Social and environmental trade-offs in tree species selection: a methodology for identifying niche incompatibilities in agroforestry

Natural resource degradation in highland regions is of increasing concern to the global community due to its role in aggravating poverty and the loss of environmental services to local and downstream users. The integration of trees into smallholder farming systems has been promoted as a means to enhance rural livelihoods while reversing the degradation of soil, water, biodiversity and related environmental services. Yet in addition to these benefits, negative impacts of trees on certain stakeholders or system components have also accompanied such efforts—suggesting that important trade-offs accompany afforestation. This paper presents a methodology for diagnosing problems stemming from cultivation of certain tree species in specific landscape niches. Data derived from the application of this methodology in two sites in the eastern African highlands are presented. Participatory diagnoses of landscape-level problems suggest that the negative impact of trees on water resource availability and crop yield are of critical concern to smallholder farmers. Ethnoecological data highlight the properties of different tree species that determine their suitability to specific farm and landscape niches. These data point to important opportunities for more socially- and environmentally-optimal integration of indigenous and exotic tree species into agricultural landscapes, and highlight the critical importance of local knowledge in forging solutions appropriate to contemporary realities.     

Adoption and adaptation of natural resource management innovations in smallholder agriculture: reflections on key lessons and best practices

Many smallholder farmers in vulnerable areas continue to face complex challenges in adoption and adaptation of resource management and conservation strategies. Although much has been learned from diverse experiences in sustainable resource management, there is still inadequate understanding of the market, policy and institutional failures that shape and structure farmer incentives and investment decisions. The policy and institutional failures exacerbate market failures, locking smallholder resource users into a low level equilibrium that perpetuates poverty and land degradation. Improved market access that raises the returns to land and labor is often the driving force for adoption of new practices in agriculture. Market linkages, access to credit and availability of pro-poor options for beneficial conservation are critical factors in stimulating livelihood and sustainability-enhancing investments. Future interventions need to promote joint innovations that ensure farmer experimentation and adaptation of new technologies and careful consideration of market, policy and institutional factors that stimulate widespread smallholder investments. Future projects should act as ‘toolboxes’, giving essential support to farmers to devise complementary solutions based on available options. Addressing the externalities and institutional failures that prevent private and joint investments for management of agricultural landscapes will require new kinds of institutional mechanisms for empowering communities through local collective action that would ensure broad participation and equitable distributions of the gains from joint conservation investments. Readers should send their comments on this paper to: BhaskarNath@aol.com within 3 months of publication of this issue.     

Agricultural productivity and environmental insecurity in the Usangu plain, Tanzania: policy implications for sustainability of agriculture

Sustainable agricultural development is a necessity for sustainable economic growth and social development in Africa. Sustainable agriculture largely depends on how effective natural and environmental resources are managed and utilized; it also depends on the security of continuous access to such resources. This research was aimed to look into trends in agricultural productivity, examine the persistence of the environmental insecurity, analyze the relationship between the two, and explore their links to the national development policies. The results are discussed in the context of relevance to national development policies and their implications on the sustainability of agriculture and rural livelihoods security. Literature survey, records collection from the stakeholders, village level participatory assessments (PAs), observations and questionnaire survey were tools used for data collection. The study shows significant (P < 0.01) declines in cereal crop yields, cattle milk yield and cattle calving rate, and increasing cattle mortality rate. Elements of environmental insecurity were found to account for decline in agricultural productivity; significant (P < 0.01) proportion (68%), of 266 households interviewed, reported land resources deterioration, declining soil fertility, and increasing drought frequencies as the causes of their low productivity. Declined fertilizer consumption and increasing variability in rainfall amount significantly (P < 0.01) accounted for 59% and 39%, respectively, of the variations observed in total annual production of rice and maize, which are major cereals in the study area. This study recommends measures to improve soil productivity such as improved fertilizer application and use of organic manures along with mineral fertilizers for maintaining soil productivity; education of farmers on sustainable use and management of land resources; and pro-poor rural policies in agricultural development and environmental governance. Readers should send their comments on this paper to: BhaskarNath@aol.com within 3 months of publication of this issue.