Jeremias Mowo

Evergreen Agriculture: a robust approach to sustainable food security in Africa

Producing more food for a growing population in the coming decades, while at the same time combating poverty and hunger, is a huge challenge facing African agriculture. The risks that come with climate change make this task more daunting. However, hundreds of thousands of rain fed smallholder farmers in Zambia, Malawi, Niger, and Burkina Faso have been shifting to farming systems that are restoring exhausted soils and are increasing food crop yields, household food security, and incomes. This article reviews these experiences, and their broader implications for African food security, as manifestations of Evergreen Agriculture, a fresh approach to achieving food security and environmental resilience. Evergreen Agriculture is defined as the integration of particular tree species into annual food crop systems. The intercropped trees sustain a green cover on the land throughout the year to maintain vegetative soil cover, bolster nutrient supply through nitrogen fixation and nutrient cycling, generate greater quantities of organic matter in soil surface residues, improve soil structure and water infiltration, increase greater direct production of food, fodder, fuel, fiber and income from products produced by the intercropped trees, enhance carbon storage both above-ground and below-ground, and induce more effective conservation of above- and below-ground biodiversity. Four national cases are reviewed where farmers are observed to be applying these principles on a major scale. The first case involves the experience of Zambia, where conservation farming programmes include the cultivation of food crops within an agroforest of the fertilizer tree Faidherbia albida. The second case is that of the Malawi Agroforestry Food Security Programme, which is integrating fertilizer, fodder, fruit, fuel wood, and timber tree production with food crops on small farms on a national scale. The third case is the dramatic expansion of Faidherbia albida agroforests in millet and sorghum production systems throughout Niger via assisted natural regeneration. The fourth case is the development of a unique type of planting pit technology (zai) along with farmer-managed natural regeneration of trees on a substantial scale in Burkina Faso. Lastly, we examine the current outlook for Evergreen Agriculture to be further adapted and scaled-up across the African continent.

Understanding patterns of tree adoption on farms in semi-arid and sub-humid Ethiopia

Trees on farms are a widespread feature of landscapes across a large part of Ethiopia with an important role in enhancing the resilience of smallholder livelihoods through the provision of ecosystem services. Despite their importance, little is known about what trees are planted or retained from natural regeneration by different types of farmers that results in the pattern of tree cover found in the region. We address this knowledge gap through analysis of household survey data from semi-arid and sub humid areas of Oromia regional state. A set of composite variables that represent distinctive patterns of tree cover on farms were derived from principal component analysis and Pearson correlation analysis. This revealed two major tree adoption strategies: farmer managed natural regeneration (FMNR) of trees to meet subsistence needs as well as contributing to other ecosystem services; and, high value agroforestry (HVAF) involving planted trees used largely to produce fruits, timber and fodder. Regression analysis further identified fine-scale variation in ecological and socio-economic factors that affect which of these two broad strategies are adopted by farmers. Favorable climatic conditions coupled with institutional arrangements to control free grazing were pre-conditions for HVAF, whereas poor biophysical potential and sloping land provided a positive incentive for farmers to adopt FMNR. Farmers with preferences for tree species with multiple utilities and locational flexibility favored FMNR while adoption of HVAF was more asset-driven. Our findings reveal that farmers integrate many native and exotic tree species on their farms to meet their variable farm conditions, needs and asset profiles in stark contrast to most tree promotion efforts that focus on a few, usually exotic, tree species. We recommend that future agroforestry promotion should embrace a diversity of tree species appropriate to matching the fine scale variation in ecological conditions and farmer circumstances encountered in the field.

