This article was published in the above mentioned Springer issue.The material, including all portions thereof, is protected by copyright;all rights are held exclusively by Springer Science + Business Media.

The material is for personal use only;commercial use is not permitted.

Unauthorized reproduction, transfer and/or usemay be a violation of criminal as well as civil law.

ISSN 1876-4517, Volume 2, Number 3

ORIGINAL PAPER

Evergreen Agriculture: a robust approach to sustainable foodsecurity in Africa

Dennis Philip Garrity & Festus K. Akinnifesi & Oluyede C. Ajayi &Sileshi G. Weldesemayat & Jeremias G. Mowo & Antoine Kalinganire &

Mahamane Larwanou & Jules Bayala

Received: 1 March 2010 /Accepted: 30 June 2010 /Published online: 28 August 2010# Springer Science+Business Media B.V. & International Society for Plant Pathology 2010

Abstract Producing more food for a growing population inthe coming decades, while at the same time combatingpoverty and hunger, is a huge challenge facing Africanagriculture. The risks that come with climate change makethis task more daunting. However, hundreds of thousandsof rain fed smallholder farmers in Zambia, Malawi, Niger,and Burkina Faso have been shifting to farming systemsthat are restoring exhausted soils and are increasing foodcrop yields, household food security, and incomes. Thisarticle reviews these experiences, and their broader impli-cations for African food security, as manifestations ofEvergreen Agriculture, a fresh approach to achieving foodsecurity and environmental resilience. Evergreen Agricul-ture is defined as the integration of particular tree speciesinto annual food crop systems. The intercropped treessustain a green cover on the land throughout the year tomaintain vegetative soil cover, bolster nutrient supplythrough nitrogen fixation and nutrient cycling, generategreater quantities of organic matter in soil surface residues,improve soil structure and water infiltration, increasegreater 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 arereviewed where farmers are observed to be applying theseprinciples on a major scale. The first case involves theexperience of Zambia, where conservation farming pro-grammes include the cultivation of food crops within anagroforest of the fertilizer tree Faidherbia albida. Thesecond case is that of the Malawi Agroforestry FoodSecurity Programme, which is integrating fertilizer, fodder,fruit, fuel wood, and timber tree production with food cropson small farms on a national scale. The third case is thedramatic expansion of Faidherbia albida agroforests inmillet and sorghum production systems throughout Nigervia assisted natural regeneration. The fourth case is thedevelopment of a unique type of planting pit technology (zai)along with farmer-managed natural regeneration of trees on asubstantial scale in Burkina Faso. Lastly, we examine thecurrent outlook for Evergreen Agriculture to be furtheradapted and scaled-up across the African continent.

Keywords Agroforestry . Burkina faso . Climate changeadaptation and mitigation . Conservation farming .

Evergreen Agriculture . Faidherbia albida . Fertilizer trees .

Malawi . Niger . Soil carbon . Zambia

The challenge for Africa

Despite accelerating globalization, food security inmost of thedeveloping world depends upon local food production (Funkand Brown 2009). Most rural households in developingnations are involved in agriculture and most food is producedand consumed locally (Lamb 2000). Thus, local agricultural

D. P. Garrity (*) : J. G. MowoWorld Agroforestry Centre,PO Box 30677-00100, Nairobi, Kenyae-mail: d.garrity@cgiar.org

F. K. Akinnifesi :O. C. Ajayi : S. G. WeldesemayatWorld Agroforestry Centre,PO Box 30798, Lilongwe, Malawi

A. Kalinganire : J. BayalaWorld Agroforestry Centre,BP E5118 Bamako, Mali

M. LarwanouAfrican Forest Forum,Nairobi, Kenya

Food Sec. (2010) 2:197–214DOI 10.1007/s12571-010-0070-7

Author's personal copy

production is critical to both food security and economicdevelopment among the rural poor, and increasing itsproductivity remains a central food security issue (Devereuxand Maxwell 2001; Schmidhuber and Tubiello 2007).

For the first time in history, there are more than 1 billionundernourished people in the world—increasing the urgencyof tackling food insecurity and improving agriculture. Themost severe deprivation is increasingly concentrated in sub-Saharan Africa, which is currently home to three-quarters ofthe world’s ultra poor (income less than US$0.50 per personper day) and has experienced a significant increase in thenumber of ultra-poor since 1990 (Ahmed et al. 2007). Some218 million people in Africa struggle with hunger daily -about 30% of the continent’s total population. The popula-tion of Africa is projected to grow from about 796 million in2005 to 1.8 billion by 2050 (United Nations 2004). Africaexperienced considerably faster population growth than anyother major geographical area for most of the 1950–2000period, and the countries with the fastest-growing populationsin the next half-century will be mainly in sub-Saharan Africa(United Nations 2004). Despite urban migration, the numberof rural dwellers will also continue to grow. However, percapita food production in Africa declined by almost 20%between 1970 and 2000 (Abdulai et al. 2004).

Agriculture contributes around 25% of GDP in Africa andprovides jobs for 70% of the labour force, as well as alivelihood for more than 65% of the population. Land holdingshave consistently shrunk in size due to rapid populationgrowth rates. Eighty percent of the continent’s farms nowoccupy less than 2 hectares. The dominance of smallholderagriculture means that short- and medium-term agriculturalgrowth and poverty reduction prospects will be closely linkedwith the successful transformation of this sector.

Crop output in Africa has been increasing, but this islargely driven by the expansion of cultivated land rather thanproductivity gains (Food and Agriculture Organization of theUnited Nations 2008). Between 1990 and 2006 the areaunder cultivation increased by more than 10% annuallywhile cereal yields over the same period were largelystagnant. The average yields of grain crops in sub-SaharanAfrica have stayed below 1 t/ha since the 1960s, comparedwith average cereal yields of 2.5 t/ha in South Asia and 4.5 t/ha in East Asia (Food and Agriculture Organization of theUnited Nations 2008). The uncertainty of obtaining highercrop yields is further worsened by the prevailing erraticweather conditions and future climate change (Jones andThornton 2003). Most farmers are forced to grow the samefood crops, year after year, on the same plot of land, withoutadequate fertilization or soil replenishment measures. Fertil-izer use by smallholder farmers has remained at the very lowlevels of about 8–10 kg of nutrients per hectare. Currently,fertilizer prices are double their levels in 2006, and Africaaccounts for less than 1% of global fertilizer consumption.

The use of fertilizers by smallholders to replenish their soilsis often not economically feasible, due to high prices and therisk of drought stress. The consequences are land degradation,low yields, persistent poverty and widespread malnutrition(Lal 2009).

Producing more food for a growing population in thecoming decades, while at the same time combating povertyand hunger, is a huge challenge facing African agriculture.Currently, the future picture is dire. Current projections arethat higher temperatures and lower rainfall in parts of Africa,combined with a doubling of the population, will lead to a43% increase in food insecurity, and will induce a 60%increase in food aid expenditures during the next 2 decades(Funk and Brown 2009). These figures are significantbecause food aid is an indicator of many related problems,including child malnutrition and a decline in health,productivity and economic growth (Food and AgricultureOrganization 2007). If the observed 1982–2002 trendcontinues, the 200 million undernourished sub-SaharanAfricans in 2002 will increase to almost 600 million by2030. The interaction between drought and decliningagricultural capacity may be socially explosive, politicallydangerous, and costly, with annual aid totals projected toincrease by 83% by 2030 (Funk and Brown 2009).

At least a doubling of agricultural yields is required overthe coming decades (SEI 2005) in economies where amajority of the populations depend on smallholder rain fedfarming. Approximately 65% of agricultural land in SSA issubject to degradation (UNEP/ISRIC 1991; GEF 2003).Reversing the trend of soil fertility depletion in Africanfarming systems has become a major development policyissue on the continent (Scoones and Toulmin 1999).Restoring soil health is often the first entry point forincreasing agricultural productivity, because soil nutrientdepletion is extreme in most areas where farmers havesmallholdings (Sanchez and Swaminathan 2005).

The most urgent need is to increase biomass productionin the farming system with richer sources of organicnutrients to complement whatever amounts of inorganicfertilizers that a smallholder farmer can afford to apply. Theintegration of fertilizer trees into food crop agriculture is apromising, but underappreciated, approach to accomplishingthis (Garrity, 2004). This portfolio of options is now referredto as Evergreen Agriculture. The major experiences withEvergreen Agriculture and its broader implications forAfrican food security are reviewed in this article.

What is Evergreen Agriculture?

Evergreen Agriculture is defined as the integration of treesinto annual food crop systems. Depending upon whichwoody species are used, and how they are managed, their

198 D.P. Garrity et al. Author's personal copy

incorporation into crop fields and agricultural landscapesmay contribute to:

& maintaining vegetative soil cover year-round (Boffa,1999),

& bolstering nutrient supply through nitrogen fixation andnutrient cycling (Barnes and Fagg, 2003),

& enhanced suppression of insect pests and weeds (Sileshiet al. 2006),

& improved soil structure and water infiltration (Chirwa etal. 2007),

& greater direct production of food, fodder, fuel, fiber andincome from products produced by the intercroppedtrees (Garrity, 2004),

& enhanced carbon storage both above-ground and below-ground (Makumba et al. 2007),

& greater quantities of organic matter in soil surfaceresidues (Akinnifesi et al. 2007),

& more effective conservation of above- and below-ground biodiversity (Scherr and McNeeley, 2009).

About half of all agricultural land in the world nowhas greater than 10% tree cover (Zomer et al. 2009). Insome regions tree cover on farmlands averages over 30%.In many countries the agroforestry area is steadilyincreasing.

Evergreen farming systems feature both perennial andannual species (trees and food crops). The overall indicatorof their effectiveness is that of building a healthy soil andenvironment to enhance food crop production and increasehousehold income, while increasing the resilience of thefarm enterprise to a variety of risks. They are intended todeliver extended growing seasons, increased productivity,better water utilization efficiency, and drought resilience.The overall benefits expected of an evergreen farmingsystem are increased food crop yields and/or overallprofitability, lower costs of production, and healthier soils(Garrity, 2004).

The term Evergreen Agriculture denotes that a greencover is maintained on the land throughout the year. It isone of several types of agroforestry, in this caseinvolving the direct and intimate intercropping of treeswithin annual crop fields (Arnold and Dewees 1995).Thus, it does not encompass agroforestry systems thatfeature trees maintained on fallow land, trees monocropped onarable land (i.e. farm forests), or combinations of perennialtree species on arable land (e.g. complex agro forests orperennial home gardens (Kumar and Nair, 2006)).

