Interactions of Biophysical and Socioeconomic Factors and Outputs in Mixed Crop-Livestock Smallholder Farming Systems in Africa South of the Sahara

African mixed farming is a system in which various components (cropping, tillage, soil fertility, milk and meat production) are owned and managed as a single unit. Mixed crop-livestock farming systems constitute the backbone of much smallholder agriculture in the tropics, particularly in sub-Saharan Africa. Livestock provide many different products and services to people, such as food, income, manure, draft power, a store of wealth, and socio-cultural values. Mixed crop-livestock systems are characterized by a strong complementarity in resource use, with outputs from one component being supplied to other components. However, some trade-offs between farm components are also evident. Organic resources play a dominant role in smallholders production and livelihood objectives. The organic resources are used for soil fertility management, animal feed, fuel, and fibre. Crop-livestock interactions and integration are influenced by a variety of socio-economic factors including climate, soils, population density, labour availability, land availability, market access, government policy, structural adjustment programmes, and trypanosomiasis threat. The increased variety of outputs produced in mixed smallholder crop-livestock systems reduces marketing risks associated with unexpected declines in the price of any one product. The application of remedial interventions in resource management is becoming a necessity for intensifying crop-livestock systems where population density is on the rise, the farm size is declining, and competition for land, water, and other biophysical and socioeconomic resources among various sectors is increasing. Given the growing resource scarcity and the rising demand for agricultural products, appropriate resource allocation is needed to satisfy this demand and also safeguard environmental services of ecosystems at the same time. Sustaining and safeguarding environmental services in sub-Saharan Africa cannot be realized without controlling the expansion of grazing land and cropland into natural ecosystems, and limiting and reversing rangeland degradation. Diversification and intensification of smallholder agriculture appear the most effective pathways for achieving these outcomes. Participatory research approaches involving appropriate scientific disciplines, policy makers and farmers are needed for developing ecologically sound, economically viable and socially acceptable technologies that improve nutrient cycling and enhance agricultural productivity. Property rights have a profound effect on resource management. Thus secure rights to land, whether under communal or private regimes, are required for long-term resource management. Economic incentives (e. g. subsidies) and policies that encourage well-functioning input and output markets can have a strong impact on the choices that farmers make between alternative crop, livestock and nutrient management strategies.