M. Sc. Dissertation
Rice yields in developing countries in general and specifically in Tanzania remain low
due to limited adoption of new innovations by smallholder rice farmers. The System of
Rice Intensification (SRI) is believed to have promising potential for increasing rice
yields. However, the factors influencing the adoption decisions as well as adoption
impacts have been a subject of debate. This study was conducted to analyse the adoption
of SRI and its impact on rice yields in Mbarali District. Specifically, the study focused on
determining the extent of SRI components adoption by smallholder rice farmers,
analysing the factors affecting SRI components adoption decisions and determining the
impacts of adopted SRI component combinations on rice yields. Data were collected from
three irrigation schemes involving 318 smallholder rice farmers. The extent of SRI
components adoption was estimated as a percentage of area under rice production
allocated to SRI by smallholder rice farmer. Multinomial endogenous treatment effect
model was used to analyse the determinants of SRI component combinations adoption
and the impact of the adopted packages on rice yields. The study findings indicate that on
average SRI adopters allocate about 73% of rice cultivated land on SRI. The likelihood
of smallholder rice farmers adopting SRI component combinations is significantly
determined by education level of the household heard, active family labour force size,
experience in rice production, access to off farm activities, farm size, farm level status,
adequate availability of water for irrigation, access to credit facilities and information
from formal sources. Furthermore, the results reveal that all SRI component combinations
have a positive and significant impact on yields although on their impact differ in
magnitude. The highest rice yields (41%) are obtained when the full package comprising
all components (plant, soil and water management) is adopted, hence future interventions
with comprehensive SRI package are recommended.