Evergreen Agriculture contributes to integrated soilfertility management (ISFM), which is the application ofsoil fertility management practices, and the knowledge toadapt these to local conditions, that maximize fertilizerand organic resource use efficiency and crop productivity(Sanginga and Woomer, 2009). It is also compatible with

reduced tillage, increased residue retention on the soilsurface, and other principles of conservation agriculture insituations where these are feasible and appropriate (seenext section). Evergreen Agriculture also broadens theprinciple of crop rotations to encompass the role offertilizer trees and/or other cash crop trees to enhance soilfertility more effectively and provide needed biologicaland income diversity in the farm system (Garrity, 2004).In this respect, the types of intercropped trees may includespecies whose primary purpose is to provide products orbenefits other than soil fertility replenishment alone, suchas fodder, fruits, timber, and fuel wood. In such cases thetrees are expected to provide an overall value greater thanthat of the annual crop within the area that they occupy perm² in the field.

The principles of Evergreen Agriculture have alreadybeen widely applied in Africa, where complexity is acommon feature of the agricultural systems. The followingsections review the experiences in each of four countrieswhere they have been adapted in a diversity of situationsby hundreds of thousands of farmers, often buildingsuccessfully on proven indigenous farming technologies(Table 1).

Evergreen Agriculture in Zambia

In Zambia, maize production is the foundation of agricul-ture and the basis for the country’s food supply. However,the average maize yield is only 1.1 t/ha. Sixty-nine percentof Zambian smallholders farm without mineral fertilizers.Seventy-three percent fail to produce enough maize to sellin the market. Between 2002 and 2008, a variety of factors,including low soil fertility, drought, and late planting, led to33% of the area under maize in Zambia being abandonedbefore it was harvested.

Since 1996, a coalition of stakeholders from the privatesector, government and donor communities has promoted apackage of agronomic practices for smallholders in Zambiabased on the principles of conservation farming (Haggbladeand Tembo 2003). The effort is spearheaded by the ZambianConservation Farming Unit (CFU) - (www.conservationagriculture.org). To date, conservation agriculture has beenintroduced over large areas of the country. The system thatis advocated involves:

& Dry-season land preparation using minimum tillagemethods (either ox-drawn rip lines or hand-hoe basinslaid out in a precise grid);

& Retention of crop residue from the prior harvest ratherthan burning it in the field;

& Planting and mineral fertilizer input application in fixedplanting stations in successive years;

Evergreen Agriculture: sustainable food security in Africa 199 Author's personal copy

& Crop rotations that include nitrogen-fixing species; and& Faidherbia albida trees grown in the crop fields as a

permanent canopy to increase soil fertility, planted at adensity of 100 trees per hectare, and later thinnedgradually down to 25 trees per hectare.

This system enables farmers to plant with the first rainswhen the crop plants will benefit from the initial nitrogenflush in the soil. By breaking pre-existing plow-panbarriers, the planting basins and rip lines are claimed toimprove water infiltration, water retention and plant rootdevelopment. The precise layout of grids and planting linesenables farmers to place any fertilizer and/or organicmaterial in close proximity to the plants, where they willprovide the greatest benefits (Haggblade and Tembo, 2003).Aagard (2009) has estimated that more than 160,000families have adopted the practices.

Results from a survey of 125 farms in Central andSouthern provinces during the 2001/2 cropping seasonindicated that, on average, hand-hoe CF farmers produced1.5 tons more maize and 460 kg more cotton per hectarethan did farmers practicing conventional ox-plow tillage(Haggblade and Tembo 2003). Among maize farmers,1.1 tons of this increase was estimated to result from theCF technology, 400 kg from early planting and 700 kg fromwater harvesting and greater precision in input use in thebasins. The remaining 400 kg was attributed to higherdoses of fertilizer, lime and high-yielding maize seeds.Cotton farmers use standard packages of seed and pesti-cides. The observed gains in cotton production with CFcame from water harvesting and precision and timeliness ofthe CF system. CF agriculture enables farmers to preparetheir land during the dry season, reduce land preparationcosts, and plant as soon as the first rains arrive.

One of the main goals attributed to CF is to stimulatebiological activity and improve soil structure. To do this,farmers are encouraged to keep the soil covered withorganic matter throughout the year. This involves theretention of crop residues: Conventionally, farmers tend toburn them. And it involves the rotation of maize with other

crops, particularly cotton and grain legumes, and/or theplanting of cover crops such as sun hemp (Crotalariajuncea). The additional benefits of CF—including im-proved soil structure, gains from nitrogen-fixing croprotations and reduced field preparation labor—occurgradually. Evidence from similar experiences in otherparts of Africa suggests that the effectiveness of conser-vation farming will also vary across regions and acrosscrops, due to variations in soils and rainfall. Therefore, itwill be important to establish long-term monitoring effortsfor conservation farming and control plots across a broadrange of geographic settings, crops and seasons.

The value of conservation farming to Zambian agricultureis well-recognized by the government, and receives strongpolicy and extension support by the Ministry of Agriculture.Increasingly, the country’s key donors (particularly Norway)have invested in the work of the Conservation Farming Unit,supporting the research effort and strengthening the extensionsystem in order to expand its ability to reach more farmerseach year.

Achieving Evergreen Agriculture by integrating fertilizertrees into conservation farming

As the Zambian Conservation Farming Unit (CFU) workedto develop solutions to make conservation farming feasiblefor smallholders, they encountered a problem that defiedconventional solutions. More than two-thirds of theirsmallholder clientele cannot afford inorganic fertilizers,and have little or no access to manure or other nutrientsources. This fundamentally limited smallholder maizeyields, and further depleted their soil fertility each year.To address the problem the Zambian CFU investigated theincorporation of Faidherbia albida trees into maizeproduction systems.

Faidherbia is a nitrogen-fixing acacia species that isindigenous to Africa and is widespread throughout thecontinent. What makes it unique is its growth habit, knownas ‘reverse leaf phenology’ (Barnes and Fagg 2003).Faidherbia goes dormant and sheds its foliage during the

Table 1 Attributes of Evergreen Agriculture in four African countries

Country Zambia Malawi Niger B Faso

Evergreen AgricultureSystem

Conservation farmingwith Faidherbiafertilizer trees

Portfolio of agroforestryspecies including a rangeof fertilizer trees

Assisted Natural Regenerationof Faidherbia + other trees

Zai plantingpits + ANRa

Farming system Maize, cotton Maize Millets, sorghum integrated withlivestock

Millets, sorghum

Scaling-up methods Extension with leadfarmer model

Whole-villagemobilization

Community-based resourcemanagement institutions

Projects & farmer-to-farmer training

Extent of uptake >160,000 farms >120,000 farms >4.8 mha >200,000 ha

a Assisted Natural Regeneration

200 D.P. Garrity et al. Author's personal copy

early rainy season, at the time when field crops are beingestablished. Its leaves only regrow at the end of the wetseason. This unusual phenology makes it highly compatiblewith food crops, since it does not compete with themsignificantly for light, nutrients or water during the growingseason. On the contrary, annual crops in the vicinity ofFaidherbia trees tend to exhibit improved performance andyield (Barnes and Fagg 2003).

Numerous published reports have recorded increases inmaize grain yield when grown in association with Faid-herbia. These reports range from increases of 6% to morethan 200% (Barnes and Fagg 2003), depending on the ageand density of trees, agronomic practices used and theweather conditions. Faidherbia’s effects tend to be mostremarkable in conditions of low soil fertility. In Zambia,results of 15 sets of observations conducted by the CFU inthe 2008 growing season found that unfertilized maizeyields in the vicinity of Faidherbia trees averaged 4.1 t/ha,compared to 1.3 t/ha nearby but beyond the tree canopy(Aagard 2009). Similar results were obtained in the 2009growing season (Fig. 1). The work also drew on observa-tions in Malawi, where maize yields were increased up to280% in the zone under the tree canopy compared with thezone outside the tree canopy (Saka et al. 1994).

The association between Faidherbia albida and increasedcrop yields is well documented. Barnes and Fagg (2003)noted in their comprehensive monograph on the species that“there has been a huge amount published on the beneficialeffect of Faidherbia albida on the soil once it is established”.Most of these studies have observed significant increases inyield beneath or near the trees. They observed that the tree isfound over a wide range of soils and climates and withvaried plant and animal associates, from desert to wet

tropical climates. However, it does not tolerate competitionfrom other plant species, and thus does not have invasivetendencies.

The Zambian CFU recommends that Faidherbia seed-lings be planted in a grid pattern at 100 trees per ha. Fieldswith Faidherbia-maize systems managed with such aplanting pattern (10 m×10 m) can accommodate fullmechanization. The result is a maize farming system underan agroforest of Faidherbia trees (Fig. 2). The trees maylive for 70–100 years, providing inter-generational benefitsfor a farm family, with a very modest initial investment. Asthe trees mature, and develop a spreading canopy, they aregradually thinned down to about 25–30 trees per hectare.

There is increasing recognition of the opportunity toexploit the abilities of Faidherbia, and in recent years moreconcerted efforts have been made to improve and enhancethis indigenous African agroforestry system in many partsof the continent (Garrity, 2010). Currently, the departmentsof agriculture in Zambia and in Malawi are encouragingfarmers to establish Faidherbia trees in their maize fields,the aim being to increase food production. The ZambianCFU estimates that the tree is now cultivated in conserva-tion farming systems over an area of 300,000 hectares(http://www.new-ag.info/developments/devItem; http://www.agfax.net/radio/detail). The efforts are backed bynational policy and supported by the Zambia NationalFarmers Union (Smith 2009).

Further research is needed to quantify the time stream ofbenefits on nitrogen fixation and soil fertility of incorpo-rating trees from when they are newly planted. Research isalso needed on the genetic variation in Faidherbia albidaso that strategies can be implemented to safeguard and

Fig. 2 Faidherbia fertilizer trees in a maize conservation agriculturalproduction system. National recommendations in Malawi and Zambiaare to plant Faidherbia at 100 trees per ha. Trees are 9 years old.Zambia. 2009. Photo: P Aagard

Fig. 1 Maize may exhibit dramatic productivity increases inassociation with Faidherbia albida. Note differences in maize growthunder the tree versus outside the canopy with the same managementpractices applied and zero inorganic fertilization. Zambia, 2009.Photo: D Garrity

Evergreen Agriculture: sustainable food security in Africa 201 Author's personal copy

utilize the species’ genetic diversity, and superior germ-plasm can be made available to farmers.

