Impact of Improved Rice Variety on Productivity and Crop Diversity: A Case of Singye Gewog (Block) in Sarpang District of Southern Bhutan

Main Article Content

Chezang Dendup
Sonam Dorji
Sonam Tshomo
Langa Tshering


The survey was conducted in 2019 to generate baseline information for rice yield and varietal diversity, involving 54 experienced rice farmers of Singye Gewog (block) under Sarpang Dzongkhag (district) in Southern Bhutan. A total of 9 varieties were found under cultivation, of which 2 and 7 were assessed to be improved varieties and landraces respectively. The mean yield of improved varieties was 1253.2 kg acre-1, whereas landraces yielded 777.1 kg acre-1 (P=.006). The chronological varietal diversity revealed that 47.05% of farmer-named varieties were either lost or replaced over 20 years. However, landrace such as Choti Mahsino was popular, covering 24.6% of the rice cultivated area. Further, taste, yield stability, and utility for festivals were the main reasons for perpetuating landraces’ cultivation. The study showed the positive impact of improved varieties on productivity while it has narrowed varietal diversity. On the flip side, the current research found that only one improved variety was adopted which shows a need to promote improved varieties, while the improvement of landraces should also be given priority.

Variety adoption, diversity, rice yield, landraces, improved varieties.

Article Details

How to Cite
Dendup, C., Dorji, S., Tshomo, S., & Tshering, L. (2021). Impact of Improved Rice Variety on Productivity and Crop Diversity: A Case of Singye Gewog (Block) in Sarpang District of Southern Bhutan. Asian Journal of Agricultural Extension, Economics & Sociology, 39(1), 96-104.
Original Research Article


International Rice Research Institute. Annual report. Race for Impact. Los Baños, Philippines; 2019.

Department of Agriculture. RNR census report 2019. Ministry of Agriculture and Forests. Thimphu, Bhutan; 2019.

Department of Revenue & Customs. Bhutan trade statistics. Ministry of Finance. Thimphu, Bhutan; 2019.

Department of Agriculture. Inventory of released and de-notified crops in Bhutan (1988—2020). Ministry of Agriculture and Forests. Thimphu, Bhutan; 2020.

Shrestra S. An economic assessment of the rice research program in Bhutan. Los Baños, Philippines. International Rice Research Intitute. Los Baños, Philippines; 2004.

Ghimiray M, Pandey S, Velasco LM. Bhutan report on rice. Country report for the project Tracking of Improved Varieties in South Asia. IRRI monograph. Internation Rice Research Institute. Los Baños, Philippines; 2013.

Chhogyel N, Bajgai Y. Modern rice varieties adoption to raise productivity: A case study of two districts in Bhutan. SAARC Journal of Agriculture. 2015;13(2):34—49.

Nguezet PMD, Diagne A, Okoruwa VO, Ojehomon V. Impact of improved rice technology (NERICA varieties) on income and poverty among rice farming households in Nigeria: A local average treatment effect (LATE) approach. Quarterly Journal of International Agriculture. 2011;50(3):267—291.

Bannor RK, Kumar GAK, Kyeremeh HO, Wongnaa CA. Adoption and impact of modern rice varieties on poverty in Eastern India. Rice Science. 2020;27(1):56—66.

Tsinigo E, Yankyerah KO, Fialor SC. Impact of improved rice variety on productivity among smallholder farmers in Ghana. Turkish journal of Agriculture, Food Science and Technology. 2017;5(2): 164—169.

Witcombe JR, Khadka K, Puri RR, Khanal NP, Sapkota A, Joshi KD. Adoption of rice varieties- i. age of varieties and pattern of variability. Expl. Agric. Cambridge University. 2016;1—16.

Chaudhary P, Gauchan D, Rana D, Sthapit BR. Potential loss of rice landraces from a Terai community in Nepal: A case study from Kachora, Bara. Plant Genetic Resources. 2004;137:1—8.

Tiongco M, Hossain M. Adoption of modern varieties and rice varietal diversity on household farms in Bangladesh. HarvestPlus Working Paper 22. Washington, D.C: International Food Policy Research Institute (IFPRI); 2015.

