Agricultural Productivity In Sub-Saharan Africa Research Articles

Food availability and agricultural productivity in Sub-Saharan Africa

This paper proposes a diagnosis based on estimates in kilocalories of almost all plant food produced, traded and consumed in the continental Sub-Saharan Africa and Madagascar (39 countries), from 1961 to 2003. These estimates are coupled with others (inhabitants, active populations, surfaces) to first show what driving forces lead a country to raise (or not) its production of plant food calories per capita over time. These drivers, not independent from each other, are those of the equation: Production/Inhabitant = (Producers/Inhabitant) × (Hectares/Producer) × (Production/Hectare), with (Production/Hectare) × (Hectares/Producer) = Production/Producer. These tautological relationships make it possible to assess how partial agricultural productivities of land and labour evolve, and more generally to characterize some major pathways of evolution thanks to appropriate statistical and graphical techniques. These pathways appear to be varied and contrasted. The change in output per capita can then be confronted with food availabilities obtained after net imports have been added to food production, and non-food uses have been deducted (seeds, waste, etc.). This approach shows, in particular, a slight improvement in the average per capita availability across the continent. But this availability is still very low and is associated with a worsening trade balance with the rest of the world: positive at the beginning of the period, it has become increasingly negative.

The Impacts of Technology Adoption on Smallholder Agricultural Productivity in Sub-Saharan Africa: A Review

This paper is a review article on the impacts of technology adoption on agricultural productivity in smallholder agriculture in the sub-Saharan African region. The use of agricultural technologies determines how the increase in agricultural output impacts on poverty levels and environmental degradation. Experience and evidence from countries within and around the sub-Saharan African region indicate that returns to agricultural technology development could be very high and far reaching. The factors affecting technology adoption are assets, income, institutions, vulnerability, awareness, labour, and innovativeness by smallholder farmers. Technologies that require few assets, have a lower risk premium, and are less expensive have a higher chance of being adopted by smallholder farmers. There are certain traditional smallholder agricultural technologies in sub-Saharan Africa that also have their own merits. Some of these technologies are more efficient in their use of scarce production resources than modern technologies. Modern researchers should therefore seek to understand the rationale behind traditional smallholder farmer behaviour in technology use. This will make their future technological interventions in smallholder agriculture more effective.

Impact of mulching technology adoption on output and net return to yam farmers in Osun State, Nigeria

ABSTRACT Soil erosion and nutrient depletion present a threat to the food security and sustainability of agricultural production in sub-Saharan Africa (SSA). However, limited rigorous empirical work on the economics of soil conservation exists. This study examines the factors affecting the adoption of mulching technology and its attendant impact on yam output supply and net returns among sampled yam farmers in Osun State, Nigeria. Probit model and propensity score matching were used to analyse the factors influencing the adoption of mulching technology and its impact on yam output and net returns among yam farmers respectively. The study shows that seed quantity and access to credit are the most significant factors influencing the adoption of mulching technology. Yam farmers in the study area who adopted mulching technology were found to experience a higher output supply than non-adopters, which resulted in a positive and significant effect on their output and net return. Hence, policies targeted at increasing yam output through increasing soil fertility need to include mulching technology as a potentially viable option.

Trypanotolerance in N’Dama x Boran crosses under natural trypanosome challenge: effect of test-year environment, gender, and breed composition

