Optimal Management of farm-level resources in the Lake Victoria catchments: a case of upper Rwizi and Iguluibi micro-catchments, Uganda

This study investigates use and management of farm-level resources given increasing concerns of land degradation and pollution of Lake Victoria in Uganda. It was conducted in selected sites in the upper River Rwizi and Iguluibi micro-catchments. Unsustainable agricultural expansion and other land use activities in these regions have lead to land degradation, soil erosion, pollution of Lake Victoria, soil fertility decline and decline in agricultural productivity. Remedial efforts are only in experimental phase and the contribution of agricultural activities to land degradation and pollution is not well documented. The gist of this dissertation derives the socio-economic and farm-level resource uses and management conditions under which these remedial efforts can be implemented and thus contribute to the momentous policy debate on land degradation. The following research questions guided the study:· What factors determine the adoption of soil and water conservation (SWC) technologies in the upper Rwizi micro-catchment?· Are there productivity differentials between adopters and non-adopters of SWC technologies in the upper Rwizi micro-catchment?· Are grass strips used in maize cropping as filters of sediments economically viable? · What is the linkage between smallholder farmers socio-economic and farm characteristics to seeking information on agricultural land management technologies? This dissertation is laid out in six chapters. Chapter one introduces and frames the issue of land degradation in light of changing land uses in Uganda. It also describes the study areas, sampling and data collection and finally gives a structure of how the different chapters are interrelated in the dissertation. Chapter two investigates the factors influencing the adoption of SWC technologies. A decision making framework is used to analyze the socio-economic, institutional, bio-physical, and farm structural factors that predispose smallholder farmers to adopt SWC technologies. The analysis uses cross-sectional survey data from 271 households in the upper Rwizi micro-catchment. Results reveal that the likelihood to adopt SWC technologies increases with land size, access to agricultural extension services, sex of the household head and the particular sub-county of the smallholder farmers. Findings further show that the quadratic term in land size is significant and negative, pointing to a potential acreage threshold to adoption of SWC technologies in the catchment. Chapter three analyzes efficiency differences between adopters and non-adopters of SWC technologies. Using data from a cross-sectional survey of 246 smallholder banana farmers in the upper Rwizi micro-catchment, a Cobb-Douglas stochastic production frontier is fitted after correcting for self-selection bias in the adopter and non-adopter sub-samples, using a Heckman two stage procedure. Factors that significantly contribute to technical inefficiency include education, adoption of SWC technologies and distance to markets. The estimated average technical efficiencies are significantly different between adopters and non-adopters. Banana production exhibits decreasing returns to scale. Results further reveal that banana farmers are technically inefficient, implying that there is great potential for increasing production by improving technical efficiency under the current input regimes. Chapter four addresses the economic viability of grass strips used by maize farmers as sediment filters in the Iguluibi micro-catchment. On-farm experimental data are combined with household survey data to calculate the net present values of various maize/grass strip combinations. Additionally, sensitivity analyses on discount rates and grass biomass prices are conducted. Relative to maize production without grass strips, an increment in NPV of 24%, 33% and 35% is registered for maize + Paspulum, maize + lemon and maize + elephant grass respectively. In conclusion, the farmers benefit through sale of grass biomass, reduced nutrient loss, while society benefits due to reduced sedimentation of Lake Victoria. Chapter five investigates the factors that predispose smallholder farmers to seek agricultural information from various sources and channels in the upper Rwizi and Iguluibi micro-catchments. Using pooled cross-sectional data of 369 households, a probit model is fitted. Findings indicate that the farmers use a variety of information sources and channels; radio programs, district farmers organizations, fellow farmers and the National Agricultural Advisory Services. Results further reveal that membership in farmers groups, level of education, farming experience, farm size and the location of farmers significantly influence the probability to seek information from various sources. These results reiterate the importance of broadening the scope, sources and content of agricultural information to cater for all farmers across the spectrum. In chapter six, conclusions and salient policy recommendations for improving management of farm-level resources and reducing land degradation of Lake Victoria catchments are given. More specifically, it is advised to (1) improve smallholders access to demand-driven agricultural extension services, (2) incorporate gender dimensions in research, technology generation and dissemination, (3) stimulate suitable marketing infrastructure and other support services, and (4) invest in human capital to improve labor productivity and technical efficiency.

Publication year:2013

Accessibility:Open