Planting Faidherbia requires some patience on the partof the farmer and development-support institutions. It is oneof the fastest-growing acacia species, but its initial growthis slow as it develops a deep root system. It therefore takesa few years before the trees begin to provide substantial leafbiomass and fertility benefits. In a survey of 300 farmerswith Faidherbia in their maize fields, one-third of thefarmers indicated that the trees began to provide significantbenefits to their crops in 1 to 3 years. Another 43% relatedthat it took 4 to 6 years before they observed the benefitsof planting Faidherbia (Phombeya 1999). However,establishing Faidherbia does not preclude planting othernitrogen-fixing trees in the same fields that have a moreimmediate impact on soil fertility and crop yields (see nextsection).

The Zambia Agroforestry Project of The World Agrofor-estry Centre has contributed significantly to the research anddevelopment of Evergreen Agriculture practices in Zambiaand southern Africa. The maize agroforestry technologiesdeveloped include leguminous tree improved fallows.Research on improved fallows began in the late 1980s, andreceived growing attention in the mid-1990s in Zambia(Mafongoya et al. 2006), following the articulation ofbiological approaches to soil fertility management (Sanchez1994). Investigations on the performance of rotationalfallows of Sesbania sesban, Tephrosia vogelii, Tephrosiacandida, pigeon peas (Cajanus cajan) and Crotalaria spp.have shown that after a 2–3 year fallow, these shrubs provide100–250 kg of nitrogen per hectare, enhancing the yields ofthe maize crops that follow (Kwesiga and Coe 1994;Mafongoya et al. 2006). Trials across farmers’ fields withmaize grown after 2 years of Sesbania showed that the yieldsof unfertilized maize were less than 1 t/ha, while the majorityof farmers with improved fallows had yields of more than4 t/ha (Kwesiga et al. 2003). In addition, improved fallowsprovide abundant fuel energy for rural households. Between15 and 21 t/ha of fuel wood were harvested after 2- and3-year fallows of Sesbania, respectively (Kwesiga andCoe 1994).

Research on the intercropping of maize with thecoppicing legumes Gliricidia sepium, Leucaena leucoce-phala, Calliandra calothyrsus, Senna siamea and Flemin-gia macrophylla has also been on-going for over a decadein eastern Zambia. In contrast to the short-rotation fallows,intercropping with coppicing species increases grain yieldscontinuously for many years after their establishment. Theadditional organic inputs are derived each year from thefoliage re-growth that is cut and applied to the soil. Resultsof long-term experiments established in the early 1990sshow significant improvement in soil fertility and maizeyields (Sileshi and Mafongoya 2006).

The disadvantage of the short-term improved fallowsystems is that land is taken out of production for 2 out ofevery 5 years. Nevertheless, they provide greater aggregatecrop production and higher returns on investment than thecontinuous cropping of unfertilized maize, the farmers’ defacto practice (Ajayi et al. 2009). Over a 5-year cycle, thenet profit from unfertilized maize was US$130/ha com-pared to US$$269 and US$309/ha for maize grown as anintercrop with Gliricidia or in rotation with Sesbania,respectively. The agroforestry practices had a benefit to costratio (BCR) ranging between 2.77 to 3.13 in contrast to2.65 with subsidized fertilizer applications, 1.77 in fieldswith non-subsidized fertilizer, and 2.01 in non-fertilizedfields (Ajayi et al. 2009).

One way to assess impact is in terms of food security bydetermining the number of days of additional food that thepractices provide to a household. Assuming an averagefallow plot area of 0.20 ha, these systems generate between57 and 114 extra person days of maize consumption peryear (Ajayi et al. 2007). An initial investment in terms ofhigher labour is involved when farmers move fromconventional to Evergreen Agriculture models, but oncefarmers gain experience with them they manage labour usemore efficiently (Tripp 2005). Through learning-by-doing,farmers in eastern Zambia have adapted official recom-mendations and made innovations with improved fallowpractices. Such innovations include the use of bare-rootedseedlings instead of bagged seedlings, combinations ofmore than one fertilizer tree species, and pruning Gliricidiaconcurrently with weeding. Details of these innovationshave been documented by Katanga et al. (2007).

There is evidence that the integration of fertilizer treesinto smallholder maize production in Zambia, alone or incombination with conservation farming practices, hasresulted in greater productivity, food security, and familyincome. These practices are, however, knowledge-intensiveas opposed to being cash-intensive. Thus, sustained ruraladvisory services, through the public sector and privatesector, are important to ensuring sustained uptake andexpansion over the longer term (Kwesiga et al. 2005; Ajayiet al. 2005; Place et al. 2005).

Maize agroforestry in Malawi

The Malawi economy is heavily dependent on agriculture,which contributes 35% to the GDP, and, employs 78% ofthe national labor force (Republic of Malawi 2008). Ninety-percent of national export earnings come from the sector.Almost all maize is grown under rain fed agriculture duringthe single rainy season from November to April. The cropis subject to rainfall variability that can be particularlydamaging when dry spells occur. Decades of intensive

202 D.P. Garrity et al. Author's personal copy

cultivation by smallholders, in the absence of significantfertilizer use, have depleted the soils of nutrients, particu-larly nitrogen (Sanchez 2002; Carr 1997). National yieldsof maize have averaged 1.3 t/ha during the past twodecades (Denning et al. 2009; Food and AgricultureOrganization of the United Nations 2008).

Over half of Malawi’s farm households operate belowsubsistence. Only 20% of maize farmers produce a surplusand sell some of their product, due to low productivity andsmall farm size. As a result, most households must purchasemaize at much higher prices when stocks are exhausted,typically during January to March (Republic of Malawi2008). During the 2004–2005 maize-growing season,drought had a devastating effect on yields: the nationalaverage that year was 0.76 t/ha, 40% below the long-termaverage. In November 2005, five million Malawians, 38%of the population, needed food aid (Famine Early WarningSystems Network 2007). These circumstances underscorethe urgent need to improve smallholder maize productivityand make it more resilient to drought stress.

In the face of this crisis, the Government launched aprogramme to subsidize agricultural inputs, using discre-tionary budget funds to import fertilizer and procureimproved maize seed for distribution to farmers. The costof the maize subsidy in 2005–2006 was estimated atapproximately US$50 million (Denning et al. 2009). Theresult was a harvest estimated at 3.44 million tonnes, an all-time national record for Malawi, generating a surplus ofabout 1.34 million tonnes of maize grain above nationalrequirements.

The key issue now is how to ensure sustained growth inmaize production to prepare for the medium-term situationwhen fertilizer subsidies may have to be scaled back orwithdrawn. Agroforestry systems, through the use ofnitrogen-fixing trees, are providing options in Malawi thatcomplement and reduce the need for inorganic nitrogenfertilizer. There is a long history of research on suitablefertilizer tree practices in Malawi and in the neighboringcountries in Southern Africa (Sileshi et al. 2008). Cultiva-tion of crops under Faidherbia albida has been traditionallypracticed in Malawi for generations within systems thatevolved under smallholder farmers’ environmental andsocio-economic conditions. Traditionally, some Malawianfarmers grew their crops under scattered trees of Faidherbiaalbida (Rhoades 1995).

Formal research on the tree began in Malawi in the 1980swhere it was carried out as part of the activities of theAgroforestry Commodity Team under the Government’sDepartment of Agricultural Research and Technical Services(DARTS). Saka et al. (1994) reported 100–400% yieldincreases of maize under Faidherbia trees in the Lakeshoreplain of Malawi. Several agencies have been promoting itscultivation in Malawi for the last two decades (Akinnifesi et

al. 2008). It is estimated that currently about 500,000Malawian farmers have Faidherbia trees on their farms(Phombeya 2009). The majority of these stands weredeveloped through assisted natural regeneration of seedlingsthat emerged in farmers’ fields (Fig. 3).

Since the early 1990s, the World Agroforestry Centre andits partners in eastern and southern Africa have beendeveloping a range of agroforestry systems that wouldimprove soil quality and significantly boost crop yields,providing high returns on both land and labour. The mostpopular system in southern Malawi, where landholdings arevery small (<0.5 ha), is intercropping maize with nitrogen-fixing tree species of Gliricidia sepium, Sesbania sesban,Tephrosia species and pigeon peas. Sesbania sesban,Tephrosia (T. vogelii and T. candida) and pigeon peas areoften relay-intercropped with maize (Snapp et al. 1998;Akinnifesi et al. 2008). In these systems, farmers plant thetrees in rows between their crops. Gliricidia is pruned backtwo or three times a year, and the leafy biomass isincorporated into the soil (Fig. 3). A long-term experimentspanning more than a decade, involving the continuous

Fig. 3 Two promising fertilizer tree systems in Malawi: a) Faidherbiatrees intercropped with maize, and b) Gliricidia managed as a coppiceshrub in maize fields Photos: D Garrity

Evergreen Agriculture: sustainable food security in Africa 203 Author's personal copy

cultivation of maize with Gliricidia at Makoka ResearchStation, Malawi, yielded more than 5 t/ha in good years,and an average of 3.7 t/ha overall, in the absence ofmineral fertilizers: that compared with an average of 0.5–1.0 t/ha in control plots without Gliricidia or mineralfertilizer (Akinnifesi et al. 2007; Makumba et al. 2006).

Rotational fallows that incorporate nitrogen-fixing treesare also suited to areas where land holdings are somewhatlarger (>1 ha). In this case, during the fallow period farmersgrow short-lived shrubs such as Sesbania sesban andTephrosia candida, rather than the long-lived, intercroppedtrees like Gliricidia. Rotational fallows of Sesbania sesbanand Tephrosia candida have been widely tested in farmerparticipatory research in Malawi. Results from 152 farmsshow that agroforestry increased the yield of maize by 54–76% compared to unfertilized sole maize, which is the defacto farmer practice (Akinnifesi et al. 2009). Whensupplemented with inorganic fertilizer, the yield increaseover the control was 73–76% across tree species (Akinnifesiet al. 2009)..

In addition to increasing soil fertility and crop yields,these agroforestry systems were observed to suppressweeds (Sileshi et al. 2006), improve water filtration(Chirwa et al. 2007), and increase the amount of soilcarbon (Makumba et al. 2007). There is evidence thatproduction systems that incorporate Gliricidia, Tephrosia,Faidherbia and other leguminous cover crops assist ruralpopulations to adapt their agriculture to the adverse effectsof climate change. Research results and farmer interviewsindicated that these systems increased the grain harvestduring serious droughts (Akinnifesi et al. 2010; Sileshi etal. 2010). Farmers obtained at least a modest yield duringseasons when farmers not using these practices experiencedcrop failure.

