|NACKLEY, LLOYD - Oregon State University|
|MCCAULEY, DALYN - Oregon State University|
Submitted to: HortTechnology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 8/11/2023
Publication Date: 10/24/2023
Citation: Nackley, L., Mccauley, D., Scagel, C.F. 2023. Hot mess: heatwaves effect on control release fertilizer longevity. HortTechnology. Volume 58, Issue 11, Pages 1459-1460. https://doi.org/10.21273/HORTSCI17325-23.
Interpretive Summary: Control release fertilizers (CRF) are fertilizers used in the production of both container grown and field nursery crops. Fertilizer release determined by manufacturers do not correlate well with release in production situations because of daily and seasonal environmental fluctuation. CRF materials may become less predictable given the temperature variability associated with climate change. We documented CRF release during a recent unprecedented early season heat wave in Oregon. Our results highlight the impact that heatwaves can have on nutrient delivery by CRF and indicate that adaptation strategies for fertilizer management may be necessary given the likelihood that extreme temperatures will continue to impact horticultural production systems for years to come.
Technical Abstract: Control release fertilizers (CRF) are fertilizers that are delivered in a pellet form and the release rates are controlled by temperature. An experiment was carried out at the North Willamette Research and Extension Center located in Aurora, Oregon (GPS Coordinates: 45°16’51” N—122°45’04” W) with six fertilizer concentrations. The Polyon CRF fertilizer used had 20% nitrogen, 1.3% phosphorus, 7.47% potassium and minor elements and was designed to last 6-7 months at 70°F. During the experiment, the Pacific Northwest experienced a series of early summer (June) heatwaves, including the hottest temperatures recorded for the region. The heatwaves caused an earlier release of the CRF, leading to high levels of nitrogen (NO3 and NH4) leaching in the 100% and 80% fertilizer concentration groups. This leaching caused a loss of materials and nitrogen enrichment in the nursery runoff and drainage water, which can harm the drainage infrastructure and nearby aquatic environments. The sudden changes in temperature disrupted the release of CRF and the plants' demand for nutrients. Extreme weather adaptation strategies are necessary to sustain horticultural production in a period with increased temperature volatility.