National Research Institutions

AquaCrop is a crop model that simulates yield response to water developed by FAO and is appropriate to consider effects where water is the limiting factor for crop production. AquaCrop was calibrated for amaranthus (Amaranthus cruentus L. ex Arusha), a leafy vegetable, and taro (Colocasia esculenta (L.) Schott.), a wetland perennial, with an edible starchy corm as a tuber crop. The weather datasets were obtained from the climate database at Agricultural Research Council-Institute of Soil, Climate and Water in Pretoria for specific sites and years of the trials. The first step in the model is to select the correct type of crop, create a new crop and name it. Observed soil parameters from the experimental sites were used to create soil files in AquaCrop; the model is sensitive to amount of water available in the soil between field capacity and permanent wilting point. The crop parameters under optimal water availability were adjusted according to observations from field trials conducted for each crop. The first parameter checked was canopy cover, representing the expansion of the leaf canopy under non-limiting conditions, where the maximum value, CCx, (90% for amaranthus and 78% for taro) and the time take to reach CCx were needed. The total length of the cropping season should be checked and also time to the start of senescence. However, for the leafy vegetable this was not necessary as the crop was harvested while the leaves were green. The effect of water stress must be included via the Ks factor for water stress according to stomatal closure at a specific soil water availability, as measured in the field trials. The water productivity normalised for ETo and CO2 concentration (32 g m-2 for amaranthus and 15 g m-2 for taro) was calculated from field data of biomass accumulation and transpiration standardised for ETo. The reference harvest index (HIo) was 85% for amaranthus and 83% taro, respectively. Once the model is calibrated with data from single sites, it must be verified with independent data from different sites and/or series of experiments. The calibrated AquaCrop model will be used to promote the introduction of these underutilised vegetables on irrigation schemes since optimal irrigation strategies can be developed. Best management practices, soil types, sowing dates and locations can be selected from model runs at a range of sites.

Intercropping involves the cultivation of two or more crops on the same field in both space and time. It is a farming practice that has existed throughout history and one which mimics natural diversity. Intercropping has several advantages over monocropping which include improved resource utilization of light, water and nutrients, as well as yield stability over time. It is a practice that historically contributed towards food security within communities. It offers a sustainable alternative to the more widely practiced monocropping. However, it has been widely regarded as a primitive practice and this has created a scenario whereby there was scant research done on intercropping. 

Successful crop stand establishment, a critical prerequisite for efficient crop production, is primarily determined by propagule quality. Taro [C%casia escu/enta (L.) Schott] corms of different sizes (80-100 g corm-1, 40-60 g corm-1 and 20-30 9 corm-1) that had been stored in soil pits at different depths (10,20,30,40 and 50 cm) were compared for stand establishment, leaf area and yield during two seasons, under rainfed (upland) conditions. Propagule size and pre-planting storage depth increased both the number of plants reaching the third leaf stage and leaf area per plant one month after planting. The large propagules improved stand establishment and yield significantly (P<0.01) better than the smaller propagules. For a” propagule sizes, the optimum storage depth to enhance taro propagule performance for crop production was – 40 cm. When the large propagules were compared with the smaller propagules at the optimum pre-planting storage depth, there was 10% to 30%, no difference and 5% to 35% improvement il’) leaf area, stand establishment and yield, respectively. This study confirmed the potential role of local knowledge in traditional agriculture, and the findings can be used to extend the planting season for dryland taro production in South Africa.

We would like to acknowledge the contributions of the Mechal team towards the process that led to the writing of this handbook. Special thanks go to Demamu Mesfin, Yosef Melka, Katinka Waagsaether, Donna Kotze, Estholene Moses, Emily Olsen, Daleen Lötter, Gina Ziervogel, Mark Tadross, Habtemariam Kassa, Kebede Kassa, Penny Price and Mark New.

We would also like to thank the community members in South Africa (Suid Bokkeveld and Goedverwacht) and Ethiopia (Arsi Negelle) for freely sharing their knowledge and insights.

This publication was made possible through a grant by the Volkswagen Foundation (Mechal Project under the Reference number I/83 735, co-ordinated by the University of Hamburg) with partners from South Africa (University of Cape Town, CSIR, Indigo development and change, Environmental Monitoring Group) and Ethiopia (Wondo Genet College of Forestry and Natural Resources, Hawassa University, Center for International Forestry Research (CIFOR).

