Book-coverEver hear of farming systems research, training and visit, participatory rural appraisal? If so, chances are you’re a veteran of the 1970s and 80s era war on food insecurity then blitzing across the African continent. This war had no generals, shock troops, enfilades, pincer movements, or Maginot line to defend. No hearts and minds to spar over. As Henk J.W. Mutsaers tells it, the battle was played out in the rarefied confines of elite international research centers, extension bunkers, and donor silos, edging off into the tactical embrace of consultants and purveyors of development aid armed with infectious goodwill and an appetite for money. Its Waterloo moment came in the late 1990s when the patience of the World Bank, IMF, and bilateral and philanthropic entities had been tried enough to cut the cord and move on. Now, as ever, Africa’s production of cereal grains places at the bottom of global rankings and food deficits in many countries are still endemic. What went wrong?

If the name H.J.W. Mutsaers doesn’t ring a bell, he’s a Dutch agronomist, crop modeling enthusiast, and author of Peasants, Farmers, and Scientists: A Chronicle of Tropical Agricultural Science in the Twentieth Century (Springer, 2007). Part history, autobiography and technical monograph, Peasants, Farmers, and Scientists tells the story of tropical agricultural science and agricultural development from the beginning of the 20th century, an era of colonial rubber, oil palm, and sugar plantations that beckoned cavalier European agronomists like Henk Mustaers. The book’s eleven chapters, nine appendices, and expansive bibliography dish up, on a non-trivial yet comprehensible level, the evolution of tropical agriculture science from colonial handmaiden to development agent focusing primarily on the interplay of donors, scientists (local and foreign), research centers, and farmers in West and Central Africa in the second, post-colonial half of the century. On exhibit are field notes, disputations, and scientific gleanings from the author’s far-flung gigs as researcher in the Dutch East Indies (now Indonesia); lecturer at Wageningen Agricultural University in the Netherlands and at the Ecole Nationale Supérieure Agronomique (ENSA), near Yaoundé, Cameroon; researcher at the International Institute of Tropical Agriculture in Ibadan, Nigeria, West Africa; and lately, freelance consultant.1

Figure 1. Native stone terraces in the Mandara Mountains, northern Cameroon. The terraces capture rainfall during the brief rainy season, improving water infiltration and conserving soil. Sorghum and millet are the principal crops in this semi-arid zone.

For the uninitiated, you’ll learn the nitty-gritty of shifting cultivation (“the mother of all systems”), sugarcane breeding, clever indigenous farming practices, experimental smallholder technologies, crop modeling (of course), innovative methods for evaluating technology in farmer’s fields, and agro nutrient budgets. Astonishing practices like “écobuage”, described anecdotally in Chapter 5 “Forests, Fallows and Fields” as a method of slowly burning grass residue in soil trenches under low oxygen conditions in western Cameroon anticipate the concept of pyrolysis for biochar production. In Nigeria, there’s an ingenious Yoruba maize-sorghum-yam rotation that modern agroecologists would have a hard time improving on; native soil- and moisture-conserving stone terraces in the Mandara Mountains of northern Cameroon (Figure 1); and, the obscure “van der Meulen” method of speargrass (Imperata cylindrica) suppression and soil rejuvenation that exploited the peculiar habits of two legumes, velvet bean (Mucuna pruriens) and Centrosema, and a deep-rooted invasive Eupatorium species (Chromolaena odorata), to further whet your appetite.  Since my blogging time is limited to after hours and weekend punting, and the attention span of online readers abridged, I’ll limit my comments to a couple of resonant themes in Peasants, Farmers, and Scientists about African agriculture, to which I can add substance.

The first theme turns about this question: Can a modern market-centered African agriculture evolve from its peasant roots, or will this require a completely different mindset? At one time Mutsaers believed that Africa’s peasant-farmers could make the transition to a market platform if alternatives to slash and burn could be found. This view is embedded in the idea that the traditional subsistence farmer is a rational operator, or at least what we consider rational in a post-subsistence, modern agribusiness world. The idea is that improved genetics, fertilizer, lime, nitrogen-fixing legumes, and other inputs should improve return to labor and land, fostering sustainability while accelerating the transition to a market-centered enterprise.

