Solid-liquid equilibrium in liquid compound fertilizers

Abstract

concentrations were determined • The solid-liquid equilibrium in the liquid phase after conversion was determined • N content in the liquid phase increased and crystallization temperature decreased with adding of NH 4 NO 3(s) • Basic properties of liquid compound fertilizers were determined • The liquid phase after conversion can be used as a liquid compound fertilizer during the summer Abstract Liquid compound fertilizers (LCF) are aqueous salt solutions which nourish the soil. They contain nitrogen, phosphorus, potassium, sometimes calcium, magnesium and micronutrients. An LCF solution has practically no insoluble residue and contains the elements in a fully digestible form and is a high-speed, highly effective fertilizer. It is important to assess the equilibrium in the solid-liquid system when creating liquid compound fertilizers, since their basic properties, concentration and crystallization temperature, depend on it. The aim of the study was to determine properties of a liquid multicomponent (K + , NH 4 + , Cland PO 4 3-) system. This liquid multicomponent system, which was obtained as a by-product in the conversion of KCl and NH 4 H 2 PO 4 , can be used as a liquid fertilizer. This work investigates liquid fertilizers' chemical composition and their physicochemical properties, such as crystallization temperature, pH, density, viscosity and corrosivity. In order to increase nitrogen concentration, ammonium nitrate was added. Composition of the solid phase obtained by crystallization was identified by methods of chemical and instrumental analysis (radiography, infrared molecular absorption spectroscopy and optical microscopy). The results show that all properties of liquid fertilizers are best when the concentration of NH 4 NO 3 in liquid solutions equals 8%.

Corrosion caused by fertigation with urea and potassium chloride solutions resembles that generated by irrigation

“…Fertigation is an agricultural technique that consists of applying fertilizers diluted in water through the irrigation system itself. However, many fertilizers, when in contact with water or humidity, become highly corrosive, seriously aggravating the corrosion phenomenon (Çetin & Akalp, 2019; Dixon & Liu, 2020; Jancaitiene & Slinksiene, 2018; Rodrigues et al, 2020). Despite this fact, there are practically no studies about the effects of fertigation on corrosion, especially with respect to quantitative aspects, which makes it difficult to understand and estimate the consequences of this phenomenon on irrigation systems.…”