Influence of Diurnal Temperature on Nutrient Release Patterns of Three Polymer-coated Fertilizers

Abstract

<jats:p>This study was conducted to determine the effects of temperature on nutrient release patterns of three polymer-coated fertilizers (PCFs), each using a different coating technology: Osmocote Plus 15N-3.93P-9.96K, Polyon 18N-2.62P-9.96K, and Nutricote 18N-2.62P-6.64K. Each fertilizer was placed in a sand-filled column and leached with distilled water at ≈100 mL·h<jats:sup>-1</jats:sup>, while being subjected to a simulated diurnal container temperature change from 20 to 40 °C and back to 20 °C over a period of 20 hours. Column leachate was collected hourly and measured for soluble salts and NO<jats:sub>3</jats:sub>-N and NH<jats:sub>4</jats:sub>-N content. For all fertilizers, nutrient release increased and decreased with the respective increase and decrease in temperature. Nutrient release patterns of the three fertilizers differed, with Osmocote Plus showing the greatest overall change in nutrient release between 20 and 40 °C, and Nutricote the least.</jats:p>

Application of controlled nutrient release to permeable reactive barriers

“…is consistent with previous findings (Husby, 2000;Jacobs, 2005;Adams et al, 2013). For example, Adams et al (2013) found that total NH 3 and NO 3 À were >70% expended while PO 4 3À was <60% expended after 9 months.…”

“…An increase in temperature commonly results in increased nutrient release from polymer-coated fertilisers (Husby, 2000;Jacobs, 2005;Du et al, 2006;Adams et al, 2013). In this study and others, Polyon™ clearly demonstrates faster release of NePeK at 23 C compared to 4 C (Adams et al, 2013).…”

Macro‐ and micronutrient‐release characteristics of three polymer‐coated fertilizers: Theory and measurements

“…However, there is no consensus on the effect of temperature on PCF collectively or on individual PCF technologies in the recent literature. Husby et al (2003) claimed that the effect of a diurnal temperature fluctuation on nutrient-release rate was a sensational 63.9% to 206.2% per°C (1278% to 4124% in total), depending on the PCF (Osmocote, Nutricote, and Polyon) when temperature was varied between 20°C and 40°C. Husby et al (2003) reported that Osmocote was the most sensitive to temperature of the three technologies.…”

“…Husby et al (2003) claimed that the effect of a diurnal temperature fluctuation on nutrient-release rate was a sensational 63.9% to 206.2% per°C (1278% to 4124% in total), depending on the PCF (Osmocote, Nutricote, and Polyon) when temperature was varied between 20°C and 40°C. Husby et al (2003) reported that Osmocote was the most sensitive to temperature of the three technologies. Cabrera (1997) reported significant increases in N leaching as media temperature increased in pots of media containing Prokote ® , a Polyon, and two Osmocote fertilizers (High Nitrogen and Fast Start).…”

A column perfusion test to assess the kinetics of nutrient release by soluble, sparingly soluble and coated granular fertilizers

“…A laboratory method is crucial to quantify differences between commonly used fertilizers and slow release ones under controlled conditions to provide an understanding of the mode of action of the release at varying stages of development. In recent years, for example, with polymer chemistry advancements, several polymer coated fertilizers have been produced, the nutrient release curves for which vary with temperature and time ( Husby , ). Trenkel () pointed out that some have been developed with a parabolic, sigmoidal or linear nutrient release, with the latter two shown to better match plant demand.…”