The challenge of HIV/AIDS: Where does agroforestry fit in? - World ...

Chapter 5: Confronting land degradation in Africa45protection becomes a feature of decisionmaking at these higher scales, sometimesconflicting with the aspirations of the farmlevelland users with respect to rights ofallocation and use. Likewise, forests can beharvested by private enterprise or government,and the resultant land cover changescan influence the availability of water tolocal people.In the following discussion we deal successivelywith challenges at the scales ofplot and farm (the most common level ofconcurrence of agricultural practice andscientific exploration); the scales below theplot where biological dynamics in the soilinfluence agricultural productivity and otherecosystem services; and finally with the‘landscape’, an aggregation of scales abovethe farm. It is perhaps necessary to note thatthis chapter is predominantly concernedwith biological aspects of the managementof natural resources. Those to do with theeconomic, social, cultural and institutionalaspects are covered in Chapters 7: ‘Scalingup the impact of agroforestry’ by Franzelet al. and 8: ‘Policies for improved landmanagement in smallholder agriculture’ byPlace et al. in this volume. This is simplya matter of convenience and, hopefully, itdoes not need to be said that the biologicalproblems associated with ecosystem serviceprovision and those of the sociology of needand acceptability are inseparable and mustbe tackled holistically.Plot and farmThe degradation of soil fertility, specificallythe capacity of the soil to support agriculturalproduction, has been identified as oneof the main causes of Africa’s agriculturalfailure (Buresh et al. 1997). It has beenrecognized that the problem of soil fertilitydegradation is a microcosm of that of landdegradation as a whole. TSBF/ICRAF (2002)states: ‘The soil fertility problem remainsintractable largely because of the failure todeal with the issue in a sufficiently holisticway. Soil fertility decline is not a simpleproblem. In ecological parlance it is a slowvariable, which interacts pervasively overtime with a wide range of other biologicaland socioeconomic constraints to sustainableagroecosystem management. It is notjust a problem of nutrient deficiency butalso of inappropriate germplasm and croppingsystem design, of interactions withpests and diseases, of the linkage betweenpoverty and land degradation, of oftenperverse national and global policies withrespect to incentives, and of market and institutionalfailures such as lack of extensionservices, inputs or credit opportunities.’Tackling soil fertility issues thus requiresa long-term perspective and a holistic approachthat integrates biological and socialelements (e.g. Swift and Palm 2000). As expressedin the African Highlands Initiative,integrated natural resource managementembodies the following (Stroud and Khandelwal2001:• principles for improving livelihoods;• inclusion of the perceptions, needs,opportunities and positions of multiplestakeholders;• formulation and adoption of strategiesto better balance the differing goals ofthose primarily concerned with environment,economic growth, equity or governance;• facilitation of institutional arrangementsand linkages within organizations andbetween various actors so as to achievebetter coordination;• fostering of synergies and informationexchange between stakeholders to promotesustainable development;• promotion of institutional and technologicalinnovations and policies thatcontribute to local ownership and stewardship;and• building upon local assets (financial,physical, knowledge and skills) topromote self-determinism and limitdependency.For more than two decades, the Centreand its partners have focused on developingtechnological options for sustainablesoil management that are biologically effective,economically viable and sociallyadoptable (Raintree 1987). This work hasproduced a substantial database of empiricalknowledge, including a series ofbooks, e.g. Young (1997), Buresh et al.(1997), Bergstrom and Kirchmann (1998),Tian et al. (2001), Vanlauwe et al. (2002),Gichuru et al. (2003), Schroth and Sinclair(2003) and Bationo (2004). From this work,a number of general lessons have emerged,with significant success in adoption andimpact (see Jama et al. Chapter 6, this volume).Most of this success has been centredround the recognition that combined use ofinorganic and organic sources of nutrientshas greater benefit than either alone (Figure2). As described in these publications, themenu of available technologies is broad andthe potential for identifying the appropriateone under a given set of conditions is nowhigh. The cropping designs that promoteintegrated nutrient management include integrationof legumes as grain or cover crops,rotations and intercrops, improved fallows,integration with livestock (i.e. use of manure)and conservation tillage. Agroforestryhas contributed successful options to manyof these generic systems. A key featureof the success in soil fertility research inAfrica over the last decade has been theintegration of ecological and participatorysocial science research.The focus on integrated nutrient managementas the basis of soil fertility managementis, of course, a relearning of an oldlesson, but one that has been accompanied