Ah, but the picture has always been (and still is) much more complicated than that. Technologies like no-tillage planting failed to take root in sub-Saharan Africa only to blossom in Southern Africa, North and South America. Promising non-mechanized “appropriate” technologies aimed squarely at resource-limited smallholders have also fallen flat. Take alley cropping, for example. Briefly, alley cropping is a method of planting annual agricultural crops between rows of perennial trees, especially fast-growing multipurpose nitrogen-fixing species such as white lead tree (Leucaena leucocephala), Erythrina (Erythrina poeppigiana), and Gliricidia (Gliricidia sepium) (Figures 2a and 2b).

Figure 2. (a) Alley cropping in the highlands of western Cameroon. Note the large unpruned perennial trees. Perennials furnish green manure but they can also compete aggressively with food crops for moisture and nutrients. (b) Raised beds planted with maize, bean, and cocoyam. Intercropping is favored by peasant-farmers in Africa, but agronomists prefer monocropping because management is easier with a single crop.

A typical alley cropping scenario involves intercropping maize with root crops (sweet potato, cassava, cocoyam) or cowpea, or a combination in succession, between trees planted about 4 meters apart. The trees are pruned to small hedges at the start of the growing season, and perhaps once or twice thereafter, with trimmings placed in the alleys as “green” manure. The concept of green manuring reaches back to antiquity: Roman agricultural writer Varro (116 – 27 BC) advised plowing under legumes like beans and lupine in their green, unripened state for soil improvement. Cato, Columella, and Pliny gave similar advice. Alley cropping updates the green manure concept to include woody perennial species.

Popularized by B.T. Kang, G.F. Wilson and colleagues at the International Institute of Tropical Agriculture (IITA) in Ibadan, Nigeria, alley cropping aimed to mimic elements of traditional slash and burn agriculture where trees are cut down, but the roots are left intact. After a period of cropping, the tree stumps resume their growth. Competition from sprouting trees and weeds, coupled with soil nutrient depletion, stimulated the traditional slash and burn farmer to seek new ground every 2-3 years. Thus arose the term “shifting” cultivation. Alley cropping short-circuited this endlessly itinerant slash and burn cycle by planting, purposefully, deep-rooted perennial trees to capture nutrients that leach down beneath shallow-rooted annual food crops. The dodgy nutrients are returned to the surface in the tree’s vegetative parts fortified with minerals from the subsoil. Tree trimmings are mixed in the soil where they decompose, releasing the plant-essential nutrients and leaving behind a residue of humus. To facilitate farm operations, trees were planted in straight lines, leaving the interspace open for mechanized cultivation, if feasible. Superficially, alley cropping seems like the perfect, sustainable, and eco-friendly alternative to slash and burn.

Turns out, alley cropping is not always the perfect recipe it seems to be. Mutsaers parses the quantitative details in appendix 4 “Nutrient Dynamics of Alley Cropping: A Simple Model”, for agronomists are also ruthless nit-picking scientists who are never satisfied until the numbers add up in the biophysical balance of accounts. If you steal from Peter to pay Paul, eventually you bump up against a form of biological entropy, or ever-diminishing returns. Crop and soil modeling is an excellent way to test this principle by way of predicting how the system will react to the ebb and flow of energy and nutrients. To my knowledge, this is the first attempt to simulate long-term soil and crop productivity under alley cropping in the humid tropical forest zone. Indeed, the author even voices surprise that it had never been done after so many years of alley cropping research.

If Mutsaers’s soil and plant nutrient allowances are taken as reasonable approximations, and the assumptions about system productivity are met, his simple model predicts that even on a favorable site with “good” soil, continuous maize-cassava and maize-cowpea alley cropping would be impossible in the long run without supplemental fertilizer. The demand for mineral nutrients needed to sustain continuous cropping is predicted to outstrip available stocks even in the subsoil. As the soil’s nutrient stocks are siphoned off in food products, the production of tree trimmings eventually declines to a point where the system collapses under the strain of nutrient exhaustion. Mutsaers concludes, rightly, that alley cropping is a form of soil mining, especially the macro-nutrients phosphorus and potassium (calcium, magnesium, sulfur, and micronutrients were not considered in the models). In fact, Mutsears’s model predictions were borne out, in principle, by measured crop yields from two, 12-year alley cropping experiments in Nigeria, one with non-fertilized maize and cassava, reported by Tian et al. (2003; 2005) and, a maize-cowpea system with fertilizer phosphorus and potassium, reported by Kang et al. (1999). Mutsaers admits taking some liberties in making assumptions about soil and plant processes in his alley cropping simulations, which may not extend to other soils and agroecological zones. One could quibble over his choice of 10 parts per million as a critical available soil phosphorus (P) level for maize production, which seems on the low side, but this depends on the type of extractant used to measure soil P and other factors like soil texture, nitrogen uptake, and capacity for P-immobilization.

