Research Reports

Study of Organic and Inorganic Nutrient Input Options for Wet-season Lowland Rice Cropping on the Attapeu Plain in Southern Lao PDR

The field experiment which was undertaken in the 2011 and 2012 wet-seasons, this study was aimed at assessing appropriate fertilizer management (rates and type) for improving lowland rice production on the Attapeu Plain in Thahin, Lagnaonua and Konghang villages, Samakisay district, Attapeu province. The selection of this locality was based on the very poor soils that prevail in the area (with particularly low levels of P and K). Manure based organic fertilizer treatments (zero, 5 and 10 t ha-1) were evaluated in combination with N application rates ranging from 60 to 120 kg ha-1. The N was applied in combination with basal applications of 30 kg ha-1 of P2O5 and 20 kg ha-1 K2O). The rice variety used in the study was the recently released improved drought tolerant variety TDK11. The results of field experiment in 2011 and 2012 wet seasons was no significant difference in grain yield responses to the two rates of organic fertilizer application (5 t/ha and 10 t/ha of manure) when combined with the application of chemical fertilizer indicated that there were not significant different among 5 t/ha and 10 t/ha of manure mixed with different chemical fertilizer rates. The application of 5 t/ha of manure when mixed with chemical fertilizer at the rate of 60-30-20 kg/ha of (N- P2O5 and K2O), gave a yield of 4.3 t/ha. Increasing the rice grain yield up to the government’s target objective of between 4 - 5 t/ha on the sandy soils of low soil fertility on the Attapeu plain, there are 2 options. One option is the application chemical fertilizer at the rates of 120-30-20 kg/ha of (N- P2O5 and K2O), or the application of cattle manure at 5 t/ha, mixed with 60-30-20 kg/ha of (N- P2O5 and K2O). The combination of the cattle manure and the chemical fertilizer can potentially reduce the rate of application of ureaby up to 50% when compared with the use of chemical fertilizer alone.


Khonepany Dounphady, Nivong sipaseuth, Pheng Sengxua and Souliyan Phommavongsa