Title
Synthesis of cellulose-based hydrogel for regulating the release of nitrogen fertilizer
Authors
MOUROUG THAHER ZYADEH, IMAD MOHD KHAIR HAMADNEH, MAHMOUD ABDEL-RAHMAN KASRAWI, HAYTHEM SAADEH and MOHAMMED HASAN SHAHEIN

Received August 1, 2022
Published Volume 57 Issue 1-2 January-February
Keywords citric acid, slow-release fertilizer, potassium nitrate, ammonium sulfate, soil-water retention, CMC-Na

Abstract
This study aimed to synthesize a cellulose-based hydrogel as a new green fertilizer with slow-release properties. The cellulose-based hydrogel was prepared by reacting carboxymethyl cellulose solution with cellulose and was cross linked with citric acid. The structure of the hydrogel was confirmed by FT-IR. The nitrogen fertilizers KNO3 and (NH4)2SO4 were loaded during the preparation. The swelling behavior of the hydrogel in deionized water was studied, in addition to the effects of pH, salinity, and drought on swelling behavior. Finally, the fertilizer release behavior in deionized water and a soil mix was investigated, in addition to the soil water content. The optimum hydrogel formulation (HG) showed good absorbance capacity – of 450%, and good durability for one month in deionized water. The swelling-deswelling studies revealed its sensitivity to different solutions. The HG loaded with nitrogen fertilizers showed slow, sustained release rates in deionized water and the soil mix; the cumulative release rates approached 70%, 65%, 60%, and 65%, respectively. Moreover, soil moisture was improved by the addition of the hydrogel by 100% on day 20 and reached 12% on day 30. The results were in accordance with the Committee of European Normalization standards. In conclusion, this new green hydrogel could be used in agricultural applications.