Not coincidentally, a similar picture emerged from research by L.T. Szott, C.A. Palm, and P.A. Sanchez (1991)  following a series of alley cropping trials in the Peruvian Amazon with upland rice and cowpea (Figures 3a and 3b).

Figure 3. (a) Alley cropping experiments in the Peruvian Amazon with upland rice flanked by perennial ice-cream bean (Inga edulis). Note the straight lines and uniform spacing of rice plants in the middle and uniform distribution of Inga trimmings in (b). Controlled experiments like these were (and still are) the rule on agricultural research stations in the tropics, yet they failed to replicate the haphazard conditions of farmer’s fields.

While it’s impossible to relate all of the details here, Szott and coworkers concluded that even with legumes pruned as hedges or as the principal crop, or both, continuous alley cropping was not sustainable on acid, infertile Amazonian soils without nutrient subsidies from outside the system. In other words, alley cropping failed to measure up in two, distinct agroecological zones in Africa and South America. In the end, however, the promise of alley cropping did not fail because of nutrient exhaustion, which was predicted by Mutsaers’ crop-soil models and borne out by multiple field trials in West Africa and Peru. The problem was that farmers did not want to adopt alley cropping, a separate conundrum I’ll try to unpack.

The concept of technology transfer is deeply embedded in just about every interpretation of agricultural development. Nowadays it’s more avant-garde to speak of “value chains” but this is just a purloined buzzword that alienates donor-side bureaucrats from the untidy prospect of intervening in agricultural production systems. In the putative research-extension alliance, technology, loosely defined, is generated by scientists and the products are then disseminated by specialists schooled in the repertoire of the donor “recipients”, in this case, peasant farmers. In principle, the spread of improved technology to rural producers is accelerated by public agencies, acting alone, or in concert with international organizations. It’s a simplistic approach with many pitfalls. Perhaps its biggest flaw was the assumption that the priorities of public agencies, international organizations, and rural producers were mutually sympathetic. In fact, this was rarely the case. Thus, agronomists could push novelties like alley cropping even though labor demand, access to inputs, land tenure, and other fixtures of the peasant-farmers life were such that there was no reason for farmers to change what they were already doing, except perhaps in exchange for free donor-supplied goodies while they lasted. Mutsaers concedes that this was a major obstacle to disseminating improved practices coming out of the research stations. There were other lurking pitfalls too, rising from unexpected quarters. Let me illustrate the “lurking pitfalls” point with a couple of examples from my trench-level experience in Sierra Leone with cassava and rice.

Cassava (Manihot esculenta) is a traditional root crop in Africa, though scarcely known outside of its native tropical habitat. As Mutsaers points out, cassava is alien to Africa; the plant was, in fact, introduced there from Brazil by Portuguese traders in the 16th century. Cassava is a tough plant that tolerates uncertain rainfall and marginal soil, two compliant virtues that have earned it the nickname “bread of the tropics”. One of cassava’s weak spots is its susceptibility to the African cassava mosaic virus, first reported from East Africa in 1894. Virus epidemics have severely impacted cassava production resulting in great economic losses and in some cases, famine. In the 1970s high priority was given to breeding mosaic resistant cassava. Scientists at the IITA in Nigeria managed to do this by drawing on parent varieties developed by earlier crossing M. esculenta with virus-resistant tree cassava (Manihot glaziovii,  believed to be a natural hybrid of Ceara rubber and cassava) species at the Amani research station in East Africa (the actual breeding process is much more complex than a simple crossing of two species but I leave the details out…). Back then, I was given some virus-resistant cassava “sticks”, as the vegetative stem cuttings are known, and advised to propagate them and give the offspring to farmers (Figure 4).

