Posts Tagged ‘Africa’

The geography of Zambia’s customary land : assessing the prospects for smallholder development

Posted by gabrielamartinez on , in Journal Articles

57950Authors: Sitko, N.J. and Chamberlin, J.

Published in: Land Use Policy, 2016, vol.55, p.49-60


This article utilizes available spatial data to quantify the amount of customary land in Zambia and to examine the prospects for agricultural commercialization in those areas, in terms of population densities, market access conditions, and agro-ecological suitability. We find that approximately 51–54 percent of Zambia’s land remains under customary tenure and, by implication, available for smallholder utilization. However, populations are clustered in 5 percent of the customary land with reasonably good market access conditions. Good market access conditions are generally located in regions with high levels of rainfall variability due to historical infrastructure investments. High density, market accessible regions are witnessing a rapid increase in land commodification, land alienation, and declining fallow rates. Land and economic development policies must be attentive to the changing dynamics in customary land areas in order to ensure the future viability of the smallholder farming sector.

Crop residue allocation to livestock feed, soil improvement and other uses along a productivity gradient in Eastern Africa

Posted by gabrielamartinez on , in Journal Articles

57951Author(s): Duncan, A.J.; Bachewe, F.; Mekonnen, K.; Valbuena, D.; Rachier, G.; Lule, D.; Bahta, M.; Erenstein, O.

Published in: Agriculture, Ecosystems and Environment 2016, vol.228, p.101-110


Crop residues are a key livelihood resource in smallholder mixed crop-livestock systems in Sub-Saharan Africa. With expansion of arable land and resultant decline in grazing resources, crop residues are becoming an increasingly important component of livestock feeds. This demand for livestock feeds has implications for the long-term sustainability of such systems since failure to return biomass to soils has implications for soil quality and the capacity of soils to support long-term productivity. Biomass allocation patterns are likely to vary with overall level of productivity and hence availability. In this study we used a household survey to quantify crop residue allocation patterns across a gradient of productivity in Eastern Africa focusing on two sites in Ethiopia and one in Kenya. We assessed the underlying determinants of crop residue allocation patterns with a view to understanding how productivity increases through intensification will influence biomass allocation in Eastern Africa and how livelihood and natural resource management objectives could be optimized. Results showed that farmers strongly favour allocation of residues to livestock feeding but that allocation to soil increases along the productivity gradient. This reduced feeding to livestock and increased allocation to soil fertility is associated with smaller farm sizes leading to reduced animal traction needs for tillage, increased overall livestock productivity, increased use of inputs and a reduced reliance on farm-based activities in overall livelihood strategies. The implications of these trends are that productivity increases in smallholder systems are likely to reduce pressure on biomass in the long term and that measures that enhance the prospects for farmers to intensify their production systems are likely to increase soil health and sustainability objectives in general. A key conclusion of the work is that intensification of livestock production could reduce crop residue allocation to soils with long term implications for soil productivity.

Effects of relay cover crop planting date on their biomass and maize productivity in a sub-humid region of Zimbabwe under conservation agriculture

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57955Authors: Mhlanga, B.; Cheesman, S.; Maasdorp, B.; Mupangwa, W.; Munyoro, C.; Sithole, C.; Thierfelder, C.

Published in: NJAS Wageningen Journal of Life Sciences, 2016, vol.78, p.93–101.