BackgroundTrypanosomosis, a protozoal disease affecting livestock, transmitted by Glossina (tsetse) flies is a major constraint to agricultural production in Sub-Saharan Africa. It is accepted that utilization of the native trypanotolerance exhibited in some of the African cattle breeds to improve trypanotolerance of more productive but susceptible breeds, will offer a cost effective and sustainable solution to the problem. The success of this approach is based on the premise that quantitative trait loci previously identified under relatively controlled situations confer useful trypanotolerance under natural field situations. As part of a study to authenticate this hypothesis, a population of 192 cattle, consisting of six batches of N’Dama and Kenya-Boran backcross animals [(N’Dama x Kenya-Boran) x Kenya-Boran] born over the period 2002 to 2006 was constructed. Some of the batches also included pure Kenya-Boran cattle, or N’Dama x Kenya- Boran F1 animals. Each batch was exposed as yearlings to natural field trypanosomosis challenge over a period of about one year; the entire challenge period extending from December 2003 to June 2007. Performance of the animals was evaluated by weekly or biweekly measurements of body weight, packed blood cell volume (PCV), parasitemia score, and number of trypanocide treatments. From these basic data, 49 phenotypes were constructed reflecting dynamics of body weight, packed cell volume (PCV) and parasitemia under challenge.ResultsFemales were distinctly more trypanotolerant than males. F1, backcross and pure Kenya- Boran animals ranked in that order with respect to trypanotolerance. Overall batch effects were highly significant (p<0.001) for most traits, and were generally more significant than the gender or genetic type effects. The superior trypanotolerance of the F1 animals was expressed in all three components of animal defense strategies against pathogens: Avoidance resistance, and tolerance.ConclusionsThe results show that trypanotolerance derived from the N’Dama is expressed under field conditions; and that the trait is primarily additive in nature, being expressed in heterozygous condition and in a three-quarters Boran genetic background. The results further, underscore the complexity of the trait in the field manifesting all three host disease-control strategies, and show the importance of gender and local environmental conditions in determining response to challenge.

A parasitological survey for bovine trypanosomosis in the livestockwildlife ecozone of Northern Tanzania

Aim: Tsetse-transmitted animal and human trypanosomosis is considered to be one of the major constraints to improved livestock and agricultural production in sub-Saharan Africa. A cross sectional survey to determine the prevalence of trypanosomosis and identifying trypanosome species infecting cattle was conducted in Makuyuni division, Arusha region of northern Tanzania, an area where livestock and wildlife graze together. Materials and methods: A total of 239 indigenous Tanzania short horn zebu cattle at four different villages, and of different ages and sex, were randomly selected and sampled. Field examination of Giemsa stained thick and thin blood smears was undertaken. Results: The overall prevalence of slides positive for bovine trypanosomosis was 5% (95% [confidence interval], CI = 2.68.6). The prevalence was significantly higher in Mswaki juu village (7%) and lower in Ortukai (3%). Of the positive cattle, 8/12 (66.6%) had infections with T. vivax and 4/12 (33.3%) T. congolense. No cases of T. brucei were detected. Animals with poor (13.7%) body score were significantly associated with high prevalence of trypanosomes infection than animals with good (2.7%) score. Prevalence of trypanosomes infections was significantly higher in males (8.42%) than in females (2.47%) and increased markedly in cattle aged >4.5 years, with no significant difference among the age group. Conclusion: Because of the risk of trypanosomosis in the Mswaki juu, a locality which is close to a wildlife Reserve; integrated tsetse and trypanosomosis control strategies need to be improved and enforced.

Road connectivity, population, and crop production in Sub‐Saharan Africa

AbstractThis study adopts a cross‐sectional spatial approach to examine the relationship between transport infrastructure, population location, and agricultural production in Sub‐Saharan Africa using new data obtained from geographic information systems (GIS). We find that both population and agricultural production are spatially concentrated near large cities, with 41.4% of population and 23.6% of agricultural production (in value terms) within 2.5 hours travel time to large cities. Taking into account agroecological and other factors, we find a statistically significant association between travel time and agricultural production. Using coefficients estimated for Mozambique, we simulate the effects of hypothetical increases in road investments on travel times and agricultural production, suggesting that improvements in road infrastructure could facilitate a substantial increase in agricultural production.

Climate change and variability in Sub-Saharan Africa: a review of current and future trends and impacts on agriculture and food security