Malawi launched an Agroforestry Food SecurityProgramme in 2007 based on these results. The programmeis managed by the World Agroforestry Centre, the Ministry ofAgriculture, the Malawian Farmers’ Association (NASFAM),and a number of NGOs. It provides tree seeds, nurserymaterials, and training for a range of agroforestry species,including fertilizer trees. By mid-2009, over 120,000 farmershad received training and tree materials from the programme.Support from the Government of Ireland has now enabled theprogramme to expand nationally to 40% of Malawi’s districts,involving at least 200,000 families or around 1.3 million of thepoorest people.

Malawi’s Agroforestry Food Security Programme is alsoincorporating a diverse range of fruit, timber, fuel wood,and tree cash crops into maize farming systems to enhanceenterprise diversity and income generation. It relies onwhole-village mobilization, particularly through farmer andwomen’s groups, to accomplish the scale of action targeted.Women and the rural poor are the major beneficiaries. The

poor are often observed to adopt agroforestry systems morerapidly than wealthier households (Ajayi et al., 2005; Placeet al., 2005; Pye-Smith 2008).

The Malawi Agroforestry Food Security Programme isassisting the uptake of tree types of nitrogen-fixing treelegumes: short-term species such as Tephrosia candida,Sesbania sesban, and pigeon peas, which are planted andincorporated within 1 year; medium-term solutions such asGliricidia, which can be continuously pruned for organicfertilizer for 1 to 2 decades; and long-term full canopy treesof Faidherbia albida, which provide benefits for manydecades. These species are often combined in the samefields. The optimum combinations are being tailored to therange of variation in agroecological conditions and farmcircumstances across the country.

Research to date has indicated that such forms ofEvergreen Agriculture may generally increase yields from1 t/ha to 2–3 t/ha, even if farmers cannot afford commercialnitrogen fertilizers. However, with an application of aquarter-dose of mineral fertilizer, maize yields may surpass4 t/ha (Akinnifesi et al. 2010; Sileshi et al. 2010).

A current opportunity is to link fertilizer subsidiesdirectly to agroforestry investments on the farm in orderto provide for long-term sustainability in nutrient supply,and to build up soil health as the basis for sustained yieldsand improved efficiency of fertilizer response. This can bedone in the short-term by combining the provision oflimited amounts of subsidized fertilizer with the provisionof seed and technical advice to establish fertilizer treesystems. Farmers can thus be further encouraged to producemore of the nitrogen required by their crops on farm,increasing and sustaining their maize yields and improvingtheir soils. This would foster a gradual shift of investmentsfrom fertilizer subsidies to sustainable on-farm fertilityregeneration. Discussions are underway with the Governmentof Malawi to map out such a ‘subsidy to sustainability’pathway.

Niger: The case of farmer-managed tree regeneration

The Sahel is the belt of land that stretches across Africa onthe southern edge of the Sahara Desert. It is one of thepoorest regions in the world, and has long been plagued bydroughts. Throughout the Sahel, farmers have for manygenerations maintained a traditional land-use system knownas the agroforestry parklands (Boffa, 1999). It is characterizedby the deliberate retention of trees on cultivated land. Thetrees are an integral part of the agricultural system, providingfood, fuel, fodder, medicinals, wood for buildings, cashcommodities, as well as contributing to soil fertility, waterconservation, and environmental protection. Demographic,economic, environmental and social developments during

204 D.P. Garrity et al. Author's personal copy

the past 40 years have put pressure on traditional land-usesystems. Modern Sahelian forest laws, and the ways thatthey are locally enforced, have discouraged farmers fromoptimum parkland management and led to the degradation ofthe parklands to a varying extent across the region (Boffa,1999). This was particularly the case in Niger.

Nigerien farmers had managed their agricultural parklandsand village woodlands to produce a continuous harvest oftrees and tree products for centuries (Boffa 1999). However,during the 1970s and 1980s they faced massive tree lossesfrom drought and human population pressures, resulting inwidespread desertification of the agricultural landscape.Considerable efforts were made to re-establish the vanishingtree cover through conventional reforestation projects.However, these overwhelmingly failed due to the harshenvironment and a lack of attention given to the species thatfarmers preferred, and their reasons for nurturing them ontheir farms (Tougiani et al. 2009).

Traditionally, farmers had sustained populations of 10–50trees/ha on their farms, not by planting them, but rather byobserving the seedlings of useful species and allowing themto regenerate naturally in their fields. This practice is knownas assisted natural regeneration (ANR), or farmer-managednatural regeneration (FMNR). Its success is due to theobservation that seeds of useful trees are constantly beingdistributed by cattle, goats, birds, and wildlife throughout theagricultural environment. Likewise, underneath farmers’cleared fields lay extensive webs of living tree roots andstumps that were continually throwing up new stems. Theseare an invaluable source of new tree stock.

During the mid-1980s, development projects began toemphasize FMNR as a way to re-establish useful trees inthe desertified agroecosystems of southern Niger (Tougianiet al. 2009). Farmers would prune the selected stems topromote their growth and the production of food, fuel, orfodder, while removing new, competing stems as needed.Periodically, they would harvest one of the original stemsand choose a newly sprouting stem as a replacement, whilegrowing their food crops between the trees. The techniqueswere flexible, and farmers adapted them to their ownsituations and objectives. They generated a range ofbenefits. The trees produced a supply of dry-season fodderfor livestock, and they provided firewood, fruit, andmedicinal products that farm households could consumeor sell. Moreover, Faidherbia albida, one of the mostubiquitous species, enhances fertility by adding nitrogen tothe soil (Barnes and Fagg 2003).

The re-greening process in central Niger began when anNGO in the Maradi region initiated a pilot project providingfood aid to farmers willing to protect natural regeneration(Tougiani et al. 2009). The practices spread through widersupport by other projects. Understanding of the processes,and wider awareness, was further enhanced by research

collaboration between the University of Niamey and theWorld Agroforestry Centre. An evolving coalition of local,national, and international actors is now further enablinglarge-scale diffusion and continued use of these improvedpractices. Interest in Faidherbia and FMNR was furtherstimulated in the 1990s when the successful experiences ofseveral pilot projects were shared with government policy-makers. This encouraged the government to relax therestrictive forestry regulations (Code forestier) that hadseverely limited farmer management of their own trees.Farmers were no longer prohibited from cutting down treeson their own farms or fined for pruning their trees. They nowhad an incentive to farm more intensively with Faidherbiaand other trees, which they could also cut for timber and fuelwood sales (Dramé and Berti 2008). As a result, communitiesdramatically increased their efforts to regenerate and expandthe tree populations on their farms. Farmer-managed naturalregeneration of Faidherbia and other tree species began toaccelerate rapidly. In 2004, the Government of Niger formallyrecognized this trend by revising the national forestry laws toeliminate the onerous restrictions on the freedom of farmersto manage the trees that they sustained on their own land.This further accelerated the process of FMNR and extensivetree culture on farmland.

Tree densities and tree cover in Niger have increasedover time. Analysis of high-resolution images acquiredduring 2003 to 2008 show that in the Maradi and ZinderRegions of Niger there are now about 4.8 million hectaresof Faidherbia-dominated farmlands generated throughFMNR (Reij et al. 2009). These landscapes harborpopulations of Faidherbia of up to 160 trees per hectare(Fig. 4 and 5). Many villages now have 10–20 times moretrees than 20 years ago. In 2005–06, a team of researchersfrom Niger examined the impacts of investments in naturalresource management and long-term trends in agricultureand the environment (Adam et al. 2006). The highest treedensities were found in areas of high rural populationdensity. Moreover, many of the trees were young and, thus,

Fig. 4 High-density Faidherbia tree intercropping in millet systemsin southern Zinder, Niger, dry season, 2006. Photo: M Larwanou

Evergreen Agriculture: sustainable food security in Africa 205 Author's personal copy

still increasing in size and ground cover. Today, theagricultural landscapes of southern Niger have considerablymore tree cover than they did 30 years ago (Reij et al.2009). Vast expanses of savanna devoid of vegetation in theearly 1980s are now densely studded by trees, shrubs, andcrops (WRI 2008).

Reij et al. (2009) estimated that this transformation hasresulted in an average of at least 500,000 additional tonnesof food produced per year. This additional productioncovers the requirements of 2.5 million people out of a totalpopulation of about 15 million in 2009. Despite a near-doubling of the population since 1980, Niger has been ableto maintain per capita production of millet and sorghum,which make up more than 90% of the typical villager’s diet.Per capita production remained at approximately 285 kgbetween 1980 and 2006. FMNR has also had an indirectimpact on food security through the tree products thatfarmers harvest and sell in local markets, particularly fuelwood and timber (Dramé and Berti 2008). In recent years, thechanged landscape has also been critical in managing crises.Between 2004 and 2006, when much of Niger was facing afood crisis caused by drought compounded by other factors,including the export of cereals to the urban markets ofnorthern Nigeria, villages that had protected and managednatural regeneration were much less affected by the foodshortages than villages that had not (Reij et al. 2009).

Millet and sorghum production in combination withFaidherbia in these areas is accompanied by non-inversiontillage methods. The majority of Nigerien farmers do not usethe plow or the hoe for land preparation on their typicallysandy soils. Rather they use a hand tool for loosening thesoil and undercutting weeds, that is passed just underneaththe soil surface without inverting the soil. Thus, Nigerienagriculture is essentially already integrating agroforestry intoa minimum tillage conservation farming system. Nigerfarmers claim that the trees improve their crop yields, and

also relate that the foliage and pods provide much-neededfodder for their cattle and goats during the long Sahelian dryseason. Larwanou et al. (2006) interviewed about 400farmers in the Zinder Region individually and in groupsabout their FMNR practices. According to the farmersinterviewed, the trees reduce wind speed and evaporation.In the 1980s, crops had to be replanted three or four timesbecause they were covered by wind-blown sand, but todayfarmers typically plant only once. Nitrogen-fixing specieslike Faidherbia albida enhance soil fertility, although farm-ers do not observe these effects with very young trees.