Figure 4. Mosaic resistant cassava growing in the author’s multiplication nursery. Local reaction to it was lukewarm.

In theory, this was a good idea. In practice, it proved less redeeming. While the virus-free cassava increased beautifully, it wasn’t a hit with the locals. Breeding resistance to the cassava mosaic virus, it seems, also thickened the cassava leaf epidermis. Perhaps this was by design because the leaf-feeding whitefly is the principal vector of cassava mosaic (other anatomical and/or phytochemical traits may also have been affected; the exact resistance mechanism is unknown to me). In the event, the culinary properties of the virus-resistant cassava leaf were noticeably different. Farmers complained that it wasn’t “sweet” like the native varieties. I should point out that eating cassava leaves was almost a daily ritual in Sierra Leone, so local preference may have steered people’s reactions. Over time in Sierra Leone I, too, had acquired a taste for the native leaf, and the virus-free cassava was not the same!

Figure 5. (a) Slash and burn farm in Sierra Leone. The tall grass surrounding the farmhouse is upland rice.  (b) Typical inland valley rice farm near Kenema, Sierra Leone. Hazards like schistosomiasis and river blindness were a constant risk to farmers working in these fields.

Similar resistance was encountered trying to disseminate improved japonica rice varieties bred at the International Rice Research Institute (IRRI) in the Philippines, which were increased locally by the West African Rice Development Association (WARDA). The IRRI varieties grew beautifully with fertilizer and controlled irrigation but they lacked the fluffy texture and sweet flavor of native Mende upland “red” rice (Oryza glabberima) produced under traditional slash and burn cultivation (Figure 5).  Swamp rice was a tough sell to slash and burn farmers, as were environment controls like irrigation, seedling nurseries, and line-planting with sticks and string. Of course, fertilizer was out of the question for most farmers, so it was natural for them to favor the native rice varieties that were better adapted to Sierra Leone’s acid, infertile upland soils, in spite of the generally low grain yield. But why did agronomists ignore upland rice? Breeding programs for upland rice did not exist in Sierra Leone, nor did initiatives aimed at finding ways to stabilize upland production systems2. The answer lay in the swamps, and the battle cry was “develop them!”.

What does this say about the African peasant farmer’s capacity for change? Henk Mutsaers confesses that he’s had second thoughts about the idea of re-wiring the traditional peasant-farmer for the future. Commercial, market-centered farming in Africa may take a completely different mindset that can only be gestated de novo rather than inoculated through participatory rural appraisal and training and visit confabs. Indeed, there are signs of a new entrepreneurial vanguard in the ascendant peri-urban farming movement, taking its lead from a sophisticated reading of urban markets and demographics (a global phenomenon, actually). Curiously, Mutsaers is silent about the ever-spreading Chinese footprint in Africa, in progress now for well over a decade and bound to deeply impact African agriculture and markets. Of course the Chinese are certainly not the only players in the global land grab; perusal of the Oakland Institute’s Understanding Land Investment Deals in Africa indicates a diverse mix of public and private stakeholders.  In the event, the verdict is still out on the transglobal farming model. If carefully implemented and managed, it is plausible that vertically integrated, “international” farming may contribute to the long-awaited green revolution in Africa. On the other hand, I don’t see why farmers must conform to any particular mold. Why can’t African farmers be traditional and market-centered, or a mixture of both? After all, there are greater extremes coexisting in the industrialized West: artisan modes of production e.g. organic and specialty farm-to-table operations in the shadow of industrial mega-farms in the Midwestern USA. I think there’s room for everyone’s persuasion.

Returning to the subject of technology transfer, the failure of farming systems research (FSR) and other donor-inspired fads in Africa gives one pause to contemplate the legacy of foreign intervention in agricultural production systems. Africa is rife with monuments bearing witness to well-intentioned but ultimately botched attempts to reshape African agriculture along modern lines (Figure 6).

Figure 6. All your tractor are belong to us. Soviet-era Russian tractor stands sentinel near Ngaoundéré, Cameroon, evoking some long-ago combat scene.

