DEDICATION
To the almighty God
To our dear families
AKNOWELEDGEMENTS
This dissertation could not have finished without the support
we received from different persons and the National University of Rwanda; we
would like to express our sincere thanks to all those people.
We highly appreciate the invaluable guidance offered to us by
supervisor Ir Charles BUCAGU Msc, his constrictive instructions and suggestions
provided a basis of the completion of this work.
Warm thanks go to the authorities of the faculty of
agriculture and all lectures for their intelligent and useful advice they
rendered to me.
Our thanks go to our colleagues who have always been there
during our studies and in research processes.
We would like to thank our parents who have sacrificed their
meager income to educate us.
Thank you very much.
Alain
KALISA and Naphtal NSHIMYUMUKIZA
ABSTRACT
Farmers' resource management strategies affect strongly on
farm activities and are also basic determinant of farmers' soil fertility
status; however those strategies are also in relation with farmers' wealth
status. Causes of variability in soil fertility management at different scale
of analysis are both biophysical and socio-economic. Such heterogeneity is
categorized in this study which interest was to analyze the functioning of
different farming systems by establishing their major characteristics and
estimating the level of nutrient at farm and plots scales in Shanga cell
located in plateau central agroecological zone. For the assessment of
socio-economic factors, we used questionnaires during the survey and in order
to determine the variation from one plot to another, a soil analysis was done.
Three wealth groups were identified using socio-economic information and
considering production activities, household objectives and the main
constraints faced by farmers. Soil fertility management and nutrient resource
flows were studied for each wealth category and related to differences in soil
fertility status at farm scale. The first category is the well-off farmer who
owned more than 2 cows, 1000 or more coffee trees plus 1ha or more of land and
other resource allocation. Second category of intermediate farmer has less than
2 cows, coffee trees between 200 and 500 and less than one hectare of land.
They have normally enough food for their family and sometimes surplus for
markets. Poor farmer is the last category that has or not animal, 100 trees of
coffee and own a small farm less than 0.5 ha. Soil analysis result confirms
that there is strong soil fertility gradient across farms and between farms
selected from different wealth farmer categories in the order: (well off farmer
> intermediate> poor farmer) and within farm; closest field more fertile
than mid field and the later field more fertile than the remote fields. The
variability of nutrients in farm or in wealth categories is caused by
differences in resource allocation strategies.
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