Relay cropping of cover crops is a strategy of increasing biomass yields and productivity of maize-based systems. However, there is need to strategically plan the relay cropping to avoid competition between the main crop and the relay cover crops while at the same time obtaining optimum yields from both crops. A study was carried out in a clay soil in a sub-humid region of Zimbabwe to investigate the effect of introducing different relay cover crops at 8, 11 and 15 weeks after planting maize (WAPM) into a standing maize crop on biomass yield of the relay cover crops, their emergence and maize yields in the 2012–13 and 2013–14 seasons. From the results of the study, it was observed that the introduction of relay cover crops late in the season compromises their emergence and hence biomass yields (as low as 0.8 kg ha−1 for blue lupins (Lupinus angustifolius var. angustifolius (L.)). In a season where longer mid-season dry spells were experienced (2013–14), biomass yields of the relay cover crops were lower than in 2012–13 season. Delays in planting of relay cover crops (i.e. from 8 to 11 and from 11 to 15 WAPM) resulted in yield reductions of around 50%. Relay cover crops introduced at different periods of the season had no significant effects on maize grain and biomass yields. However, there are relay cover crops such as the velvet bean (Mucuna pruriens (L.) DC) and common oats (Avena sativa L.) that showed better emergence even in the sub-optimal conditions (with emergence as high as 90%). Of all the investigated relay cover crops, none could contribute to significant amounts of biomass thus insignificant increases in total plot biomass. There is need to investigate on other earlier planting dates that do not compromise the biomass productivity of such relay cover crops.

Fertilization strategies in Conservation Agriculture systems with Maize-Legume cover crops rotations in Southern Africa

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57956Author(s): Mupangwa, W.; Thierfelder, C.; Ngwira, A.

Published in: In: Experimental Agriculture In press


Multilocation experiments were established to determine the best strategy for using inorganic fertilizer in conservation agriculture (CA) systems that use green manure cover crops, namely sunhemp, velvet bean and cowpea grown in rotation with maize. The objectives of the study were to determine (i) the effect of half and full rates of basal fertilizer on maize and legume biomass yields, (ii) the residual effects of unfertilized, half and fully fertilized green manure legumes on maize grown after the legumes, and (iii) the residual effect of unfertilized, half and fully fertilized green manure legumes combined with basal and topdressing fertilizer on maize yields. Experimental design was a randomized complete block with basal fertilizer as a treatment in the green manure legumes phase. Previously, in the maize phase, green manure legume species were the main treatment with basal fertilizer as a subtreatment (sunhemp, velvet bean and cowpea: 0, 75, 150 kg ha−1 and 0, 50, 100 kg ha−1, respectively). Nitrogen was applied in the maize phase at 0, 23, 46, 69 kg N ha−1 as a sub-subtreatment in Malawi. Results showed that inorganic fertilizer is the most effective when applied to the maize, not green manure legumes. Biomass of green manure legumes, sunnhemp 8084 kg ha−1, velvet bean 7678 kg ha−1 and cowpea 4520 kg ha−1, was not significantly affected by application of basal fertilizer. Maize production increased after the application of green manure legumes with maize-after-maize, maize-after-velvet bean, maize-after-sunnhemp and maize-after-cowpea, yielding 3804, 5440, 5446 and 5339 kg ha−1, respectively. Nitrogen increased maize yield regardless of the previously used green manure legumes species. Our results suggest that farmers should apply fertilizer to maize and grow green manure legumes on residual soil in CA systems. Despite growing green manure legumes, smallholders should apply nitrogen topdressing to maize grown using the green manure legumes in some agro-ecologies.

Targeting drought-tolerant maize varieties in Southern Africa : a geospatial crop modeling approach using big data

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57959Authors: Kindie Tesfaye Fantaye.; Sonder, K.; Cairns, J.E.; Magorokosho, C.; Amsal Tesfaye Tarekegne; Kassie, G.; Getaneh, F.; Abdoulaye, T.; Tsedeke Abate; Erenstein, O.

In: The International Food and Agribusiness Management Review 2016, vol. 19 (Special Issue A), p.75-92


Maize is a major staple food crop in southern Africa and stress tolerant improved varieties have the potential to increase productivity, enhance livelihoods and reduce food insecurity.