Sub-Saharan Africa has been portrayed as the most vulnerable region to the impacts of global climate change because of its reliance on agriculture which is highly sensitive to weather and climate variables such as temperature, precipitation, and light and extreme events and low capacity for adaptation. This article reviews evidence on the scope and nature of the climate change challenge; and assesses the impact of climate change on agriculture and food security in Sub-Saharan Africa. From the review, it is apparent that the climate in Africa is already exhibiting significant changes, evident by changes in average temperature, change in amount of rainfall and patterns and the prevalence of frequency and intensity of weather extremes. The review also revealed that although uncertainties exist with regards to the magnitude of impacts, climate will negatively affect agricultural production in Sub-Saharan Africa. Specifically, as result of current and expected climate change, the area suitable for agriculture, the length of growing seasons and yield potential, particularly along the margins of semi-arid and arid areas, are expected to decrease. These impacts will affect all components of food security: food availability, food accessibility, food utilisation and food stability and hence increase the risk of hunger in the region. The review thus confirms the general consensus that Sub-Saharan Africa is the most vulnerable region to climate change. It suggests that, policymakers and development agencies should focus on formulating and implementing policies and programmes that promote farm level adaptation strategies currently being practiced by farmers across the region.

Socio-Economic Factors Influencing Adoption Of Improved Fallow Practices Among Smallholder Farmers In Western Tanzania

Declining soil fertility is recognized as one of the major biophysical constraints affecting agricultural production in Sub-Saharan Africa. “Improved fallows” technology, a leguminous trees-based soil replenishment technology was introduced in smallholder farming system in Tanzania to address this problem. The objective of this study was to identify the factors that influence the adoption of the technology among smallholder farmers in Western Tanzania. The results revealed that lack of farmer awareness of the technology, inability of farmers to wait for two years before obtaining direct benefits from the technology were the major constraints to planting improved fallows. The study identifies farmer training through workshops and seminars, enforcement of village by-laws on animal grazing, and facilitation of farmers’ access to credit as the major approaches to enhance the adoption of the technology. Key words: Agroforestry, leguminous trees, soil fertility, sustainable agriculture, Tanzania.

Production and storage of N-enriched co-compost

Recovery of the organic fraction of municipal waste for peri-urban agriculture could contribute to the improvement of environmental sanitation and increase agricultural productivity in Sub-Saharan Africa. However, municipal waste co-compost (Co) has low nitrogen (N) content. Therefore, this study investigated the type and form of inorganic N fertiliser that is capable of improving the nitrogen content of Co and monitored the changes in the properties of this N-enriched product under storage. To attain 30,000 mg kg(-1) (3%) N content, different amounts of urea or ammonium sulphate were applied in various forms (dry, paste and liquid) to enrich Co. The product termed comlizer was stored and its moisture, pH, total nitrogen, NH(4)(+)-N, NO(3)(-)-N, and C/N ratio were monitored under ambient conditions for two years. In the first four months of storage, total N content of 50 kg Co+3.26 kg urea (CoUD) increased from 31,333 to 54,000 mg kg(-1), and 50 kg Co+7.14 kg (NH(4))(2)SO(4) (CoASD) from 35,333 to 52,000 mg kg(-1). At the end of two years of storage, the initial N content of CoUD and CoASD decreased by 47% and 24%, respectively. Based on these results, it is recommended that dry (NH(4))(2)SO(4) should be used in N enrichment of Co, and that the comlizer should be stored in sealed bags but not more than four months.

The impact of climatic change on agricultural production: Is it different for Africa?

This paper examines the impact of climatic change on the level of total agricultural production of Sub-Saharan Africa (SSA) and non-Sub-Sahara Africa (NSSA) developing countries. In doing so it uses a new cross-country panel climatic dataset in an agricultural production framework. The results show that climate, measured as changes in country-wide rainfall and temperature, has been a major determinant of agricultural production in SSA. In contrast, NSSA countries appear not to be affected by climate in the same manner. Simulations using the estimates suggest that the detrimental changes in climate since the 1960s can account for a substantial portion of the gap in agricultural production between SSA and the rest of the developing world.