The most common species regenerating naturally andprotected by farmers in Niger include Faidherbia albida(known as gao in Niger), Combretum glutinosum, Guierasenegalensis, Piliostigma reticulatum, and Bauhinia rufes-cens. Depending on the location of the village, other speciescan be important, such as Adansonia digitata (baobab) andProsopis africana. Sahelian women have benefited in thatFMNR has greatly improved the supply of fuel wood over thepast 20 to 30 years, allowing them to reallocate the time oncespent on collecting fuelwood to other activities, includingproducing and preparing food and caring for children.

No study has systematically quantified the impacts ofFMNR, but Larwanou and Adam (2008) have made a stepin this direction. They calculated that if the number of treeshas increased by 40 trees/ha (trees of all ages) on a scale of5 million ha, then FMNR has added about 200 million newtrees to Niger’s tree stock (Reij et al. 2009). Larwanou andAdam (2008) assumed that every tree produces an averagevalue of $1.40 per year in the form of improved soilfertility, fodder, fruit, firewood and other produce. Thiswould mean an additional value of at least $56/ha/year, anda total annual production value of $280 million.

Wider research and experience with Faidherbia

Investigations on the properties of Faidherbia began over60 years ago, when scientists observed that farmersthroughout the Sahelian region of Africa were retainingthe trees in their sorghum and millet fields (Barnes andFagg 2003). The species has long been an integral part ofSahelian agriculture, where farmers have nurtured andprotected the trees growing in their fields for centuries.The trees are a frequent component of the farming systemsof Senegal, Mali, Burkina Faso, Niger, Chad, Sudan, andEthiopia, and in parts of northern Ghana, northern Nigeria,and northern Cameroon (Boffa 1999). There are manyreports of dramatic increases in the grain yield ofunfertilized millet grown under Faidherbia in West Africa(Barnes and Fagg 2003). Increases in yield have also beenreported for sorghum grown under Faidherbia in variousparts of Ethiopia, other parts of Africa, and in India. Often,millet and sorghum exhibit no further response to artificial

Fig. 5 Millet production landscapes within Faidherbia parklands inNiger: a transformed agricultural system. Dry season after milletharvest. Photo: M Larwanou

206 D.P. Garrity et al. Author's personal copy

fertilizers beyond that provided by the leaf fall (Barnes andFagg 2003). Other crops that are reported to benefit fromassociation with Faidherbia include groundnuts and cotton.Rhoades (1995) reviewed several results in Africa andreported yield increases of 37% for groundnut, and 200%for sorghum in the north-central Senegal, and 115% forsorghum in Burkina Faso. Faidherbia has also beencultivated traditionally by farmers in various parts ofEthiopia, where it enhances cereal production up to 2800meters elevation in Tigray Province (Hadgu 2008). Thereare many questions still to be answered about how to fullyexploit the value of this unique agroforestry tree, and howto avoid the use of the species where it might causeunforeseen problems.

Boffa (1999) reviewed research conducted in variouscountries on the improvement of soil nutrient content andcrop yields under Faidherbia albida canopies, comparedwith controls in the open. Increases in nitrogen contentranged from 15 to 156%, but significant increases were alsofound in carbon, phosphorus, exchangeable potassium,calcium, and magnesium. The impact on millet yieldsranged from 49 to 153% increases; for sorghum, most yieldincreases ranged from 36 to 169%. In absolute terms, thismeans, in most cases, an additional cereal yield of 400–500 kg/ha or more. This may explain why farmers in parts ofthe densely populated southern Zinder Region have createdsuch a high-density agroforest of Faidherbia albida.

Encouraged by the experience in Niger, new pro-grammes to promote farmer-managed natural regenerationwith Faidherbia and other species have been established inother countries across the Sahel. Recently, these effortshave coalesced into the launch of the African RegreeningInitiative, an alliance of organizations that seeks to promoteawareness and action to multiply and intensify the dramaticsuccesses achieved in Niger (http://www.cis.vu.nl/projects).The work is encouraging more optimal tree densities inareas where agroforestry is already practiced, and propa-gating the trees in areas where parkland farming systemsare not present. This is further enhanced by new knowledgeof simple, effective propagation techniques for Faidherbiaand other species that farmers can use locally (CFU).Farmers in many areas relate that they have been constrainedby lack of practical methods to produce their own seedlingsof Faidherbia and successfully establish them in their cropfields. This knowledge gap has now been overcome.

Burkina Faso: adaptation of conservation farmingin an extreme environment

The 1968–73 Sahelian droughts caused an acute human andenvironmental crisis in Burkina Faso, a Sahelian country

adjacent to Niger. The densely populated Yatenga Provinceon the northern Central Plateau of Burkina Faso wasparticularly affected. Failure of the agricultural systemsprompted massive labor migration and caused socialdisruption (Monimart 1989). Between 1975 and 1985,some villages lost up to 25% of their population as theymigrated south to areas of higher rainfall. In the early1980s, groundwater levels in the Central Plateau droppedan estimated 0.5–1.0 m per year (Reij 1983). Many wellsand boreholes went dry just after the end of the rainyseason and had to be deepened.

Average sorghum and millet yields decreased to slightlybelow 300 kg/ha (Matlon and Spencer 1984; Matlon 1990).As a result, the majority of farm households had annual fooddeficits of 50% or more (Broekhuyse 1983). Most land wascultivated continuously on shallow lateritic, crusting soilswith very low natural fertility, creating extensive areas ofbarren, unusable land. As the landscape became denudedand exposed to severe water erosion, the land and the peoplebecame increasingly vulnerable to drought.

During the 1980s, farmers began experimenting withtraditional techniques to reclaim severely degraded farm-land that water could not penetrate. They developedvariations of the practice of digging a grid of planting pits(zaï) across their fields. The depth and diameter of the pitswas increased, and organic matter added to the basins toregenerate an environment where plants could grow. Thepits concentrated nutrients in the plant root zone, andretained water for extended periods of time, allowing cropsto better survive dry spells. The pits are prepared during thedry season, enabling early planting for increased yields.The use of new and improved planting pits spread rapidlyamong farmers with the support of NGOs and the extensionservice. Another practice that became popular with farmerswas the construction of contour stone bunds that reducesurface runoff from the fields.

By 2001, well over 100,000 ha of badly degraded landhad been rehabilitated by projects and by farmers on thenorthern part of the Central Plateau alone (Reij andThiombiano 2003). Taking into account what has beenachieved in this region since then and on other parts of theCentral Plateau, it is now estimated that the total arearehabilitated over the past three decades is somewherebetween 200,000 and 300,000 ha (Kaboré and C. Reij(2004), Botoni and Reij 2009; Reij et al. 2009). A recentstudy shows that in villages with a long history of soil andwater conservation, 72 to 94% of the cultivated land hasbeen rehabilitated with one or more conservation techni-ques. In villages with a shorter history, this figure rangesfrom 9 to 43% (Reij et al. 2009).

Cereal production is estimated to have increased by anaverage of at least 400 kg/ha, a percentage increase of 40%to more than 100% (Reij et al. 2009). This translates into an

Evergreen Agriculture: sustainable food security in Africa 207 Author's personal copy

annual increase of 80,000 tonnes of grain, enough toprovide for 500,000 people. Zaï planting pits alone usuallyhave a greater impact on yields than stone bunds alone, butthe greatest returns accrue from using both together. Theeffect of the practices was synergistic with added manure.With these increases, farm households that suffered fromfood deficits of 6 months or more in a year during the early1980s have been able to reduce their deficit periods to 2–3 months, or to zero in some cases (Reij et al. 2009).

The zai planting pits have been used to intensify cerealproduction as well as to produce trees, or to combine cerealand tree production in agroforestry systems. By stimulatingtree production in combination with planting pits, biomassproduction is dramatically increased, for soil ameliorationas well as livestock fodder (Reij et al., 2009). On theCentral Plateau, rehabilitated fields now average 126 treesper hectare, compared with 103 trees per hectare on controlplots. The trees on rehabilitated land are larger andrepresent a wider range of species. These modifiedtraditional agroforestry-, water-, and soil-managementpractices have transformed barren agricultural landscapesinto complex agricultural systems with more vegetation andmore varied vegetation (Reij et al. 2009).

Some common indigenous tree species, such as Com-bretum glutinosum and Piliostigma reticulatum, can bemanaged as coppiced stumps at a density of at least severalhundred per hectare, under a management system much likethe coppiced trees of Gliricidia that are integrated intomaize systems in Malawi (see previous section). If alsocombined with full-canopy Faidherbia trees, several tonnesof additional biomass can be generated annually per hectareto accelerate soil fertility replenishment, provide additionallivestock fodder, and increase yields. These developmentshave also brought changes in how rural people earn theirlivelihoods. After the harvest, men once commonlymigrated to urban areas for employment, but someindicators suggest that this pattern is changing as moremen remain in the villages because they can now earnsufficient incomes from agriculture.

Current research with Burkinabe farmers on theseoptions holds the promise of further increasing ecosystemproductivity and land rehabilitation in Burkina Faso. Thespread of the zaï technique may be accelerated as scientistsfrom Institut de l’Environnement et de Recherches Agri-coles (INERA) of Burkina Faso have developed a 'mechan-ical zaï' that consists of making the pits mechanically withanimal-drawn tools. This reduces by more than 90% theamount of time required for making the pits (Barro et al.2005). Efforts to adapt and expand these EvergreenAgriculture systems to the western and southern areas ofBurkina Faso are now accelerating through the AfricanRegreening Initiative, and through projects involvingNGOs such as Catholic Relief Services. These are

augmented by the research and capacity-building pro-grammes of the World Agroforestry Centre, the AfricanConservation Tillage Network, the Food and AgricultureOrganization of the United Nations and others. The nextstage is anticipated to be a full-scale national programmethat will bring together the various efforts into acoordinated campaign throughout the country.

The future of Evergreen Agriculture in Africa

The previous sections reviewed significant advances in theapplication of the principles and practices of EvergreenAgriculture at a major scale in southern and western Africa.The advances in Malawi and Niger are particularlynoteworthy as these countries have suffered mass mortalityfood crises since 2000 (Devereux 2009). In these areas,where smallholder livelihoods are undiversified, and aredominated by subsistence-oriented food crop production,even a moderate decline in harvests can be devastating forhousehold food security (as in Malawi in 2001–2002 andNiger in 2004–2005). Climate change is likely to make thissituation worse, with declining and/or more erratic rainfallresulting in lower aggregate production and more unpre-dictable harvests in much of Africa (Funk and Brown2009).

