A) Enhancing urea-nitrogen use efficiency and rice yield using rejected sago (MetroxylonsaguRottb) starch

Introduction:

Urea is one of the fundamental N fertilizers required for crop production and global food security. To achieve high yield of crops,excessive use of urea does not only cause low urea-N use efficiency and economically loss, but it also contributes to environmentalpollution. One of the promising alternatives to increase urea-N use efficiency, improve soil N availability, and lessen potentialenvironmental effects from excessive use of urea is to coaturea with rejected sago starch.

Coated urea minimizes losses of urea-N through ammonia volatilization and nitrate leaching. There is lack of information on the useof rejected sago starch to enhance urea-N use efficiencyvia coating urea with this material. The objectives of this study are todetermine: (i) selected physico-chemical properties of rejected sago starch as urea coating material, (ii) optimum rate of starchcoated urea to improve N availability, N use efficiency, and grain yield of an indigenous Sarawak paddy (padipaya), and (ii)economic viability of enhancing urea-N release using rejected sago starch. The justification of using rejected sago starch as a coatingmaterial for urea is because of its availability, acidulating property, andbiodegradability. The acidic nature of rejected sago starch could mitigate N loss via ammonia volatilization during urea hydrolysis. Rapid urea hydrolysis causes soil pH at the application site to increase result in N volatilized in the form of ammonia. The magnitudeof ammonia volatilization could be minimize using rejected sago starch by temporarily acidify soil microsite to reduce concentrationof ammonia. Starch coated urea could ensure that N will be released slowly to improve N availability, N use efficiency, and rice yield. It is expected that urea coated with rejected sago starch could improve rice yield with prolonged N availability and minimal use ofurea-N fertilization compare with conventional urea.

For more further enquiries:

Prof. Dr. Ahmed Osumanu Haruna
Professor
Department of Crop Science
Faculty of Agricultural Science and Forestry
Tel: +6086 855406
Email: osumanu@upm.edu.my

Updated:: 21/08/2020 [lanz]