Ecology and Natural Resource Development in the Western Highlands of Cameroon. Issues in Natural Resource Management: Issues in Natural Resource Management

Chapter Eleven. Cropping Intensity and Post-cultivation Vegetation Successions: Developing Sustainable Agro-ecosystems in Ndop Plain, Cameroon

Chapter Eleven Cropping Intensity and Post-cultivation Vegetation Successions: Developing Sustainable Agro-ecosystems in Ndop Plain, Cameroon Summary The sustainability of traditional farming systems in many parts of Africa is threatened by losses in the variety of species, reduction in land, forest, soil and water resources under demographic pressure. Together with foreign influences these farming system are no longer in equilibrium with local culture and ecology and are therefore disintegrating due to the lack of local capacity to adjust to these changes. This has led to environmental degradation. The paper employs a combination of qualitative and quantitative techniques to: analyse the farming systems, assess the effect of cropping intensification on the climatic climax vegetation, and to establish the post-cultivation vegetation successions in fallows. It reports four crop fallow rotations: crop 3 years with 1 year bush fallow, crop 5 years with 1-2 year bush fallow, crop 10 years with 1-3 year bush fallow and continuous cropping. The post-cultivation successions present a plagioclimax dominated by Hyparhenia species with scattered shrubs maintained by cycles of cultivation and burning. The paper concludes that these shifting cultivation cycles involving cropping intensification and post cultivation savannization have deprived the farming system of its ecological benefits, that is, nutrient recycling through a long and mature fallow. The inability of the vegetation to reconstitute itself requires the development of farming systems that combine trees and crops in the field because of proven micro-ecological and ecological benefits. The paper therefore identifies the scope for the development of socially, economically and ecologically sustainable agro-ecosystems as a development path for shifting cultivation systems. 176 Ecology and Natural Resource Development in the Western Highlands of Cameroon Introduction The sustainability of agriculture in many parts of Sub-Saharan Africa is threatened by losses in the variety of species, reduction in land, forest and water resources, soil erosion, salinization, acidification, desertification and environmental pollution (Bassey and Ndenecho, 2006). Traditional farming systems which over centuries developed in constant interaction with local culture and local ecology have disintegrated because of the lack of local capacity to adjust to population growth and the influence of foreign values. The inability to mange change has led to severe environmental degradation. (Lawton and Wike, 1979; Weiskel, 1989; TAC/CGIAR, 1988). In response to these influences there has been a tendency towards intensification characterized by short duration fallows with low external inputs (Chambers et al., 1989; OTA, 1988). For most of Africa, production therefore lags behind population growth. As new technologies to intensify land use in a sustainable way have not been developed or are not known to farmers, they are often forced to exploit their land beyond its carrying capacity (Harris, 1999; Sachs, 1987). The over use of land under demographic pressure and the expansion of farm boundaries and small holdings to new, often marginal farming areas leads to deforestation, soil degradation and increased vulnerability to torrential rains and droughts (Reijintjes et al, 1992). Many African land use systems are therefore in the midst of such downward spiral of nutrient depletion, loss of vegetation cover, soil erosion and economic, social and cultural disintegration. The paper seeks to analyse the farming systems in both qualitative and quantitative terms, and to assess the role of cropping intensification on the climatic climax vegetation, and postcultivation derivatives as they relate to the development of sustainable agro-systems in peasant communities. The Study Area And Study Sites Ndop plain is an intermontane basin in the Bamenda Hyghlands (Fig. 1). The average attitude is 1200 m above sea level. It has a humid tropical climate with annual rainfall in the range of 1500 to 2000mm. The wet season lasts from mid-March to mid-November. The rest of the monthsare dry. Annual average temperature is 21.3O C. Large water deficits are experienced from December to February. 177 Cropping Intensity and Post-cultivation Vegetation Successions Fig. 1: Location of the study area (Ndop) and villages investigated Three geological formations characterize the area: granites and migmatites in the north, ancient basalts in the south, and alluvial deposits in the centre and east. The main pedomorphic units are: alluvial soils on the Nun River flood plain, alluvio - colluvial deposits on the gently undulating foot-hills in the north, soils developed on basalts and trachytes in the south and fine-grained granitic soils on undulating hillocks in the plain (Kips et al., 1987) The vegetation is mainly wooded grassland with...