The farming practices embodying the principles ofEvergreen Agriculture are unique to each country, but theyexhibit important similarities. Each involves the integrationof tree species into food crop farming in ways that increaseand sustain grain production, and diversify and increasehousehold income. The trees sustain a green cover on theland resulting in higher biomass production that contributesto enhanced soil fertility and increased fodder production.And they have enabled practical ways of reducing soiltillage to improve rainwater-use efficiency, increase soil-carbon accumulation, and improve soil health. In eachnational case there is evidence that the practices increasedhousehold and national food security, and that they havereached a level of adoption that may be sustainable in thelong term with adequate farm advisory support. Further,there is evidence in all four cases that governments aredeepening their support for the expansion of theseEvergreen Agriculture systems throughout their territories.

The experiences of Zambia, Malawi, Niger, and BurkinaFaso indicate that the principles of Evergreen Agriculturemay be applicable to a much broader range of food cropsystems in Africa, if accompanied by adequate research andfarmer engagement. Although these countries may be themost advanced large-scale examples of Evergreen Agricul-ture on the continent, there are also successful examples inmany other countries, although many of these are at a morelocalized scale.

208 D.P. Garrity et al. Author's personal copy

The success of Evergreen Agriculture has promptedvigorous political action at the continental level. In April2009, at a meeting organized by the African Union in AddisAbaba, theMinisters of Agriculture, Land and Livestock fromacross the continent published a declaration that committedthem to ramping up efforts to increase the number of farmerspracticing agroforestry-based conservation agriculture, andthey called for increased international support for these efforts.Subsequently, the African Ministers of Environment alsoendorsed this recommendation during their meeting in Nairobiin May, 2009.

The Comprehensive African Agricultural DevelopmentProgramme (CAADP) is now recognized as the mechanismfor coordinating international and national efforts to spuragricultural growth in Africa. The African Union’s NewPartnership for Africa’s Development (NEPAD) is chargedwith the development and implementation of a nested set ofaction plans under CAADP. NEPAD is now finalizing aCAADP Framework for Climate Change and Agriculture tocoordinate programmes to link productivity increases withinvestments, to adapt African agriculture to climate change,and to contribute to the mitigation of carbon emissions.NEPAD has called for a continental effort on EvergreenAgriculture as a flagship programme to address thesechallenges.

A broad alliance is emerging of governments, interna-tional donors, research institutions, and international andlocal development partners, in order to expand EvergreenAgriculture throughout Africa. The World AgroforestryCentre, the African Conservation Tillage Network, theZambian Conservation Farming Unit, and CILSS1 havebeen asked by NEPAD to work closely with other researchand development partners, and a growing consortium ofsupportive donors to develop the evidence base and thecapacity on the ground to ensure that this vision becomes areality. The regional economic commissions of COMESA2,ECOWAS3, and the EAC4 have been encouraged toactively engage in using their influence to further acceleratethis process. For example, COMESAwill be investing over$50 million in agroforestry-based conservation farmingduring the next 5 years, with support from the Governmentof Norway.

Tanzania and Kenya have recently developed nationalstrategies and work plans to support the expansion ofEvergreen Agriculture, drawing on the expertise of theAfrican Conservation Tillage Network, FAO and the WorldAgroforestry Centre. National alliances are now also being

created in Ethiopia, Rwanda, Ghana, Mali, and a number ofother countries to develop their own Evergreen Agricultureprogrammes, building on the experience of Malawi,Zambia, Niger, and Burkina Faso. And the AfricanRegreening Initiative is spearheading the expansion ofassisted natural regeneration in the Sahelian zone. Thedonor community is mobilizing to support these efforts on amuch greater and more coordinated scale under theCAADP Framework for Climate Change and Agriculture.

Evergreen Agriculture and climate change

As Lal (2010) has pointed out, addressing the issue of food-insecurity and global warming through the sequestration ofcarbon in soils and the biota, along with payments toresource-poor farmers for the ecosystem services rendered,would be a timely win-win strategy. Conventional conser-vation farming systems tend to sequester a maximum of0.2–0.4 t C ha−1yr−1. Evergreen Agriculture systemsaccumulate carbon both above and below-ground in therange of 2–4 t C ha−1yr−1, roughly an order of magnitudehigher than with conservation farming alone. This isparticularly true for systems incorporating fertilizer treessuch as Faidherbia or Gliricidia (Makumba et al. 2007;Kaonga and Bayliss-Smith 2008). Consequently, there isconsiderable interest in the creation of bio-carbon invest-ment funds in Africa to channel carbon offset paymentsfrom developed countries to stimulate more carbon seques-tration in African food crop systems while simultaneouslyenhancing the livelihoods of smallholders and the environ-ment. These investments will encourage developmentpathways resulting in higher carbon stocks at a wholelandscape scale (Garrity and Verchot 2008).

Most forest conversion to agricultural land in Africa is dueto clearing by subsistence farmers. A sustained elevation insmallholder crop productivity through the expansion ofEvergreen Agriculture can result in significant co-benefits byproviding a basis for reducing the overall rate of deforestationon the continent. The new bio-carbon investment funds, iffocused on Evergreen Agriculture, could provide new resour-ces to expand farmers’ capacity to contribute to the reductionof global carbon emissions while growing more food andproviding other sustainable development benefits. Such invest-ments will assist smallholder food crop agriculture to becomemore resilient to adverse climate change by reducing yieldlosses due to drought (Syampungani et al. 2010; Neufeldt etal. 2009; Garrity and Verchot, 2008; Kandji et al. 2006).

Conclusion

Today, Africa is critically threatened by food insecurity, landdegradation, and climate change. Smallholder farmers need4 The East African Community

1 Comité Inter-Etate pour la Lutte contre la Sécheresse au Sahel2 Common Market for Eastern & Southern Africa3 The Economic Community Of West African States

Evergreen Agriculture: sustainable food security in Africa 209 Author's personal copy

science-based solutions to increase the efficiency of their cropproduction systems: solutions that build on the best of localknowledge and practice, and that are accessible and affordable.Evergreen Agriculture embodies new options to better care forthe land and to increase smallholder food production. However,the effective targeting of investments to expand EvergreenAgriculture needs to be based on a scientific assessment of landdegradation hot spots in each country. The past several yearshave seen enormous advances in spectroscopic methods forrapid, low cost, high throughput soil and plant analysis(Shepherd and Walsh 2007; Swift and Shepherd 2007). Thesedevelopments are now being harnessed through the newAfrican Soil Information Service (AfSIS) to enable science-based diagnostic surveillance approaches to agricultural andenvironmental management on a continental scale.

The recent food price crisis has reawakened worldleaders and donor agencies to the necessity of assuringthe food security of all nations, and to revitalizing andreinvesting in the agriculture sector. Such investments areurgently needed to promote agricultural growth and reducepoverty. Most African governments have not yet prioritizedsupport for the agricultural sector. And farmers in manyparts of the continent (but not all) have remained poorlyorganized, and have failed to lobby effectively for anadequate share of public resources. Sustained engagementwith these stakeholders is required to unlock the potentialof Evergreen Agriculture to transform the lives of largenumbers of poor households in rural communities acrossthe continent, and to make significant contributions toalleviating the effects of climate change.

Acknowledgement The authors gratefully acknowledge the finan-cial and in-kind support provided for this work by the Governments ofMalawi, Zambia, Niger and Burkina Faso, the Governments ofAustralia, Canada, Denmark, Finland, Germany, Ireland, Japan,Norway, Sweden, United Kingdom, and the United States, by theInternational Fund for Agricultural Development, and by the Rock-efeller and Bill and Melinda Gates Foundation.

For updated current information World Agroforestry Centre website: http://www.worldagroforestry.org/af/index.phpAfrican Conservation Tillage Network web site: http://www.act.org.zw/Conservation Farming Unit web site: http://www.conservationagriculture.org/

References

Aagard, P. (2009). Conservation Farming Unit, Lusaka, Zambia.Personal communication

Abdulai, A., Barret, C. B. Hazell, P. (2004). Food aid for marketdevelopment in sub-Saharan Africa. DSGD discussion paper No. 5.Development Strategy and Governance Division International FoodPolicy Research Institute (IFPRI). Washington, D.C. 20006 U.S.A.56 p.

Adam, T., Abdoulaye, T., Larwanou, M., Yamba, B., Reij, C., Tappan,G. (2006). Plus de gens, plus d’arbres: La transformation des

systèmes de production au Niger et les impacts des investisse-ments dans la gestion des ressources naturelles. Rapport deSynthèse Etude Sahel Niger. Comité Permanent Inter-Etats deLutte contre la Sécheresse dans le Sahel and Université deNiamey, Niamey

Ahmed, A., Hill, I., Smith, D., Wisemann, D., Frankernburger, T.(2007). The World’s Most Deprived: Characteristics and causesof extreme hunger and poverty (2020) Discussion Paper 43.International Food Policy Research Institute, Washington

Ajayi OC, Place F, Kwesiga P, Mafongoya Franzel S (2005) Impact ofFertilizer Tree Fallows in Eastern Zambia. World AgroforestryCentre, Nairobi, p 28

Ajayi OC, Place F, Kwesiga F, Mafongoya P (2007) Impacts ofImproved Tree Fallow Technology in Zambia. In: Waibel H,Zilberman D (eds) International Research on Natural ResourceManagement: advances in impact assessment CABI Wallingford.UK and Science Council/CGIAR, Rome, pp 147–168

Ajayi CO, Akinnifesi FK, Sileshi G, Kanjipite W (2009) Labourinputs and financial profitability of conventional andagroforestry-based soil fertility management practices in Zambia.Agrekon 48:246–292

Akinnifesi FK, Makumba W, Sileshi G, Ajayi OC, Mweta D(2007) Synergistic effect of inorganic N and P fertilizers andorganic inputs from Gliricidia sepium on productivity ofintercropped maize in Southern Malawi. Plant Soil 294:203–217

Akinnifesi FK, Chirwa PW, Ajayi OC, Sileshi G, Matakala P,Kwesiga FR, Harawa H, Makumba W (2008) Contributions ofagroforestry research to livelihood of smallholder farmers inSouthern Africa: 1. Taking stock of the adaptation, adoptionand impact of fertilizer tree options. Agricultural Journal 3:58–75

Akinnifesi FK, Sileshi G, Franzel S, Ajayi OC, Harawa R, MakumbaW, Chakeredza S, Mng’omba SA, de Wolf J, Chianu J (2009)On-farm assessment of legume fallows and other fertilitymanagement options used by smallholder farmers in southernMalawi. Agricultural Journal 4:260–271

Akinnifesi FK, Ajayi OC, Sileshi G, Chirwa PW, Chianu J (2010)Fertilizer tree systems for sustainable food security in the maize-based production systems of East and Southern Africa Region: areview. J Sustain Dev. doi:10.1051/agron/2009058

Arnold JE, Dewees PA (1995) Tree Management in Farmer Strategies:Responses to Agricultural Intensification. Oxford UK: OxfordUniversity Press. 304 p. (Paperback edition, 1997, Farms, Trees,and Farmers: Responses to Agricultural Intensification, London:Earthscan)

Barnes RD, Fagg CW (2003) Faidherbia albida. Monograph andAnnotated Bibliography. Tropical Forestry Papers No 41, OxfordForestry Institute, Oxford, UK. 281 p

Barro A, Zougmoré R, Taonda SJB (2005) Mécanisation de latechnique du zaï manuel en zone semi-aride. Cahiers Agricultures14:549–559

Boffa, J. M. (1999). Agroforestry Parklands in sub-Saharan Africa.FAO Conservation Guide 34, Food & Agriculture Organization,Rome. 254 p.