SASSCAL is a joint initiative of Angola, Botswana, Namibia, South Africa, Zambia, and Germany, responding to the challenges of global change. The establishment of a Southern African Science Service Centre for Climate Change and Adaptive Land Management could create added value for the whole southern African region. It should be conceptualised and operationalised to complement the excellent existing research and capacity development infrastructures and research initiatives in the region. It should be embedded in the regional and national research. Its mission is to conduct problem-oriented research in the area of adaptation to climate change and sustainable land management and provide evidence-based advice for all decision-makers and stakeholders to improve the livelihoods of people in the region and to contribute to the creation of an African knowledge-based society.

A review of pesticide regulations and a summary of registered pesticides. Key findings:

• There are 158 registered active ingredients, incl. 49 HHP
• In the groundnut and soybean value chain best practice approaches to pest managements are already being practiced
• Increased pest monitoring, biopesiticides, improved and resistant varieties can support more effective pest management
• Need for awareness-raising among farmers and advisers on pest identification
• Policy-level support to incentivise the use of less toxic pesticides and increase availability and use of safer alternatives

Este é o 2o volume de uma coleção de histórias do Secretariado da SADC informando os cidadãos da SADC e criando consciência sobre impactos positivos dos protocolos, acordos, políticas e estrategias. A ambição é de ilustrar precisamente como os programmas de integração regional da SADC mudam as vidas dos cidadãos da SADC para o melhor. Para destacar alguns, no rio Zambezi, está em construção a Ponte Kazungula que vai em breve formar uma maior ligação no coração da região SADC. Em Malawi tem o tomate Bvumbwe, evoluído para responder às condições específicas da região e às demandas da população da SADC. Em Walvis Bay, Namibia, e Nacala, Mozambique, existem dois pontos de entrada para a rede crescendo de corridores de desenvolvimento, justapostos, qual a região SADC quer desenvolver na próximas decadas. 

Il s'agit du deuxième volume d'un recueil d'histoires du Secrétariat de la SADC visant à informer les citoyens de la SADC et à les sensibiliser davantage aux impacts positifs des protocoles, accords, politiques et stratégies de la SADC.  Il cherche à brosser un tableau précis de la manière dont les programmes d'intégration régionale de la SADC changent pour le mieux la vie des citoyens de la SADC. Pour n'en citer que quelques-uns, au Zambèze, il y a la construction du pont de Kazungula, qui constituera bientôt une importante liaison de transport au cœur de la région de la SADC. Au Malawi, il y a la tomate de Bvumbwe, qui a été développée pour répondre aux conditions spécifiques de cette région et aux besoins de la population de la SADC.  Et dans la baie de Walvis en Namibie et à Nacala au Mozambique, il y a deux points d'entrée au réseau croissant de corridors de développement le long desquels la région SADC se développera dans les décennies à venir.

This is the 2nd volume of a collection of stories by SADC Secretariat to inform SADC citizens and enhance awareness about the positive impacts of SADC  protocols, agreements, policies and strategies.  It seeks to paint an accurate picture of how SADC regional integration programmes are changing the lives of SADC citizens for the better. Just to highlight a few, at the Zambezi River, there is the construction of the Kazungula Bridge that will soon form a major transport link in the heart of the SADC region. In Malawi, there is the Bvumbwe tomato, which was developed to address the specific conditions of this region and the needs of the SADC population.  And in Namibia’s Walvis Bay and Mozambique’s Nacala, there are two entry points to the growing network of development corridors alongside which the SADC region will develop in the coming decades.

North-central Namibia is more vulnerable to effects of climate change and variability. Combined effects of environmental degradation, social vulnerability to poverty and a changing climate will compromise subsistence farming in north-central Namibia (NCN). This will make subsistence and small-scale farmers in the region more vulnerable to projected changes in the climate system. Thus, the aim of this article was to examine factors contributing to subsistence farmers’ vulnerability to impacts of climate change. The article further discusses different aspects of human vulnerability and existing adaptation strategies in response to impacts of climate related disasters experienced over the past three to four decades in NCN. Qualitative and quantitative research approaches and methodology were employed to obtain information from subsistence farmers in north-central Namibia. The sociodemographic characteristics of Ohangwena, Oshana and Omusati Region reveals high levels of unemployment, high adult and elderly population and high dependency on agricultural livelihood system. These indicators help understand levels of household vulnerability. The study concludes that households interviewed revealed low levels of adaptive capacity due to exposure to climate risks and combined effects of social, political and cultural factors. This article provided an understanding that is required to inform the adaptation pathways relevant for NCN.