Role of tree crops in farming systems of some humid and semi-arid areas in Kenya
Trees grown on farms are being used as a source of firewood, food, income, fodder, and soild conservation. However, this potential has not been realized in many parts of Kenya. There is also lack of information on opportunities and constraints that have prevented farmers from planting trees for the different farming systems in the high (humid) and low potential (ASALs) areas of Kenya. Farming systems were selected in Nyeri (humid) and Mwingi (arid and semi-arid lands) districts. Information was gathered using participatory Rural Appraisal (PRA) approach and empirical field measurement s to find the range of tree crop species being utilised. Their importance was evaluated as a source of income, firewood, food and for alternative uses such as fodder, roots, and bark for medicinal purposes and soil conservation. The farmer's know how in tree management practices was also examined. Linear regression, graphical techniques, tabulations plus other descriptive methods were used for data analysis using the MS Excel 5.0 and SPSS computer programmes. Income derived from tree crops in the farming systems of arid areas of Mwingi and humid areas of Nyeri was 50% and 24% of the total farm income respectively. This indicates that tree crops function as a substantial source of income to the farmers in both humid and ASAL areas. In the sampled areas of Nyeri and Mwingi the average fruit production per hectare per year was found to be 1.7 and 1.9 tonnes respectively. Fuel wood production from trees planted on farms accounted for over 70% to 80% of the total fuel wood consumed in the households respectively. It was also found that fodder trees play a major role in livestock development in the ASALs than in humid areas. The study also found that several factors which include lack of appropriate know-how, inadequate marketing infrastructure and natural constraints such as adverse climate have significant influence on tree growing included farm size (r=0.6077), distance to the nearest market from the farms (r=0.5999), distance to the nearest forest from the farms (r=0.6038) and education status of the household head (r=0.4855). In order to enhance the role of trees this study recommends a redefined extension approach to promote tree planting. Farmers’ education on technical (practical) skills of propagation, planting and management of trees is suggested as a necessary step for realistion of benefits in tree cropping. Appropriate recognition and awareness need also to be created among policy makers who are responsible for agricultural and rural development. The significance of the study is that trees will provide useful solutions to many of the consequences of human land use, including solving energy crisis (firewood) as forest shrink in size, increased diversification of agricultural production systems, increased yields of crops and livestock, reduction of land degradation, and increased rural development.