Agricultural growth trajectories in the humid and sub-humid tropics can be broadly characterized as either expansion of extensively cropped land or land use intensification, although these exist as poles along a continuum of farmer investment in sustainable land management. This continuum usually covers a transition from conversion of natural forest or savanna, a period of rapid degradation of the land resource base and then investment and improvement in land productivity (Scherr and Hazell, 1994; Lambin et al., 2001). The degree and scope of degradation and the point at which the land resource starts to increase in value causing investment are broadly determined by population density and market conditions. In areas farthest from markets, the cost of transportation reduces this value and restricts availability of farm inputs. At the other end of the intensification spectrum are the intensively managed irrigated agricultural regions of the Asian river deltas, where low costs of inputs, inefficient water use, and poor understanding of environmental externalities results in soil and water degradation and excessive reliance upon external inputs, particularly fertilizer and pesticides. Between these two extremes lie the bulk of agricultural lands in the humid and sub-humid tropics, where production systems are essentially rainfed, dominated by smallholders, and intensification faces a number of unique constraints. This is where CRP1.2 will focus, as the extensive margin in the humid forest is central to CRP6 and the more intensive margin is the focus of CRP1.3 and GRISP (Global Rice Science Partnership).
Agricultural development in the humid and sub-humid tropics has been uneven, and is best reflected in what the World Development Report (World Bank, 2007) has called the three worlds of agriculture. In the “first agricultural world”, primarily in Sub-Saharan Africa, economies are dependent on agriculture but growth remains sluggish, and poverty predominates in rural areas. Generating agricultural growth is crucial for poverty reduction, and this must take place both where land availability is highly constrained, such as Kenya, Rwanda, Liberia and Malawi, and where land is relatively abundant, such as Mozambique, Zambia, DR Congo, Tanzania, Nigeria and Ghana. The incentives for production system intensification vary significantly across this spectrum, and yet the need to increase productivity and ensure sustainable management of the natural resource base is a constant.
The transforming economies of the “second agricultural world” are primarily found in tropical Asia. These countries are characterized by rapid economic growth, where agriculture is a declining contributor to the overall GDP (although livestock as a proportion of agricultural GDP increases), but where the number of poor is still very large and concentrated in lagging areas that have not participated in the agricultural growth process. These areas include Laos and Cambodia, eastern India and the mountainous highlands of Vietnam and Thailand. These lagging areas often have constrained access to markets, are dependent on rainfed farming systems, have trade-offs in the sustainable management of the natural resource base, and yet rely on agriculture as the means to escape poverty.
Urbanized economies are primarily found in Latin America and in these “third agricultural world” countries agriculture is highly commercialized, poverty is concentrated in urban areas, and sustainable management of natural resources drives policy formulation in relation to smallholder agriculture. This region has seen the largest increase in new land brought into agricultural production, primarily in the savanna ecosystems in the cerrados of Brazil and the llanos of Colombia and Venezuela where large-scale agriculture dominates. Apart from the drier areas of the Northeast of Brazil, most smallholder agriculture in Tropical America is concentrated in the highland systems of the Andes and Central America. It is the highland ecosystem in Latin America that is most congruent with the CGIAR’s SLOs.
Humidtropics will cover all three agricultural worlds spanning humid forests, tropical highlands, and moist savannas. All three are important for Sub-Saharan Africa, while in Asia the focus will be on the highland regions and the highly populated, humid forest regions of Indonesia, while in the Tropical Americas highland systems predominate. Choice of these ecosystems across the three continents integrates the growth dynamics of the economy with CGIAR System Level Objectives. At the same time, Humidtropics will focus on production system intensification in these agro-ecosystems outside of both the immediate forest margins and the intensive, irrigated areas of Asia. Also Humidtropics will focus on livelihoods based upon integrated agricultural production rather than those dominated by a single commodity covered within other CRPs. The program will therefore, identify and focus on farming systems where the integration of components is more important than the production of any one. This focuses the work of Humidtropics directly on rainfed smallholder farming systems and their opportunities for sustainable intensification. To fully justify the focus of the Humidtropics CRP, however, we must address why the focus on integrated production systems, what is the best approach to alleviating rural poverty in the selected agro-ecosystems, and how to scale complex technologies in order to achieve desired SLOs.