Botoni, E. Reij, C. (2009). La transformation silencieuse del’environnement et des systèmes de production au Sahel:L’impacts des investissements publics et privés dans la gestiondes ressources naturelles. Amsterdam, the Netherlands: ComitéPermanent Inter-Etats de Lutte Contre la Secheresse dans le Sahel(CILSS) and Vrije University Amsterdam. 175 p.

Broekhuyse, J. T. (1983). Transformatie van Mossi land. Amsterdam,the Netherlands: Koninklijk Instituut voor de Tropen.

Carr S (1997) A green revolution frustrated: Lessons from the Malawiexperience. Afr Crop Sci J 5:93–98

210 D.P. Garrity et al. Author's personal copy

Chirwa PW, Ong CK, Maghembe J, Black CR (2007) Soil waterdynamics in intercropping systems containing Gliricidia sepium,pigeon pea and maize in southern Malawi. Agroforest Syst69:29–43

Denning G, Kabambe P, Sanchez P, Malik A, Flor R, Harawa R,Nkhoma P, Zamba C, Banda C, Magombo C, Keating M,Wangila J, Sachs J (2009) Input subsidies to improve smallholdermaize productivity in Malawi: toward an African green revolu-tion. PLoS Biology 7:2–10

Devereux S (2009) Why does famine persist in Africa? Food Security1:25–35

Devereux S, Maxwell S (eds) (2001) Food Security in Sub-SaharanAfrica. ITDG, London

Dramé YA, Berti F (2008) Les enjeux socio-économiques autour del’agroforesterie villageoise à Aguié (Niger). Tropicultura26:141–149

Famine Early Warning Systems Network (2007) Monthly reports(2005–2007). Available: http://www.fews.net/Pages/country.Accessed 17 December 2008.

Food & Agriculture Organization (2007) The state of food andagriculture. United Nations Food & Agriculture Organization,Rome

Food & Agriculture Organization of the United Nations (2008).FAOSTAT database. Production: Crops. Available: http://faostat.fao.org/site/567/default.aspx. Accessed 18 December 2008.

Funk CC, Brown ME (2009) Declining global per capita agriculturalproduction and warming oceans threaten food security. FoodSecurity 1:271–289

Garrity DP (2004) Agroforestry and the achievement of the millen-nium development goals. Agroforest Syst 61:5–17

Garrity, D. P. (2010). Hope is Evergreen. Our Planet May: 28–30.Garrity D, Verchot L (2008) Meeting Challenges of Climate Change

and Poverty through Agroforestry. World Agroforestry Centre,Nairobi, p 8

GEF (Global Environment Facility) (2003). What Kind of World? Thechallenge of land degradation. Global Environment Facility(GEF), p. 4.

Hadgu, K. M. (2008). Temporal and spatial changes in land usepatterns and biodiversity in relation to farm productivity atmultiple scales in Tigray, Ethiopia. PhD dissertation, WageningenUniversity, Netherlands. 174 p

Haggblade, S., & Tembo, G. (2003). Early Evidence on ConservationFarming in Zambia. EPTD Discussion Paper 108. WashingtonDC: International Food Policy Research Institute.

Jones PG, Thornton PK (2003) The potential impacts of climatechange in tropical agriculture: the case of maize in Africa andLatin America in 2055. Glob Environ Change 13:51–59

Kaboré, D., Reij, C. (2004). The emergence and spread of animproved traditional soil and water conservation practice inBurkina Faso. Environment and Production Technology DivisionWorking Paper No. 114. Washington, DC: International FoodPolicy Research Institute. 338 p.

Kandji ST, Verchot L, Mackensen J (2006) Climate change andvariability in Southern Africa: impacts and adaptation in theagricultural sector. ICRAF/UNEP, Nairobi, p 36

Kaonga M, Bayliss-Smith TP (2008) Carbon pools in tree biomassand the soil in improved fallows in eastern Zambia. AgroforestSyst 76:37–51

Katanga R, Kabwe G, Kuntashula E, Mafongoya PL, Phiri S (2007)Assessing Farmer Innovations in Agroforestry in Eastern Zam-bia. J Agr Educ Ext 13:117–129

Kumar BM, Nair PKR (2006) Tropical Homegardens. Springer,Dordrecht, p 377

Kwesiga F, Coe R (1994) Potential of short-rotation Sesbania fallowsin eastern Zambia. For Ecol Manage 64:161–170

Kwesiga F, Akinnifesi FK, Mafongoya PL, Mcdermott MH, AgumyaA (2003) Agroforestry research and development in southernAfrica during 1990s: Review and challenges ahead. AgroforestSyst 53:173–186

Kwesiga, et al. (2005). Improved Fallow Practices in Eastern Zambia.EPTD Discussion Paper No. 130. Washington, DC: InternationalFood Policy Research Institute. 285 p.

Lal R (2009) Soil degradation as a reason for inadequate humannutrition. Food Security 1:45–58

Lal R (2010) Beyond Copenhagen: mitigating climate change andachieving food security through soil carbon sequestration. FoodSecurity 2:169–177

Lamb RL (2000) Food crops, exports, and the short-run policyresponse of agriculture in Africa. Agr Econ 22:271–298

Larwanou, M., Adam, T. (2008). Impacts de la régénération naturelleassistée au Niger: Etude de quelques cas dans les Régions deMaradi et Zinder. Synthèse de 11 mémoires d’étudiants de 3èmecycle de l’Université Abdou Moumouni de Niamey, Niger.Photocopy. 49 p.

Larwanou, M., Abdoulaye, M., Reij, C. (2006). Etude de larégénération naturelle assistée dans la Région de Zinder (Niger):Une première exploration d’un phénomène spectaculaire. Wash-ington, D.C.: International Resources Group for the U.S. Agencyfor International Development. 385 p.

Mafongoya, P. L., Kuntashula, E., Sileshi, G. (2006). Managing soilfertility and nutrient cycles through fertilizer trees in southernAfrica. In: Uphoff N, Ball AS, Fernes E, Herren H, Husson O,Liang M, Palm C, Pretty J, Sanchez P, Sanginga N, Thies J (eds).Biological Approaches to Sustainable Soil Systems, Taylor &Francis, (pp 273–289).

Makumba W, Janssen B, Oenema O, Akinnifesi FK, Mweta D, KwesigaF (2006) The long-term effects of a Gliricidia-maize intercroppingsystem in southern Malawi, on Gliricidia and maize yields, andsoil properties. Agric Ecosyst Environ 116:85–92

Makumba W, Akinnifesi FK, Janssen B, Oenema O (2007) Long-termimpact of a Gliricidia-maize intercropping system on carbonsequestration in southern Malawi. Agric Ecosyst Environ118:237–243

Matlon PJ (1990) Improving productivity in sorghum and pearl milletin semi-arid Africa. Food Res Inst Stud 22:1–43

Matlon PJ, Spencer DS (1984) Increasing food production in Sub-Saharan Africa: environmental problems and inadequate techni-cal solutions. Am J of Agric Econ 66:672–676

Monimart M (1989) Femmes du Sahel: La désertification auquotidien. Editions Karthala/Organisation for Economic Cooper-ation and Development Club du Sahel, Paris, p 263

Neufeldt, H., Wilkes, A., Zomer, R. J., Xu, J., Nang’ole, E., Munster,C., Place, F. (2009). Trees on farms: Tackling the triplechallenges of mitigation, adaptation and food security. WorldAgroforestry Centre Policy Brief 07. Nairobi, Kenya: WorldAgroforestry Centre.

Phombeya, H. S. K. (1999). Nutrient sourcing and recycling byFaidherbia albida trees in Malawi. PhD Dissertation, WyeCollege, University of London. 219 p

Phombeya H (2009) MAFE Land Resource Centre, Lilongwe.Malawi, Personal Communication

Place, F., Adato, M., Hebinck, P., Omosa, M. (2005). The impact ofagroforestry-based soil fertility replenishment practices on thepoor in Western Kenya. Research Report 142. Washington, D.C.:International Food Policy Research Institute and World Agrofor-estry Centre.

Pye-Smith C (2008) Farming Trees, Banishing Hunger: How anagroforestry programme is helping smallholders in Malawi togrow more food and improve their livelihoods. World Agrofor-estry Centre, Nairobi, p 27

Evergreen Agriculture: sustainable food security in Africa 211 Author's personal copy

Reij, C. (1983). L’évolution de la lutte anti-érosive en Haute Volta:Vers une plus grande participation de la population. Institutefor Environmental Studies, Vrije University, Amsterdam, theNetherlands.

Reij C, Thiombiano T (2003) Développement rural et environnementau Burkina Faso: La réhabilitation de la capacité productive desterroirs sur la partie nord du Plateau Central entre 1980 et 2001.Ambassade des Pays-Bas, German Agency for TechnicalCooperation- PATECORE, and U.S. Agency for InternationalDevelopment, Ouagadougou

Reij, C., Tappan, G., Smale, M. (2009). Agroenvironmental Transfor-mation in the Sahel: Another Kind of “Green Revolution”. IFPRIDiscussion Paper 00914. Washington DC: International FoodPolicy Research Institute.

Republic of Malawi (2008). Malawi poverty and vulnerability assess-ment: Investing in our future. Volume II: June draft for discussion.Lilongwe: Republic of Malawi and World Bank. Available: http://www.aec.msu.edu/fs2/mgt/caadp/malawi_pva_draft_052606_final_draft.pdf. Accessed 17 December 2008.

