Thesis
Although Climate Smart Agriculture Practises (CSA-practises) have been promoted and
implemented in the Tanzania, but usage of CSA-practises is still low while their impact on
food security is not well documented, especially when used in combinations. This study
examined the usage of different CSA-practises and their impact on food security among
farming households in Mbeya and Songwe Regions in Tanzania with specific objectives to; a)
assess the usage and intensity of using multiple CSA-Practises by farming households b)
assess the determinants of using combinations of CSA-Practises by farming households c)
evaluate the impact of using combination of crop rotation, residue retention and intercropping
on food security d) evaluate the impact of using combination of organic manure, irrigation
and drought tolerant maize seeds on food security and e) evaluate the impact of climate-smart
irrigation practise on food security.
Multistage sampling technique was employed in sampling 1443 farming households. A
household survey was conducted whereby the primary data were collected using a structured
questionnaire. The Household Dietary Diversity Score per Adult Equivalent Unit
(HDDS/AEU) and Food Variety Score per Adult Equivalent Unit (FVS/AEU) were used as
indicators to measure household food security.
To assess the usage of the multiple CSA-practises a multivariate probit model was used while
the ordered probit model was used to examine the intensity of using CSA-practises. A
multinomial probit model was employed to estimate the factors influencing the use of
combinations of CSA-practises (i.e. crop-rotation, crop residue retention and intercropping).
To examine the impact of using a combination of CSA-practises (crop rotation, residue
retention and intercropping), a multinomial endogenous switching regression model was
employed. Furthermore, the study employed a multinomial endogenous treatment effect
regression model to evaluated the impact of using organic manure, drought-tolerant maize
seeds. and irrigation on food security. Furthermore, endogenous switching regression model
was employed to evaluate the impact of using climate smart irrigation on food security. The
evaluation methods used in this study are appropriate in the analysis of the control for both
observed and unobserved heterogeneity. Other evaluation approaches such as propensity
score matching and inversely probability-weighted regression (IPWR) can only control
observed heterogeneity which leads to unbiased estimates.
The results from multivariate probit (objective one) showed that the use of CSA-practises was
positively influenced by gender of the head of the household, farm size, education of the head
of household, location, size of the household, occupation, and farmer organizations
membership. Moreover, it was found that the use of drought-tolerant maize seeds and crop
rotation was positively associated while the use of a residue-retention and crop-rotation in
combination, the use of organic manure and crop-rotation, combination of intercropping and
residue-retention and the use of intercropping and organic manure were significantly and
positively associated at significant level 1 %. This implies that farming households consider
these combinations as complements.
The study examined the determinants of farm households’ decision to use combinations CSA-
practises (objective two) and found that production diversification, gender and livestock
ownership were positively and significantly influence the usage of combinations of residue-
retention and intercropping. In addition, education level and gender of the head of the
household were positively and significantly affect in the usage of combination of crop
rotation, crop residue and intercropping This comprehensive study is significant for finer
understanding of the synergistic effect of interrelated CSA-practises.
The result for objective three found that usage of CSA-practises depends on either it is used in
isolation or in combinations, and the usage of these CSA-practises significantly increase food
variety score per adult equivalent unit when used either singly or jointly. Furthermore, the use
of intercropping in isolation show the highest food variety scores per adult equivalent unit
among all the possible combinations of CSA-practises. Moreover, the use of crop rotation in
isolation also showed a high pay off after intercropping followed by a joint combination of
crop rotation and residue retention. Thus, the usage of a combination of crop rotation,
intercropping and crop residue retention was found to be the best food security portfolio.
Results from objective four found that the characteristics of the household, plot characteristics
and institutional characteristics (e.g access to extension services) influences the usage of a
different combination of CSA-practises. The study also found that the highest payoff of food
security could be achieved when CSA-practises are used in combination than in isolation. The
combination of drought-tolerant maize seeds and irrigation gave higher payoff than the
combination of all three CSA-practises.
Finally, the findings from objective five showed that radio ownership, education of the
household head, farm experience, production diversity and livestock ownership were the
determinants of using irrigation in the study area. The average treatment effect of the treated
(ATT) and the average treatment effect of untreated (ATU) were positive and highly
significant for irrigators and non-irrigators. That is, the use of irrigation as a CSA-practise has
improved food security of the farming households.
It is recommended that, inorder in order to enhance the usage of CSA-practise, policy makers
and local government authorities should target equipping extension workers and other
agricultural practitionners with adequate items of infrastructure that enable their easy
movement to the farmers. In addition, more more extension agents should be trained and
deployed in the country to reduce the workload of the limited number of extension officers
available inoder to improve agricultural productivity and food security
The study calls for policy makers on policies and plans that promote CSA-practises as a
combination, including other interrelated practises which upscaling CSA-practises usage.
Furthermore, there is a need to promote the usage of CSA-practise in isolation or in
combination. In addition, the study suggests that based on the practises considered in this
study, usage of a combination of various practises results in better food security compared to
the usage of these practises individually. This suggests that agricultural practitioners should
promote combinations of CSA-practises to improve food security in the farming households.
It is recommended that policymakers should consider rehabilitating the existing irrigation
schemes while constructing new irrigation schemes to widen the impacts of irrigation to
household food security. However, despite the positive impact of irrigation, it is
recommended that other irrigation practises such as drip irrigation, sprinkler irrigation should
be used in the areas where construction of small-scale irrigation is not possible.
Impact Evaluation (3ie), Sokoine University of Agriculture (SUA), Wageningen University and Research center (WUR), African Green Revolution Alliance (AGRA)