This study uses big data in refining the geospatial targeting of new drought-tolerant (DT) maize varieties in Malawi, Mozambique, Zambia, and Zimbabwe. Results indicate that more than 1.0 million hectares (Mha) of maize in the study countries is exposed to a seasonal drought frequency exceeding 20% while an additional 1.6 Mha experience a drought occurrence of 10–20%. Spatial modeling indicates that new DT varieties could give a yield advantage of 5–40% over the commercial check variety across drought environments while crop management and input costs are kept equal. Results indicate a huge potential for DT maize seed production and marketing in the study countries. The study demonstrates how big data and analytical tools enhance the targeting and uptake of new agricultural technologies for boosting rural livelihoods, agribusiness development and food security in developing countries.

Kenyan Isolates of Puccinia graminis f. sp. tritici from 2008 to 2014 : virulence to SrTmp in the Ug99 race group and implications for breeding programs

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57963Authors: Newcomb, M.; Olivera Firpo, P.D.; Rouse, M.N.; Szabo, L.J.; Johnson, J.; Gale, S.; Luster, D.G.; Wanyera, R.; Macharia, G.; Bhavani, S.; Hodson, D.P.; Patpour, M.; Hovmoller, M.S.;Fetch, T.G.; Yue Jin.

Published in: American Phytopathological Society Phytopathology, 2016, vol. 106, no. 7, p.729-736.


Frequent emergence of new variants in the Puccinia graminis f. sp. tritici Ug99 race group in Kenya has made pathogen survey a priority. We analyzed 140 isolates from 78 P. graminis f. sp. tritici samples collected in Kenya between 2008 and 2014 and identified six races, including three not detected prior to 2013. Genotypic analysis of 20 isolates from 2013 and 2014 collections showed that the new races TTHST, TTKTK, and TTKTT belong to the Ug99 race group. International advanced breeding lines were evaluated against an isolate of TTKTT (Sr31, Sr24, and SrTmp virulence) at the seedling stage. From 169 advanced lines from Kenya, 23% of lines with resistance to races TTKSK and TTKST were susceptible to TTKTT and, from two North American regional nurseries, 44 and 91% of resistant lines were susceptible. Three lines with combined resistance genes were developed to facilitate pathogen monitoring and race identification. These results indicate the increasing virulence and variability in the Kenyan P. graminis f. sp. tritici population and reveal vulnerabilities of elite germplasm to new races.

Does closing knowledge gaps close yield gaps? On-farm conservation agriculture trials and adoption dynamics in three smallholder farming areas in Zimbabwe

Posted by gabrielamartinez on , in Journal Articles

57964Authors: Cheesman, S.; Andersson, J.A.; Frossard, E.

Published in: Journal of Agricultural Science, In press.


On-farm demonstration-trials are a common strategy to introduce new technologies to farmers, while simultaneously evaluating these technologies’ performance under farmer conditions. The current study focuses on conservation agriculture (CA) technology adoption dynamics among a small group of farmers who can be considered increasingly knowledgeable, as they have hosted CA demonstration-trials for at least 7 years. Management and performance of farmers’ fields were compared with the CA demonstration-trials implemented on the same farm, focusing on yield gaps (YGs) between the two and the uptake of CA or some of its principles. Comparisons were made between demonstration-trials and farmers’ fields in three distinct land classification areas: Madziwa Communal Area (est. 1910s), Chavakadzi (est. 1980s) and Hereford (est. 2000s) Resettlement Areas. It was found that closing knowledge gaps on CA did not close YGs and that CA adoption was partial. In the Communal Area, CA principles have barely been taken up, but farmer yields were often as good as on the demonstration-trials. In the Resettlement Areas, farmers did take up reduced tillage (CA principle 1) and practised rotations (CA principle 3), but not residue retention (CA principle 2). Rather than partial CA adoption, lower fertilization rates explained the recorded YGs in the Resettlement Areas. In the three areas, farmers’ interest in CA-based increasing of yields was limited, as circumstances drove them to embark on extensification rather than a land use intensification pathway.

