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Calibration of AquaCrop Model to predict water requirements of African vegetables

Date of Publication
Oct 01, 2013
Description/Abstract

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.

Author or Institution as Author
S. Walker
Co-authors

Z.A. Bello, T. Mabhaudhi, A.T. Modi , Y.G. Beletse, G. Zuma-Netshiukhwi

Institution
International Society for Horticultural Science
Language
Category
Resource Type

Intercropping taro and bambara groundnut

Date of Publication
Oct 01, 2014
Description/Abstract

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. 

Author or Institution as Author
T. Mabhaudhi
Co-authors

A.T. Modi

Language
Category
Resource Type
Citation

Andrew DJ, Kassam AH (1975) The importance of multicropping in increasing world food supplies. In: Papendic RI, Sanchez PA, Triplet GP (eds) Multiple cropping, Special publication27. American Society of Agronomy, Madison, p 10

Azam-Ali SN (2010) Fitting underutilised crops within research-poor environments: lessons and approaches. S Afr J Plant Soil 27:293–298

Azam-Ali SN, Matthews RB, Williams JH, Peacock JM (1990) Light use, water uptake and perfor-mance of individual components of sorghum groundnut intercrop. Exp Agric 26:413–427

Baldy C, Stigter CJ (1997) Agrometeorology of multiple cropping in warm climates. Science Publishers, Enfield, p 237

Barhom THI (2001) Studies on water requirements for some crops under different cropping sys-tems. MSc thesis, Facility of Agriculture Cairo University

Baye T, Kebede H, Belete K (2001) Agronomic evaluation of Vernonia galamensis germplasmcollected from Eastern Ethiopia. Ind Crops Prod 14:179–190

Black C, Chin Ong C (2000) Utilisation of light and water in tropical agriculture. Agric For Meteorol 104:25–47

da Silva EE, de Azevedo PHS, Almeida MMTB, De-Polli H, Guerra J (2008) Influence of inter-cropping and irrigation frequency in the leaf development and taro (Cocoyam) productivity under organic management. 16th IFOAM organic world congress, Modena, 16–20 June 2008. Archived at http://orgprints.org/12595

(PDF) Intercropping Taro and Bambara Groundnut. Available from: https://www.researchgate.net/publication/261107954_Intercropping_Taro_a… [accessed Oct 24 2018].

Global Climate Change Impacts in Namibia

Date of Publication
Oct 01, 2012
Description/Abstract

The impact of global warming to the Namibian economy is enormous and already costs the government billions. Nevertheless the changing conditions also bear opportunities and potentials for growth, development and economic stability.

 

Author or Institution as Author
Bastian Köhler
Institution
Konrad Adenauer Stiftung
Language
Resource Type
Citation

Bastian Köhler, 2012. Global Climate Change Impacts in Namibia. Konrad Adenauer Stiftung.

Five Namibian communities holistically adapt to climate change

Date of Publication
Oct 01, 2015
Description/Abstract

Namibia is plagued with a dry climate and poor soils, and the country’s small-scale farmers produce the lowest agricultural yields in the world. With an estimated population of around two million, Namibia has the world’s second lowest population density. As global climate change impacts become more evident, Namibia is likely to be one of the most severely affected areas.

The Community Based Adaptation (CBA) project areas were located in Northern Namibia and consisted of five regions: Omusati, Ohangwena, Oshikoto, Oshana and Kavango. The majority of the community members were subsistence farmers who depended highly on rain-fed dry land crops and livestock rearing both for subsistence and income generation.

Climate change induced rising temperatures, irregular rainfall, prolonged and intensified drought and flood incidents have resulted in food and water insecurity, threatening the communities’ livelihoods, especially those of the marginalized groups within the communities: women and orphaned children from HIV/AIDS-affected families.

Author or Institution as Author
Anna Lisa Jose
Institution
UNDP
Language
Resource Type
Citation

Anna Lisa Jose, 2015. Five Namibian communities holistically adapt to climate change. UNDP.

Adaptation of agriculture to climate change in Northern Namibia

Date of Publication
Oct 01, 2015
Description/Abstract

Namibia is the driest sub-Saharan nation and is among the countries most severely affected by climate change. This is threatening food security, particularly in Namibia’s densely populated northern region, where more than half of the country’s 2.1 million residents live. The main activity in this region is subsistence agriculture, which is primarily rainfed. Older people are often left to carry out the agricultural work, while the younger generation moves to urban areas.

Both crop production and livestock farming are characterised by low levels of productivity. In the case of crop production and the main crops of millet and corn, this is primarily due to infertile soil and unreliable rainfall patterns. Where possible, farmers apply shifting cultivation practices and periodically clear new areas. Since organic and mineral fertilisers are rarely used, soil fertility rapidly diminishes. A number of small-scale farmers irrigate their fields, but the potential for irrigated agriculture is limited; in addition, this is a very capital-intensive method.