User Acceptability of Sustainable Soil Fertility Technologies: Lessons from Farmers' Knowledge, Attitude and Practice in Southern Africa

ABSTRACT Low soil fertility is one of the greatest biophysical constraints to agricultural production in sub-Saharan Africa. “Improved fallow,” an agroforestry-based soil fertility replenishment technology was developed in response to the depletion of soil fertility and increasing difficulty of small-scale farmers to afford mineral fertilizers. The biophysical performance of the technology to improve soil fertility and increase crop yield has been well demonstrated and efforts are being made to enhance the adoption its adoption by farmers. There is relatively little information and systematic feedback regarding farmers' perception and knowledge of the technology. Using data collected from a stratified sample of 302 farmers in Zambia, this study analyzed farmers' knowledge, attitudes, and perceptions of soil fertility and food security problems, highlighting implications for user acceptability and the development of sustainable soil fertility management technologies. Results show that farmers have good understanding of soil fertility issues, its linkage to food security and household welfare indicators. They appreciate improved fallow because it responds to the critical problems of low soil fertility and provides additional benefits to the household. However, there are some challenges to the widespread uptake of the technology including land constraints, property rights availability of seeds, and knowledge-intensive nature of the technology. Farmer acceptability and improved adoption of the technology will be influenced by the extent to which efforts are taken to meet these challenges. Farmers' response on knowledge, attitude, and perception provides valuable inputs for further development and modification of the technology. Beyond technology development, an understanding of farmers' preference and other contextual issues-within which the technology is expected to be adopted-will enable researchers to develop appropriate sustainable technologies and enhance user acceptability of the same. The study shows that technical characteristics are important but not exclusive conditions for farmers' acceptability and adoption of good agricultural technologies by farmers.

Modelling of planted legume fallows in Western Kenya using WaNuLCAS. (I) Model calibration and validation

Poor soil fertility is the biggest obstacle to agricultural productivity in Sub-Saharan Africa. Improved fallows can help to raise agricultural productivity in these systems of low financial capital, however, experimental testing of their potential application domain and design is costly and time consuming. Models can evaluate alternative systems relatively quickly and at relatively low cost, but must first be validated to assess satisfactory simulation of the target systems. Specific climatic, edaphic, crop and fallow growth data was used from five sites in Western Kenya to calibrate and validate simulations of maize and improved fallow growth using the Water, Nutrient and Light Capture in Agroforestry Systems (WaNuLCAS) model. The model predicted continuous maize yields across the sites with an R 2 of 0.72, an EF (model efficiency) of 0.66 and a CD (coefficient of determination) of 2.73, although the default pedotransfer functions (PTF) for volumetric soil water content used in the model had to be substituted for a tropical soils specific PTF before this was achieved. Predicted maize yield was consistently related to fallow biomass (i.e. higher fallow biomass correlated with higher subsequent maize yields) at two sites and the model predicted maize yields following fallow growth from this subset of the data with an R 2 of 0.42. This relationship of fallow biomass to subsequent maize yield was not observed across the whole data set due to incomplete fallow litterfall data, factors not included in the model and associated poor model prediction of recycled tree biomass. After site and tree calibration, the model can thus be applied to assess fallow management strategies for sites limited by water and nitrogen.

Institutions and agricultural productivity in Sub-Saharan Africa

Agricultural productivity in 41 Sub-Saharan Africa (SSA) countries from 1960 to 1999 is examined by estimating a semi-nonparametric Fourier production frontier. Over the four decades the estimated rate of productivity change was 0.83% per year, although the average rate from 1985 to 1999 was a strong 1.90% per year. Former UK colonies exhibited significantly higher productivity gains than others, while Liberia and countries that had been colonies of Portugal or Belgium exhibited net reductions in productivity. We measure a significant reduction in productivity during political conflicts and wars, and a significant increase in productivity among those countries with higher levels of political rights and civil liberties.

Beyond adding up inputs and outputs: process assessment and upscaling in modelling nutrient flows