Barry MB, Diagne A, Sogbossi MJ, Pham JL, Diwara S, Ahmadi N. Recent changes in varietal diversity of rice in Guinea. Plant Genetic Resources: Characterization and Utilization. 2008;1—9.

Steele KA, Gyawali S, Joshi KD, Shrestha P, Sthapit BR, Witcombe JR. Has the introduction of modern rice varieties changed ricegenetic diversity in a high-altitude region of Nepal? Field Crops Res; 2009.
DOI: 10.1016/j.fcr.2009.04.002

Chhogyel N, Kumar L, Bajgai Y, Jayasinghe LS. Prediction of Bhutan’s ecological distribution of rice (Oryza sativa L.) under the impact of climate change through maximum entropy modeling. Cambridge University Press. 2020;158(1—2):25—37.

Katwal TB, Dorji S, Dorji R, Tshering L, Ghimiray M, Chetteri GB, et al. Community perspectives on the on-farm diversity of six major cereals and climate Change in Bhutan. Agriculture. 2015;5:2—16.

Wang Y, Wang Y, Sun X, Caiji Z, Yang J, Cui D, et al. Influence of ethnic traditional cultures on genetic diversity of rice landraces under on-farm conservation in south-west China. Journal of of Ethnobiology and Ethnomedicine. 2016;12:51.
DOI: 10.1186/s13002-016-0120-0

Zhu Y, Wang Y, Chen H, Lu BR. Conserving traditional rice varieties through management for crop diversity. BioScience. 2003;53(2):158—162.

Dendup C, Chhogyel N, Ngawang. Effects of different planting methods on rice (Oryza sativa L.) crop performance and cost of production. Bhutanese Journal of Agrculture. 2018;1(1):13—22.

Samal P, Pandey S, Kumar GAK, Barah BC. Rice ecosystems & factors affecting varietal adoption in rainfed coastal Orissa: A multivariate probit analysis. Agricultural Economics Research Review. 2011;24:161—167.

Thant AA, Teutscherova N, Vazquez E, Kalousova M, Phyo A, Singh RK, et al. On-farm rice diversity and farmers’ preferences for varietal attributes in Ayeyarwady Delta, Myanmar. Journal of Crop Improvement. 2020;34(4):549—570.
DOI: 10.1080/15427528.2020.11746457

Bello LO, Baiyegunhi LJS, Abbeam GD. Productivity impact of improved rice varieties’ adoption: Case o smalljolder rice farmers in Nigeria. Economics of Innovation and New Technology; 2020.
DOI: 10.1080/10435599.2020.1776488

Hossain M, Bose ML, Mustafi BAA. Adoption and productivity impact of modern rice varieties in Bangladesh. The Developing Economies. 2006;44(2): 149—166.

Department of Agriculture. Agriculture Statistics 2010. Ministry of agriculture and forests. Thimphu, Bhutan; 2010.

Rana RB, Garforth C, Sthapit BR. Farmers’ management of rice varietal diversity in mid-hills of Nepal: Implications for on-farm conservation and crop improvement. Plant Genetic Resources: Characterization and Utilization. 2008;1—13.
DOI: 10.1017/31479262108048259

Gauchan D, Joshi BK, Sthapit S, Jarvis D. Traditional crops for household food security and factors associated with on-farm diversity in the mountains of Nepal. The journal of Agriculture and Environment. 2020;21:31—43.

Joshi GR, Bauer S. Determinants of rice variety diversity on household farms in the Terai region of Nepal. Contributed paper prepared for presentation at the International Association of Agricultural Economists Conference, Gold Coast, August 12th -18th; 2006.

Nujten E, Almekinders JM. Mechanisms explaining variety naming by farmers and name consistency of rice varieties in The Gambia. Economic Botany. 2008;62(2):148—168.

Pant KP. More profitable rice varieties crowd beneficial landraces out. The journal of Agriculture and Environment. 2010;11:1—9.