Due to climate change, additional productivity losses are expected in the region. Crop production, in particular, is already being affected by climate change. Temperatures and rainfall variability are increasing rapidly, and droughts and floods are becoming more and more frequent. By 2050, it is anticipated that it will only be possible to practise rainfed agriculture using current methods in Kavango East and Zambezi.

Despite the crop losses that are already associated with climate change, very few small-scale farmers are applying climate-adapted cultivation methods.

Author or Institution as Author
Namibia
Institution
GIZ
Language
Resource Type
Citation

GIZ, 2015. Adaptation of agriculture to climate change in Northern Namibia.

Namibia Signs Paris Agreement on Climate Change

Date of Publication
Nov 01, 2015
Description/Abstract

H.E Dr. Hage G. Geingob, President of the Republic of Namibia signed the Paris Agreement on behalf of Namibia at the signing ceremony at the U.N head Quarters in New York Yesterday (22 April 2016). A historic total of 171 Members signed the agreement on the same day. It is for the first time that the United Nations receives such a big number of signatories on the 1st day.

I believe this agreement will help us as a country to tackle the challenges of climate change and to capitalize on opportunities that will lead to sustainable development of our nation.

Furthermore, we are excited as Namibia to be part of this journey where as we pledged to play our part to reduce gas emmissions by 89% by 2030 as stipulated in our Intended Nationally Determined Contributions (INDC) document we submitted to the UNFCCC in 2015.

I am sure that all of us will agree that tackling the issue of climate change is crucial for Namibia condsidering how vulnerable our country is to climate change.

The Paris Agreement commits developed countries to take the lead in scaling up financial support for tackling climate change in developing countries.

In this regard, Namibia being a signatory to the Paris Agreement it has an opportunity to access such funding through institutions like recently operationalized Green Climate Fund.

The fund will assit the country is tackling climate change related challenges such as water insecurity; food insecurity and energy insecurity.

Author or Institution as Author
Travel News Namibia
Institution
Namibia
Language
Resource Type
Citation

United Nations, 2015. Namibia Signs Paris Agreement on Climate Change.

Effect of indigenous storage method on performance of taro [Colocasia esculenta (L.) Schott] under field conditions in a warm subtropical area

Date of Publication
Jan 01, 2013
Description/Abstract

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.

Author or Institution as Author
Modi, Albert T
Language
Category
Resource Type
Citation

T. MABHAUDHI, A. T. MODI. (2015) DROUGHT TOLERANCE OF SELECTED SOUTH AFRICAN TARO (COLOCASIA ESCULENTA L. SCHOTT) LANDRACES. Experimental Agriculture 51:03, pages 451-466.

Tafadzwanashe Mabhaudhi, Albert T. Modi, Yacob G. Beletse. (2014) Parameterisation and evaluation of the FAO-AquaCrop model for a South African taro (Colocasia esculenta L. Schott) landrace. Agricultural and Forest Meteorology 192-193, pages 132-139.

Gender and Climate Change: Namibia Case Study

Date of Publication
May 01, 2010
Description/Abstract

There is a strong relationship between gender, livelihood and poverty. This relationship has been explored by many researchers, and significant to their findings is the relationship between climate change and people’s livelihood, which is dependent on natural resource base and poverty.

Author or Institution as Author
Margaret Angula
Institution
FANRPAN
Language
Resource Type
Citation

Margaret Angula, 5/2010. Gender and Climate Change: Namibia Case Study.

Measuring adaptive capacity among local organisations

Date of Publication
Oct 01, 2015
Description/Abstract

The study focused on the NDM as a first step:

Mixed research approach to collect quanDtaDve and qualitaDve data through interviews conducted with small organisaDons (15 NGOs, 8 CBOs and 7 governmental units) idenDfied as potenDal applicants to the SGF project in the NDM

Aim:

1) to assess adapDve capaciDes among local organisaDons before the SGF project starts;

2) to idenDfy gaps in terms of knowledge and understanding of what CCA is ;

3) To inform facilitating agencies about needs for capacity buildings

Follow-up interviews will be conducted during the course of the SGF project to track progress in adapDve capacity and observe concrete impacts in terms of enhanced adapDve capacity among local organisaDons

Author or Institution as Author
Marie-Ange Baudoin
Language
Category
Resource Type

Participatory Adaptation Handbook

Date of Publication
Oct 01, 2018
Description/Abstract

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).

Author or Institution as Author
Noel Oettle
Co-authors

Bettina Koelle, Stephen Law, Shannon Parring, Ute Schmiedel, Emma Archer van Garderen, Tsegaye Bekele

Language
Category
Resource Type
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