Departing from the historical background of scientific interest in soil fertility and sustainable agricultural production in sub-Saharan Africa, a review is conducted of nutrient budget studies carried out in semi-arid West Africa at scales ranging from individual fields to the sub-continent. For both, nitrogen and phosphorus, the comparison discloses largely diverging balances calculated for similar agro-ecosystems. In a first step, the modes of calculation of the nutrient budgets are examined. It is demonstrated that the calculations used in the different studies differ by the variables and biophysical processes taken into account, and by the choice of spatial scales as well as related time scales. One important discrepancy between approaches is whether and to which extent nutrient flows are internalized when upscaling. The extent to which the impact of individual and communal management, especially of pastoral and forestry resources, on nutrient flows is accounted for is a second cause of divergence. Moreover, it was observed that nutrient budgets tend to be increasingly negative as the spatial scale of the study increases from farm to sub-continent. This unexpected trend is traced back to the lack of internalization of nutrient flows when upscaling. The complexity of the scale patterns of nutrient flows and that of the interactions and the tradeoffs in the effects of management calls for the use of models to calculate nutrient budgets. Therefore, in a second step, examples of a static model, a multiple-goal linear programming model and a decision rules model were reviewed, all of which include the calculation of nutrient flows and balances and which were applied to West-African farming systems. The models are analyzed for their way of dealing with the critical issues of spatial and temporal scales and the impact of resource management on nutrient flows, taking into account that they have different objectives and were designed for different spatio-temporal scales. To conclude, suggestions were made for strengthening the use of models as tools enabling ex-ante testing of alternative agricultural technologies and policies that could improve soil nutrient balances in semi-arid sub-Saharan Africa.

Crop Rotation to Improve Agricultural Production in Sub-Saharan Africa

A three years' trial was conducted in a farmers' field in northern Ghana to evaluate the effect of sole crops (cotton, cowpea, groundnut, soybean, and sunflower) planted once or twice on yield of the staple foods of the region, maize and sorghum. Sole cropping for only one year already resulted in significant yield increases for maize and partly for sorghum compared to the conventional cropping of mixed stands of maize–sorghum or maize–groundnut and natural fallow. Lowest yield of maize and sorghum was obtained where these cereals followed maize–sorghum (monoculture). Intercropping of maize with groundnut led to subsequent maize and sorghum yields which were similar to those obtained after maize–sorghum. After growing legumes and sunflower for one year the grain and straw yield of maize and sorghum was significantly higher in the two consecutive years than after cereal (maize–sorghum) monoculture. In this trial maize and sorghum were found to be not as tolerant to the disadvantages of monoculture or preceding cereals–legumes mixture. The results suggest that continuous intercropping with cereals under the given conditions has negative effects on soil fertility and can lead to an increase in soil-borne pests and troublesome weeds like Striga comparable to monocropped cereals.

Appropriate transport and rural development in Makete district, Tanzania

Poor transport conditions are a substantial constraint on the increase of agricultural production in sub-Saharan Africa. Conventional rural transport projects, which focus exclusively on motorised transport, can only partly remove these restrictions. Therefore an appropriate transport approach is proposed, which also takes into account non-motorised transport. A field study in Makete District, Tanzania demonstrates that these interventions are at least as effective as rural road improvements.

The recovery of agricultural productivity in sub-Saharan Africa

This paper presents a new view of cross-country agricultural productivity in sub-Saharan Africa. For the first time, the “wheat units” approach to output aggregation is applied to Africa. This approach avoids many of the problems caused by exchange rate distortion and related problems when international output comparisons are based on agricultural value added. Measures of agricultural productivity based on the wheat unit aggregates reveal a striking recovery of growth in agricultural productivity during the mid-1980s. These results contrast sharply with those derived from standard output aggregates based on agricultural value added. This contrast is true for both partial and total factor productivity analyses. Technical change, measured by expenditures for agricultural research, and macroeconomic reform, which leads to improved economic incentives for agriculture, might account for up to two-thirds of this recovery. If this explanation is correct, it raises concerns for the sustainability of Africa's recent gains. Reduced public investment in agricultural research, for example, reduces current fiscal deficits at the expense of future growth in productivity.

Farmer Education and Farm Efficiency: A Survey

Development strategies increasingly emphasize agricultural development, employment, and equity; it is therefore important to examine the role of education in light of these new emphases. The purpose of this paper is to synthesize the conclusions of a number of studies of the effect of a farmer's educational level and exposure to extension services on his productivity. Eighteen studies conducted in low-income countries provided 37 sets of farm data that allow a statistical estimation of the effect of education. The overall conclusion of this paper is that farm productivity increases as a result of a farmer's completing at least 4 additional years of elementary education rather than none. Also, the effects of education were much more likely to be positive in modernizing agricultural environments than in traditional ones.