Rhoades C (1995) Seasonal pattern of nitrogen mineralization and soilmoisture beneath Faidherbia albida (syn Acacia albida) incentral Malawi. Agrofor Sys 29:133–145

Saka AR, Bunderson WT, Itimu OA, Phombeya HSK, Mbekeani Y(1994) The effects of Acacia albida on soils and maize grainyields under smallholder farm conditions in Malawi. For EcolManag 64:217–230

Sanchez, P. A. (1994). Tropical soil fertility research: Towards the secondparadigm. P. 65–88. In Inaugural and state of the art conferences.Transactions 15thWorld Congress of Soil Science. Acapulco,Mexico.

Sanchez P (2002) Soil fertility and hunger in Africa. Science295:2019–2020

Sanchez PA, Swaminathan MS (2005) Cutting world hunger in half.Science 307:357–359

Sanginga N, Woomer PL (2009) Integrated soil fertility managementin Africa: principles, practices, and developmental processes.TSBF-CIAT, Nairobi, p 263

Scherr S, McNeely J (2009) Farming with Nature: The Science andPractice of Ecoagriculture. Island, Chicago, 473 p.

Schmidhuber J, Tubiello FN (2007) Global food security underclimate change. Proc Natl Acad Sci 104:19703–19708

Scoones, I., Toulmin, C. (1999). Policies for soil fertility managementin Africa. A report prepared for the Department for InternationalDevelopment (DFID). IDS, Brighton/IIED, Edinburgh. 128 p.

SEI (Stockholm Environment Institute) (2005). Sustainable pathwaysto attain the millennium development goals—assessing the roleof water, energy and sanitation. Research report prepared for theUN World Summit, 14 September, 2005, New York. StockholmEnvironment Institute, Stockholm http://www.sei.se/mdg.htm

Shepherd KD, Walsh MD (2007) Infrared spectroscopy – enabling anevidence-based diagnostic surveillance approach to agricultural

and environmental management in developing countries. J NearInfrared Spectrosc 15:1–19

Sileshi G, Mafongoya PL (2006) Long-term effect of legume-improved fallows on soil invertebrates and maize yield in easternZambia. Agric Ecosyst Environ 115:69–78

Sileshi G, Kuntashula E, Mafongoya PL (2006) Legume improvedfallows reduce weed problems in maize in eastern Zambia.Zambian Journal Agric Sci 8:6–12

Sileshi G, Akinnifesi FK, Ajayi OC, Place F (2008) Meta-analysis ofmaize yield response to woody and herbaceous legumes in thesub-Saharan Africa. Plant Soil 307:1–19

Sileshi G, Akinnifesi FK, Debusho LK, Beedy T, Ajayi OC,Mng’omba S (2010) Variation in maize yield gaps with plantnutrient inputs, soil type and climate across sub-Saharan Africa.Field Crops Res 116:1–13

Smith, G. (2009). http://www.alertnet.org/db/an_art/60167/2009/10/17-113135-1.htm.

Snapp SS, Mafongoya PL, Waddington S (1998) Organic mattertechnologies for integrated nutrient management in smallholdercropping systems of southern Africa. Agric Ecosyst Environ71:185–200

Swift, M. J., Shepherd, K. D., (eds). (2007). Saving Africa’s Soils:Science and Technology for Improved Soil Management in Africa.Nairobi: World Agroforestry Centre. http://worldagroforestry.org/Library/listdetails.asp?id=49775

Syampungani S, Chirwa PW, Akinnifesi FK, Ajayi OC (2010) Thepotential of using agroforestry as a win-win solution to climatechange mitigation and adaptation and meeting food securitychallenges in Southern Africa. Agr J 5:80–88

Tougiani A, Guero C, Rinaudo T (2009) Community mobilisation forimproved livelihoods through tree crop management in Niger.GeoJournal 74:377–389

Tripp R (2005) The performance of low external input technology inagricultural development: a summary of three case studies. Int JAgric Sustain 3:143–153

UNEP/ISRIC. (1991). World Map of the Status of Human-InducedSoil Degradation (GLASOD). An Explanatory Note (2nded.). UNEP, Nairobi, Kenya, and ISRIC, Wageningen,Netherlands

United Nations. (2004). World Population to 2300. Department ofEconomic and Social Affairs/Population Division, New York:United Nations Secretariat. 254 p.

WRI (World Resources Institute) (2008). Turning back the desert:How farmers have transformed Niger’s landscapes and live-lihoods. In Roots of resilience: Growing the wealth of the poor.Washington, D.C.: World Resources Institute.

Zomer, R. J., Trabucco, A., Coe, R., Place, F. (2009). Trees on Farm:Analysis of Global Extent and Geographical Patterns ofAgroforestry. Nairobi: World Agroforestry Centre, ICRAFWorking Paper No 89.

212 D.P. Garrity et al. Author's personal copy

Dennis Philip Garrity is asystems agronomist whose careerhas been focused on the develop-ment of small-scale farming sys-tems in the tropics. He is DirectorGeneral of the World Agroforest-ry Centre, which advances thescience underpinning a massiveincrease in the use of trees inagricultural landscapes by small-holder rural households for im-proved food security, nutrition,income, health, shelter, energyand environmental sustainability.He also currently chairs the

Global Steering Committee of Landcare International, a community-based approach that drives innovative solutions to natural resourcemanagement challenges. Previously, Dr Garrity served as regionalcoordinator of the Centre’s work in Southeast Asia, and earlier headedthe Agroecology Unit at the International Rice Research Institute in thePhilippines.

Festus K. Akinnifesi obtained aBSc in Forestry in 1988 and aPhD in Agronomy in 1995 fromthe University of Ibadan. SinceJanuary 2000, he has beenworking with the World Agro-forestry Centre (ICRAF). Cur-rently, he is Principal TreeScientist and the Regional Co-ordinator for Southern AfricaRegional Programme. Beforejoining ICRAF he had workedas Visiting Professor at the StateUniversity of Maranhão, SãoLuis, Brazil (1997-1999); Agro-

forestry/Soil Scientist with the Geomatics International Inc., Ibadan(1996-mid 1997); and at various positions with the InternationalInstitute of Tropical Agriculture (IITA) Ibadan, viz, Visiting ResearchFellow (1992-1994), Research Associate (Jun-Dec, 1992), andResearch Assistant (1988-1990). He is an Extra-Ordinary Professorat Stellenbosch University, South Africa. He is an Editor of SouthernForest Journal and an Associate Editor of Agroforestry Systems. Histwo decades of research have focused on the development of optionsfor robust soil fertility replenishment that are natural, low-cost andsustainable through the use of fertilizer trees and also on thedomestication of indigenous fruit trees of the tropics.

Oluyede Clifford Ajayi is aSenior Agricultural Economistwith the World AgroforestryCentre (ICRAF). He obtained hisPhD in Agricultural Economicsfrom the University of Hannover,Germany in 1999. His currentresearch work focuses on eco-nomic evaluation, adoption andscaling-up of natural resourcemanagement practices to improvefood security and alleviate pover-ty, especially among smallholderhouseholds. He has previouslyworked on cotton and rice-based

farming systems at the International Institute of Tropical Agriculture(IITA) and The African Rice Centre (WARDA), respectively, and wasengaged in improving livelihoods and sustainable agriculture forsmallholder farmers in these farming systems. He is a reviewer forseveral international journals. He is currently based in ICRAF’s SouthernAfrican regional office located in Malawi.

Sileshi G. Weldesemayat is anagroecologist with the World Ag-roforestry Centre. He obtainedhis PhD degree in Zoology fromKenyatta University in 2001. Hismajor research interest is in inte-grated pest management and pro-duction ecology. He is currentlybased at ICRAF’s SouthernAfrica Programme in Malawi,and undertakes research anddevelopment on plant and soilhealth.

Jeremias Gasper Mowo is aSenior Scientist with the WorldAgroforestry Centre (ICRAF).He is the ICRAF Eastern AfricaRegional Representative andRegional Coordinator for theAfrican Highlands Initiative(AHI) with 30 years of profes-sional experience in agriculturalresearch for development. Heobtained his PhD in Soil Sciencefrom Wageningen University, theNetherlands in 2000 and his majorarea of interest is integrated natu-ral resource management (INRM).

Evergreen Agriculture: sustainable food security in Africa 213 Author's personal copy

Antoine Kalinganire obtainedan M.Phil. in Forestry from theUniversity of Wales, UK in 1992and his Ph.D. in Forestry Geneticsfrom the Australian NationalUniversity, Canberra in 1999.His areas of expertise includeresearch resource mobilization,project design, management andthe development of strategic part-nerships. Forest genetics are animportant interest with its link-ages to conservation, domestica-tion, food security and povertyreduction for poor smallholder

farmers. Dr Kalinganire is also involved with on-farms trials, includingEvergreen Agriculture with trees for enhanced productivity.

Mahamane Larwanou obtainedhis Bachelors and MastersDegrees in Forest Ecology/Ag-roforestry in 1992 and 1994,respectively, from the Universi-ty of Ibadan, Nigeria. Aftergraduation he was recruited bythe Institut National de la Re-cherche Agronomique du Niger(INRAN) as a research scientistin the Forestry Department. Inthis position, he obtained hisDoctorate Degree in 2005 atthe Department of Plant Biolo-gy of the Faculty of Sciences,

University Abdou Moumouni of Niamey. He left INRAN in 2006 tojoin the University of Niamey as a lecturer and research scientist

and in 2008 joined the African Forest Forum (AFF), hosted by theWorld Agroforestry Centre (ICRAF), in Nairobi, Kenya as theSenior Programme Officer. While in Niger he conducted research inforestry and agroforestry, developing various agroforestry technol-ogies aimed at improving parkland systems in the Sahel. He haspublished many articles in peer reviewed scientific journals andcoordinated many scientific collaborative projects.

Jules Bayala obtained his PhDfrom the University of Wales, Ban-gor, UK in 2002. He has 20 yearsof experience in forestry andagroforestry and his research fo-cuses on tree-crop interactions inagroforestry systems, eco-physiology of woody speciesand mathematical modeling oftree-crop interactions. He hascoordinated many bilateral andmultilateral projects. Since 2007,he has been a consultant for theInternational Atomic EnergyAgency. From 2006 to 2009 he

was a member of the steering committee of CIFOR’s Regional Office forWest Africa project “Dry forest Projects”. In January 2009, he becamethe head of the forestry department of INERA before joining ICRAF inNovember 2009.

214 D.P. Garrity et al. Author's personal copy