Reducing Ammonia Volatilization and Improving Nitrogen use Efficiency of Rice at Different Depths of Urea Supergranule Application

ABSTRACT

An experiment was conducted to determine the depth of urea supergranule (USG) application that reduces ammonia (NH₃) volatilization and improves nitrogen use efficiency of rice. Canne, Voudou, Akuse, and Bumbi series were used. Treatments involved surface application of prilled urea (PU), USG applied at 0, 4, 8, 12 and 16 cm depths and a control. Rice variety IR-841 was grown up to maturity. Closed chamber device was used to trap NH₃. Results indicated that the highest mean NH₃ loss occurred in Bumbi series (13.67%) while the lowest was Canne series (8.16%). USG applied at 0 cm resulted in the highest NH₃ loss (37.2%). NH₃ volatilization decreased with increasing depth of USG application. The highest grain yields were obtained when USG was applied at 4 and 8 cm. In Canne series, the highest agronomic use efficiency (AE) of N (57 g g⁻¹) was obtained with USG applied either at 8 or 12 cm while the highest recovery efficiency (RE) (84%) occurred at 8 cm. In Akuse series, the highest AE (55 g g⁻¹) and RE (78%) were obtained when USG was placed at 8 cm. In Voudou and Bumbi series, the highest AE (45 and 48 g g⁻¹ respectively) and RE (64%) were obtained with USG deep placed at 4 cm. The results therefore suggested different specific depths of USG application to reduce ammonia loss and improve nitrogen use efficiency.

KEYWORDS:

• Application depth
• ammonia volatilization
• nitrogen use efficiency and USG

Acknowledgments

The authors wish to thank the West Africa Agricultural Productivity Program of Togo (WAAPP-Togo) and the Institute of Agricultural Research of Togo (ITRA) for financing this study.

Additional information

Notes on contributors

Kossi Koudjega

Kossi Koudjega is a PhD candidate of Department of Soil Science, University of Ghana. Researching on nitrogen loss in rice fields.

Komlan Adigninou Ablede

Komlan A. Ablede ia a PhD candidate of Department of Soil Science, University of Ghana. Researching on nutrient management in rice.

Innocent Yao Dotse Lawson

Innocent Y. D. Lawson is a senior lecturer in the Department of Soil Science. Area of specialization is Soil Microbiology and Fertility. Current research on nitrogen leaching in the soil.

Mark Kofi Abekoe

Mark K. Abekoe is an Associate Professor in the Department of Soil Science in the area of Soil Chemistry and Fertility.

Emmanuel Owusu-Bennoah

Emmanuel Owusu-Bennoah is an Associate Professor in the Department of Soil Science in the area of Soil Chemistry and Fertility.

Daniel Kekeli Tsatsu

Daniel K. Tsatsu is a senior technician in the Department of Soil Science who assists in research activities.