Formalisation of local herbal product markets has potential to stimulate cultivation of medicinal plants by smallholder farmers in Kenya

Trade in medicinal tree products is rising in urban centres of the developing world, posing a threat to biodiversity. Cultivation of medicinal plants is a viable alternative source of raw materials, but evidence on whether traders are willing to source from farms is lacking. In this study, it was assumed that an increase in consumer awareness would stimulate the creation and growth of formal enterprises dealing in herbal medicine, through demand for medicinal products that are better packaged and labelled as compared to openly sold plant parts. The study sought to establish whether medicinal plant traders in Kenya sourced raw materials from smallholder farmers and whether there was potential to raise cultivation levels of medicinal trees by smallholders with increased formalisation of enterprises. The study interviewed 55 herbal medicine enterprises classified as herbal clinics, final product enterprises, and herbal semiprocessing enterprises in four major cities of Kenya and 200 farmers in an area close to Mt. Kenya, where trees are in abundance on the farms there. The enterprises in the final products category were more recent, were the fastest growing, and sourced raw materials mostly from farms through purchasing. Most farmers in our study were not aware of opportunities to sell medicinal plant products, but those who sold products from other tree categories responded by planting more of those trees. Policies that facilitate herbal enterprises to buy more from farmer groups as well as economic analysis of the best candidate medicinal tree species for cultivation as alternative crops are recommended.

Conceptual Analysis: The Charcoal-Agriculture Nexus to Understand the Socio-Ecological Contexts Underlying Varied Sustainability Outcomes in African Landscapes

The production of charcoal is an important socio-economic activity in sub-Saharan Africa (SSA). Charcoal production is one of the leading drivers of rural land-use changes in SSA, although the intensity of impacts on the multi-functionality of landscapes varies considerably. Within a given landscape, charcoal production is closely interconnected to agriculture production both as major livelihoods, while both critically depend on the same ecosystem services. The interactions between charcoal and agricultural production systems can lead to positive synergies of impacts, but will more often than not result in trade-offs and even vicious cycles. Such sustainability outcomes vary from one site to another due to the heterogeneity of contexts, including agricultural production systems that affect the adoption of technologies and practices. Trade-offs or cases of vicious cycles occur when one-off resource exploitation of natural trees for charcoal production for short-term economic gains permanently impairs ecosystem functions. Given the fact that charcoal, as an important energy source for the growing urban populations and an essential livelihood for the rural populations, cannot be readily substituted in SSA, there must be policies to support charcoal production. Policies should encourage sustainable technologies and practices, either by establishing plantations or by encouraging regeneration, whichever is more suitable for the local environment. To guide context-specific interventions, this paper presents a new perspective - the charcoal-agriculture nexus - aimed at facilitating the understanding of the socio-economic and ecological interactions of charcoal and agriculture production. The nexus especially highlights two dimensions of the socio-ecological contexts: charcoal value chains and tenure systems. Combinations of the two are assumed to underlie varied socio-economic and ecological sustainability outcomes by conditioning incentive mechanisms to affect the adoption of technologies and practices in charcoal and agriculture productions. Contrasting sustainability outcomes from East Africa are presented and discussed through the lens of the charcoal-agriculture nexus. The paper then concludes by emphasizing the importance of taking into account the two-dimensional socio-ecological contexts into effective policy interventions to turn charcoal-agriculture interactions into synergies.

By-laws formulation and enforcement in natural resource management: lessons from the highlands of eastern Africa

Abstract Degradation of land, water and vegetation in the highlands of eastern Africa is on the increase in the face of the enforcement of natural resource management (NRM) policies and related by-laws. In this study, reasons behind the limited contribution of NRM by-laws in arresting degradation of natural resources in the highlands of Ethiopia, Tanzania and Uganda are presented, and opportunities to improve effectiveness identified. Using key informants’ interviews, focus group discussions, workshops, case studies and literature review, it is shown that inadequate community participation in the process of by-laws formulation and enforcement is the main reason for the ineffectiveness of most NRM by-laws in the three countries. When communities are fully involved in the process of NRM by-laws formulation and enforcement and both conventional and indigenous by-laws enforcement mechanisms are adopted, incidences of abuse of natural resources were reduced by as much as 50% in some of the study sites.

