Formulation and Controlled Release behavior of Urea Fertilizer from biodegradable superabsorbent composite

El‐Refaie Kenawy ,Mohamed Rashad ,Ali Hosny

doi:10.21608/djs.2018.138903

Abstract

Controlled release technology is one of the most efficient techniques to reduce environmental hazards accompanied with fertilizers and herbicides. In the present work, new formulations for controlled release of urea fertilizers were prepared based on biodegradable polymers and agricultural waste. The release behavior of urea fertilizer from the superabsorbent composite was estimated using UV/Vis spectrophotometer. The effect of the pH of the soil on the release rate was also investigated.

Highlights

Urea is the most widely used fertilizer globally due to its high nitrogen content (46%), low cost, and ease of application [1],[2]
To prepare the controlled release urea fertilizer (CRUF), a series of samples was prepared according to the following procedure: a weighted quantity of the superabsorbent composite was mixed with a weighted quantity of urea dissolved in distilled water for 24 hours to allow it reaching swelling equilibrium
The studies were carried out for 16 hours the results showed clearly that on increasing the amount of composite in the formulation from 10 wt% to 50 wt%, the release rate decrease and release time increased from 3 hours to 16 hours

Summary

Introduction

Urea is the most widely used fertilizer globally due to its high nitrogen content (46%), low cost, and ease of application [1],[2]. The development of controlled release coated urea (CRCU) has been a subject of interest for decades [3]. Plants need only a small quantity of food, so excess nutrients are lost due to leaching. An ideal controlled release fertilizer is coated with a natural or semi-natural, environmentally friendly macromolecule material that retards fertilizer release to such a slow pace that a single application to the soil can meet nutrient requirements for model crop growth [5]. The. terms, controlled release fertilizer (CRF), and slow release fertilizer (SRF), are generally considered analogous. In the case of SRFs, the pattern of nutrient release is nearly unpredictable and remains subject to changes in soil type and climatic conditions. New controlled release urea fertilizer was prepared using biodegradable superabsorbent composite

Preparation of the controlled release urea fertilizer

Study of urea release from the CRUF matrix in water

Release of urea from CRUF in soil

Results and discussions

Conclusion