◽

Best Management Practices ◽

Management Practices ◽

Planting Date ◽

Resource Optimization ◽

Weather Data ◽

Fertilizer N ◽

Controlled Release Fertilizer ◽

Optimization Program ◽

Simulation Tools

We describe and demonstrate the use of web-based simulation tools that use the plant growth model CCROP (Container Crop Resource Optimization Program) to quantify the expected impacts that two example best management practices (BMP) would have on water and N use during production of a container-grown woody ornamental plant. For Example 1, an irrigation BMP of applying amounts of water proportional to plant demand (evapotranspiration) was compared to fixed irrigation rates of 1.0 and 1.5 cm·d−1 at two locations in Florida and for six planting dates. For Example 2, a fertilizer BMP of customizing controlled-release fertilizer N rates based on expected N response was compared to a single N rate that resulted in optimal growth for six plant dates. Simulations based on eight years of historical weather data projected that the irrigation BMP would reduce water usage 24–57% with greater savings coinciding with longer crop times as affected by planting date and location. Similarly, simulations projected that the fertilizer BMP would reduce controlled-release fertilizer N applied 15–37% depending upon container size and planting date. Simulation tools also estimated cost savings and reduced environmental impact (N leaching loss) resulting from BMPs. We concluded that CCROP simulation tools can help growers and grower-advisers quantify potential impacts so that informed, economic decisions regarding BMP implementation can be made which are applicable to management practices and weather at the container nursery.

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