State and trends of woody vegetation cover in the cotton-based farming system zone of Western Burkina Faso

This study was carried out in Bala; a village located in the cotton-based farming system zone of Western Burkina Faso. The objective was to assess the effect of increased cotton cultivation on the spatial dynamics and structural characteristics of the woody vegetation. Using aerial photos; an analysis of the land use for the years 1952; 1981 and 1999 was carried out. An inventory covering 25 smallholders' fields and fallows as well as the vegetation of a protected area (biosphere reserve of hippopotamus ponds) was carried out to evaluate the gradients of tree species richness and density. The results showed drastic changes in land use in Bala between 1952 and 1999. Cultivated areas which covered only 10 of the total land surface of the village in 1952 increased to 48 in 1999. A total of 44 woody species from 34 genera and 26 botanic families were recorded; out of which; 31 species were found in the protected area; 15 species in relatively recent fallows and 12 species in cultivated lands. Tree density in cultivated areas decreased as farmers' level of mechanization shifted from manual cultivation to partial ploughing; complete ploughing and motorized farming. On the other hand; tree species richness and density were higher both in the protected area and fallows than in cultivated lands confirming the key role that protection and fallowing play in the reconstitution of woody vegetation. Management of woody vegetation should take into account the level of mechanisation and the needs of farmers in order to sustain the production of indigenous trees on farms while allowing the intensification of the production of annual crops

Effect of land use changes on some important soil properties in cotton-based farming system in Burkina Faso

Continuous and intensive cropping without restoration of soil fertility has depleted the nutrient base of most soils in the semi arid zone. A field survey was carried out in 2000 in Bala village in the cotton production zone of western Burkina Faso to assess the effect of land use changes on soil chemical and physical changes. The methodology consisted of land use analysis at contrasted periods; field sampling and measurements; and farmers' interview. Land use analysis was done at three periods: 1952; 1981 and 1999. Soil samples were taken in farmers' fields selected on the basis of their equipment level and the cultivation duration. Two fallows were selected and considered as control situation. Aerial photos analysis showed that the proportion of the land under cultivation was increased at about 38.3 from 1952 to 1999. Soil chemical analysis showed that soil total P and K were significantly higher in soils manually cultivated than in soils cultivated with animals and tractors. Soil pH was lower in motorized farmers' fields than in the other categories. Soil organic matter and N content were not affected by all the studied factors. The percentage of sand in the soil increased with the performance of the equipment. The opposite situation was observed with soil silt content. Soil stability was not significantly affected by any of the factors. But the numerical values showed a more stable soil structure under fallows than when soils were cultivated. From the results; it appeared that the fundamental cause of land degradation in the area is the farming system than the nature of the crop being grown

Effect of land use changes on some important soil properties in cotton-based farming system in Burkina Faso

Continuous and intensive cropping without restoration of soil fertility has depleted the nutrient base of most soils in the semi arid zone. A field survey was carried out in 2000 in Bala village in the cotton production zone of western Burkina Faso to assess the effect of land use changes on soil chemical and physical changes. The methodology consisted of land use analysis at contrasted periods; field sampling and measurements; and farmers' interview. Land use analysis was done at three periods: 1952; 1981 and 1999. Soil samples were taken in farmers' fields selected on the basis of their equipment level and the cultivation duration. Two fallows were selected and considered as control situation. Aerial health facilities. There is an urgent need for health education and health promotion programmes in this population for early booking for antenatal care. Further investigations are needed to establish the risk factors for; causes of and preventive interventions for anaemia in pregnancy