The adoption problem; or why we still understand so little about technological change in African agriculture

Posted by gabrielamartinez on , in Journal Articles

57965Authors: Glover, D.; Sumberg, J.; Andersson, J.A.

Published in: Outlook on Agriculture, 2016, vol.45, no.1, p.3-6.


The notion of adoption is central to efforts to measure technological change in African agriculture, and plays an important role in the evaluation of return on investment in agricultural research and technology development. However, the adoption concept, as it is commonly used in both the literature and development research practice, is seriously flawed and leads to inaccurate and misleading conclusions. The authors outline a design specification for a replacement concept that would provide a better basis for robust empirical research on the economic, social and environmental impacts of investment in agricultural technology development and promotion. They propose that this new concept can contribute to a better and more nuanced understanding of the impacts of technology development interventions.

Ex ante welfare analysis of technological change: the case of nitrogen efficient maize for african soils

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56895Authors: Kostandini, G., La Rovere, R., Guo, Z.

Published in: Canadian Journal of Agricultural Economics, 2015, vol. 0, no. 0, p. 1-22


 

This study evaluates the potential impacts of the Improved Maize for African Soils (IMAS) project in two countries of Africa: Kenya and South Africa. The IMAS varieties offer significant yield advantages for regions where low or no fertilizer is used. The analysis uses spatial production data and household data to account for the level of fertilizer use in different agroecological zones of the country as well as different types of maize producing households. Results suggest that IMAS will deliver a total of US$586 million in gross benefits with US$136 million and US$100 million of benefits to producers in Kenya and South Africa, respectively, and an additional US$112 million to consumers in Kenya and US$238 million to consumers in South Africa. These benefits could help more than 1 million people escape poverty in the two countries by 2025. Household level results suggest that small households in areas with relatively low levels of fertilizer use stand to gain significant benefits.

Dans la présente étude, nous analysons les répercussions potentielles du projet Improved Maize for African Soils (IMAS – maïs amélioré pour les sols africains) dans deux pays africains : le Kenya et l’Afrique du Sud. Les variétés de maïs utilisées dans le cadre du projet IMAS offrent la possibilité d’accroitre considérablement les rendements dans les régions qui utilisent peu ou pas d’engrais. Dans le cadre de notre étude, nous avons utilisé des données spatiales sur la production et sur les ménages pour déterminer le taux d’utilisation d’engrais dans les zones agroécologiques de chaque pays ainsi que les divers types de ménages qui cultivent le maïs. Les résultats de notre étude autorisent à penser que le projet IMAS permettra de dégager des avantages bruts évalués à 586 M$ US, dont 136 M$ US et 100 M$ US pour les producteurs du Kenya et de l’Afrique du Sud respectivement, ainsi que 112 M$ US et 238 M$ US supplémentaires pour les consommateurs du Kenya et de l’Afrique du Sud respectivement. Ces avantages pourraient permettre à plus d’un million de personnes d’échapper à la pauvreté dans ces deux pays d’ici 2025. Les résultats à l’échelle des ménages semblent indiquer que les ménages de petite taille installés dans les zones où l’utilisation des engrais est assez faible sont plus susceptibles de tirer des avantages importants.

Big constraints or small returns? explaining nonadoption of hybrid maize in Tanzania

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56866Authors: Kathage, J.; Kassie, M.; Shiferaw, B.; Qaim, M.

Published in: Applied Economic Perspectives and Policy, 0(0): 1–19, 2015.


 

New technologies are often not widely adopted by farmers in Africa. Several adoption constraints have been discussed in the literature, including limited access to information. Using data from maize farmers in Tanzania, we challenge the hypothesis that limited information is an important constraint for hybrid seed adoption.

While we find an adoption gap from lack of hybrid awareness, this gap is sizeable only in regions where productivity gains of hybrids are small. Hence, awareness of a new technology may be a function of expected returns. Other constraints related to assets and credit are not significant.We conclude that not adopting a technology is not always a sign of constraints but may also indicate low benefits from its use.