The Farm Settlement schemes in Anglophone countries mostly failed their objectives; the 1980s Unités Expérimentales research-extension alliance in Sénégal was hit and miss; the Tanganyika Groundnut Scheme, an epic failure; the Gezira-irrigated cotton scheme in Sudan, a marvel of engineering that failed to cash flow its infrastructure (now transitioning to rice?); and the infamous Office du Niger-irrigated rice scheme in Mali. The Office du Niger project is arguably the most enduring of the lot, but its fate since the 2012 insurgency remains unknown. In Africa, everything seems to hang by a gossamer. As Henk Mutsaers opines, for all the foreign aid directed at alleviating food insecurity in Africa over the past half-century, measurable impacts can scarcely be detected. Why?

Unfortunately, Mutsaers offers no cogent, unambiguous answer. Insofar as the FSR-inspired bandwagon was concerned, the author observed that “research stations in Africa were so different from a real farm that it made no sense at all to do detailed studies on crop management under conditions which only remotely resembled those of the farmer”. Moreover, too many field trials were designed “to rediscover things which had been found out countless times before or were in no great need of being found out”, and answering “evermore detailed questions which originated mainly in the scientists’ own minds, assisted by imaginary conversations with some phantom African farmers”. The author laments the devolution of FSR into a ritualized, self-serving professional cult where incantation of mumbo-jumbo like “linkages” and “capacity building” was valued above tangible outcomes that have a rational basis for measuring. In effect, the return to small scale farming from decades of research and development has been near zero. But not quite. Mutsaers points to some bright spots, like the testing and dissemination of Mucuna pruriens for speargrass control in Bénin Republic by government extension services and the NGO Sasakawa Global 2000 Foundation. Impact studies from the late 1990s estimated that 14,000 farmers had used, or were using, Mucuna.

Is Mucuna still used by farmers in Bénin Republic today? What happened when extension workers stopped providing Mucuna seeds? What lasting influence has Mucuna had on smallholder productivity in Bénin Republic? We do not find these things out because the success of development project “cycles” is measured by short-term impacts, which is quite apart from changing the way people do things, in perpetuity. Generations of agronomists and development workers have relentlessly pitched legumes as cover crops and soil improvers. To paraphrase Henk Mutsaers, one cannot fail to be impressed by the magic of legumes. Legumes, however, are nothing new in agriculture. None the less, each generation seems to rediscover legumes as something equivalent to finding the philosopher’s stone. Each time we’re told it’s a new approach, a new “understanding”. In reality, efforts to convince farmer-peasants in Africa to adopt legumes have been met with very little success. Legumes are fascinating plants valued for their ability to fix atmospheric nitrogen. But it’s unlikely that legumes, alone, or in combination, will herald a green revolution in African agriculture presently or anytime in the future.

Fast-forward: it’s 2014 and we’re still at it, conjuring the right technology ingredients. Lo and behold, a new paradigm is borne unto us: the Millennium Villages, a gem of the Earth Institute at Columbia University, United Nations Development Programme, and Millennium Promise (né 2006). This project delivers fertilizer and hybrid seed, among other offerings. The Soils, Food, and Healthy Communities project in Malawi aims to improve soil fertility, sustainability, and rural livelihoods with legumes (again!) and native open-pollinated crops. A multicolor Compact Technical Report for post-conflict Sierra Leone published by the Comprehensive Africa Agriculture Development Programme (CAADP) is larded with talk of “value chains” and “capacity building” across crops, livestock, and fisheries. And this announcement from AGRA, an anti-poverty project founded in 2006 with support from the Rockefeller Foundation and Bill and Melinda Gates Foundation: “Millions of smallholder farmers need to adopt promising ISFM (Integrated Soil Fertility Management; see Mutsaers, p. 373) options in order to generate sustainable yield increases and make farming more profitable.”

Will smallholders adopt ISFM practices this time around? Will these earnest projects succeed in creating a productive sustainable template for African agriculture, eradicating poverty and food insecurity as their like promised but failed to deliver before? That, of course, is difficult to predict. But the odds aren’t favorable. Such projects may have a local impact, but I predict their long-term influence will scarcely register on the development scale. None the less, African agriculture is destined for tremendous change, but that change will be enabled by forces ungoverned by NGOs and operating outside of their sphere. Tax and public policy incentives, education, patterns of global investment and trade, land tenure reform, mobile digital communication, GIS and deep learning technology, are most likely to stimulate private investment, mechanization, and growth in all sectors including agriculture. For all the infectious goodwill, trampled warriors, and empty aid coffers, this may just be how poverty ends, worldwide.

