Review on materials & methods to produce controlled release coated urea fertilizer

Abstract ; With the exponential growth of the global population, the agricultural sector is bound to use ever larger quantities of fertilizers to augment the food supply, which consequently increases food production costs. Urea, when applied to crops is vulnerable to losses from volatilization and leaching. Current methods also reduce nitrogen use ef ciency (NUE) by plants which limits crop yields and, moreover, contributes towards environmental pollution in terms of hazardous gaseous emissions and water eutrophication. An approach that offsets this pollution while also enhancing NUE is the use of controlled release urea (CRU) for which several methods and materials have been reported. The physical intromission of urea granules in an appropriate coating material is one such technique that produces controlled release coated urea (CRCU). The development of CRCU is a green technology that not only reduces nitrogen loss caused by volatilization and leaching, but also alters the kinetics of nitrogen release, which, in turn, provides nutrients to plants at a pace that is more compatible with their metabolic needs. This review covers the research quantum regarding the physical coating of original urea granules. Special emphasis is placed on the latest coating methods as well as release experiments and mechanisms with an integrated critical analyses followed by suggestions for future research . Source : Journal of Controlled Release 181 (2014) 11 …21

A simple and robust method for determination of neem (Azadirachta indica A. Juss) oil in neem oil coated urea

Abstract: The production of neem oil coated urea (NOCU), a technology developed by the Indian Agricultural Research Institute, has been grown to over 2.0 million tons per year. The estimation of neem oil content in NOCU is important due to its significance in ensuring agronomic efficiency. Therefore, this study was taken up to develop a simple method for the determination of neem oil in NOCU. The procedure involves extraction of neem oil from NOCU; saponification of extracted oil; oxidation of released glycerol to formaldehyde, and subsequent conversion of formaldehyde to a dihydrolutidine derivative. Its concentration was determined spectrophotometrically. The recoveries of neem oil from NOCU with oil load of 500 and 1000 ppm were 87.6 ± 3.0% and 90.0 ± 4.8% respectively with direct method; and improved to 92.6 ± 4.0% and 96.7 ± 3.8% after including the in situ purification. A simple method based on the Hantzsch reaction was developed for the determination of neem oil in NOCU. This method is superior to earlier methods in terms of sensitivity, simplicity, and time required. Source : Journal Toxicological & Environmental Chemistry ,Volume 94, 2012 - Issue 4

Review on materials & methods to produce controlled release coated urea fertilizer

Abstract ; With the exponential growth of the global population, the agricultural sector is bound to use ever larger quantities of fertilizers to augment the food supply, which consequently increases food production costs. Urea, when applied to crops is vulnerable to losses from volatilization and leaching. Current methods also reduce nitrogen use ef ciency (NUE) by plants which limits crop yields and, moreover, contributes towards environmental pollution in terms of hazardous gaseous emissions and water eutrophication. An approach that offsets this pollution while also enhancing NUE is the use of controlled release urea (CRU) for which several methods and materials have been reported. The physical intromission of urea granules in an appropriate coating material is one such technique that produces controlled release coated urea (CRCU). The development of CRCU is a green technology that not only reduces nitrogen loss caused by volatilization and leaching, but also alters the kinetics of nitrogen release, which, in turn, provides nutrients to plants at a pace that is more compatible with their metabolic needs. This review covers the research quantum regarding the physical coating of original urea granules. Special emphasis is placed on the latest coating methods as well as release experiments and mechanisms with an integrated critical analyses followed by suggestions for future research . Source : Journal of Controlled Release 181 (2014) 11 …21

A simple and robust method for determination of neem (Azadirachta indica A. Juss) oil in neem oil coated urea

Abstract: The production of neem oil coated urea (NOCU), a technology developed by the Indian Agricultural Research Institute, has been grown to over 2.0 million tons per year. The estimation of neem oil content in NOCU is important due to its significance in ensuring agronomic efficiency. Therefore, this study was taken up to develop a simple method for the determination of neem oil in NOCU. The procedure involves extraction of neem oil from NOCU; saponification of extracted oil; oxidation of released glycerol to formaldehyde, and subsequent conversion of formaldehyde to a dihydrolutidine derivative. Its concentration was determined spectrophotometrically. The recoveries of neem oil from NOCU with oil load of 500 and 1000 ppm were 87.6 ± 3.0% and 90.0 ± 4.8% respectively with direct method; and improved to 92.6 ± 4.0% and 96.7 ± 3.8% after including the in situ purification. A simple method based on the Hantzsch reaction was developed for the determination of neem oil in NOCU. This method is superior to earlier methods in terms of sensitivity, simplicity, and time required. Source : Journal Toxicological & Environmental Chemistry ,Volume 94, 2012 - Issue 4

Dear Allah Nawaz,

Please follow the below given link and PDF attachments.

https://www.academia.edu/19741151/NEEM_COATED_UREA_AN_ECO-FRIENDLY_APPROACHES

Good luck

It may retard ammonia volatilisation to limited extent and keep microbes to away for short period. Also act as nitrification inhibitor.

I am of the opinion that neem oil coated urea will improve the nitrogen use efficiency by acting as urease as well as nitrification inhibitor. Because the oil emulsion coating on urea will slow down its hydrolysis being hydrophobic and hence nitrification inhibition by lowering the population of nitrifying bacteria in soil.