Does strengthening technical capacity of smallholder farmers enhance adoption of conservation practices? The case of conservation agriculture with trees in Kenya

Despite decades of agricultural extension programmes, participatory research projects and efforts to encourage knowledge integration and sharing, few smallholder farmers are adopting natural resource management (NRM) practices. Using an agroforestry (AF)-based conservation practice known as conservation agriculture with trees as a case study, this study aims at contributing to the growing debate that a properly designed training programme enhances adoption of knowledge intensive NRM practices by providing resource poor farmers with the opportunity to learn, test and adapt such practices to suit their resource needs. To control for endogeneity in participation in training and assess the effect of training on adoption, we estimate an instrumental variable probit model using cross sectional data collected in 2013 from 198 farm households in Machakos district in Kenya. One key message emanating from the study, which is critical for development practitioners who are keen on up-scaling AF based conservation practices through training, is that strengthening technical capacity of smallholder farmers is necessary but it is not in itself sufficient to stimulate adoption of conservation practices. Instead, institutional factors like good road infrastructure that help reduce transaction costs associated with the search for information on technologies and markets and resource endowments in form of labour and land provide synergistic effects. Consequently, complementary strategies such as the introduction of cost effective labour saving technologies and the provision of enabling environment through public–private partnerships for farmers to access the technologies and inputs that are critical for implementing the skills acquired during the training are prerequisites for adoption.

Households’ Choices of Fuelwood Sources: Implications for Agroforestry Interventions in the Southern Highlands of Tanzania

Fuelwood is the main source of energy for various household uses in many developing countries; and management of tree resources where it is obtained can be best undertaken when household choice patterns are understood. In this paper, households’ decision to obtain fuelwood for domestic consumption as influenced by household and fuelwood source characteristics is analyzed using a multinomial probit regression model. Data is obtained from 254 randomly selected household drawn from Mbarali district, south-western Tanzania. Results indicate that households are heavily dependent on natural forests for household energy provision and that the choice to obtain fuelwood from the forest, farm or market depends, among other factors on the availability of preferred fuelwood tree species at these sources. Acacia tortilis, Brachystegia spp. and Faidherbia albida are the significantly preferred tree species and hence affect the decision of where to obtain fuelwood. This revelation highlights the pressure applied to surrounding forests as well as to the aforementioned tree species which require immediate management interventions. The gender of the household head and whether the household lives in peri-urban or rural areas also influence choice of fuelwood source. Promotion of tree planting and on-farm management of tree species similar to preferred species found in natural forests is recommended. To the extent that consumer preferences are likely to change over time, further research using panel datasets is necessary to unravel inter-temporal preferences for fuelwood sources.

Variation in the response of eastern and southern Africa provenances of Faidherbia albida (Delile A. Chev) seedlings to water supply: A greenhouse experiment

Rural communities value Faidherbia albida in farming systems and pastoralism. Faidherbia albida provides products such as medicine, fodder, fuel, wood, food and services such as shade, soil fertility and nutrient cycling. Excessive browsing by animals, branch lopping and pod harvesting, have critically reduced the natural regeneration in some areas which exposes it to challenges due to dependence upon natural regeneration. The objective of this research was to evaluate response of Faidherbia albida provenances from eastern (Taveta Wangingombe) and southern Africa (Lupaso, Kuiseb Manapools) to different watering regimes to aid in selection of provenances for domestication. The observed difference in growth was analyzed to determine whether they are genetic or environmentally induced. Genotype × interaction were significant at (p≤0.001, p≤0.05) in seedling height, diameter and leaf numbers. Seedling height (r=0.94 p=0.001) recorded the highest correlation coefficient among all the growth variables analyzed. The growth variation was greater for seedling height than that of diameter and leaf numbers (h2=0.97). Hierarchical cluster analysis grouped the provenances into three clusters with cluster iii consisting of Taveta, Kuiseb and Lupaso while cluster ii and i composed of Wangingombe and Manapools respectively. Manapools recorded the highest genetic distance from Taveta, Kuiseb and Lupaso at 84.55 units. Wangingombe and Manapools are closely related genetically at a distance of 7.32. The maximum inter-cluster distance between cluster i and iii indicated wider genetic diversity between the provenances in these clusters and selection should be from this clusters for hybridization program to achieve novel breeds.