In closing, I submit that few people have witnessed, let alone examined, honestly, the vacillating tack of agricultural development in the last half of the 20th century as intimately as Henk Mutsaers (the late Norman Borlaug comes to mind). For this reason alone Peasants, Farmers and Scientists stands as a landmark achievement. If you have ever hankered for the philanthropic life, or even donated money for mosquito nets (rumor has it they make superb fishing nets), I urge you to read this book. If you’re not an agronomist, find one to explain the basics. You’re bound to learn something about food production in the process, which is a good thing. For students of international development, it’s mandatory (permission to skip the modeling stuff if it’s not your cup of tea). Sadly, the price of admission is a wallet-busting US $150+ per copy (Springer is an academic publisher catering mainly to institutional clients, no remainders). Even your faithful blogger and Acme Scientific Research Collaborative®CEO was reduced to borrowing a copy, fathom that.

Cheer up though. At least you get to read this blog for free.

End Notes

1Coincidentally, the author and I worked at ENSA in Cameroon but at different times. I was there in the late 1980s during construction of the new campus at Dschang, quite a distance from Yaoundé. The Dschang campus was a World Bank-funded project trumpeted as a new model for agricultural education and development across Africa. As such, the project attracted quite a few scientific luminaries from Europe, Asia, and the U.S. I was not one of them. Nonetheless, it was a prized opportunity to hobnob with (and learn from) some big shots in the field of tropical agriculture.

2The interspecific upland hybrid sativa X glabberima a.k.a. NERICA rice, was finally introduced in 1996 by the Africa Rice Center (né WARDA). NERICA’s creator Monty Jones won the 2004 World Food Prize for his efforts.

Disclaimer: I have no relations with the book author or publisher Springer. Links to digital content in this blog are for the reader’s information only, not an endorsement of that content. 

Updated by the author 18 April 2019. &Link check. Some links remain unresolved.

Second update by the author 27 November 2019. 

Third update by the author 25 January 2022. 

Further Reading

Bingen, R. James and Jacques Faye. 1987. Agricultural Research and Extension in Francophone West Africa: The Senegal Experience. MSU International Development Papers. Reprint No. 13. (verified 19 April 2014)

Kang, B. T., G. O. Kolawole, G. Tian, and F. E. Caveness. 1999. Longterm alley cropping with four hedgerow species on an Alfisol in southwestern Nigeria-effect on crop performance, soil chemical properties and nematode population. Nutrient Cycling in Agroecosystems 54(2): 145–155.

Kleene, P., and H.J.W. Mutsaers. 2012. What is the matter with African agriculture?: Veterans’ visions between past and future. KIT Publishers, Amsterdam. In the same vein as PFS, conversations with those who were (and still are) on the front lines about accomplishments, failures, and what’s needed to meet Africa’s future challenges. Balanced African, Anglo- and Francophone perspectives.

Salazar, A., L.T. Szott, and C.A. Palm. 1993. Crop-tree interactions in alley cropping systems on alluvial soils of the Upper Amazon Basin. Agroforestry Systems 22(1): 67–82.

Szott, L.T., C.A. Palm, and P.A. Sanchez. 1991. Agroforestry In Acid Soils Of The Humid Tropics. p. 275–301. In Nyle C. Brady (ed.), Advances in Agronomy. Academic Press.

Tian, G., B.T. Kang, and G.O. Kolawole. 2003. Effect of fallow on pruning biomass and nutrient accumulation in alley cropping on Alfisols of tropical Africa. Journal of Plant Nutrition 26(3): 475–486.

Tian, G., B.T. Kang, G.O. Kolawole, P. Idinoba, and F.K. Salako. 2005. Long-term effects of fallow systems and lengths on crop production and soil fertility maintenance in West Africa. Nutrient Cycling in  Agroecosystems 71(2): 139–150.

Wallach, B. 1988. Irrigation In Sudan Since Independence. Geographical Review 78(4): 417. (verified 19 April 2014)