Browsing by Author "Tumbo, Siza"

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Assessing the impacts of climate variability and change on agricultural systems in Eastern Africa while enhancing the region’s capacity to undertake integrated assessment of vulnerabilities to future changes in climate
(ICRISAT, 2015-02) Sanga, C; Sumari, Neema; Tumbo, Siza; Mourice, Sixbert K; Kadigi, Ibrahim; Kahimba, Frederick
One of the key messages emerging out of the recent IPCC reports is that the climate change is real, happening and will continue to happen for the foreseeable future , irrespective of what happens to future greenhouse gas emissions . The report also estimates wi th high confidence that the negative impacts on agriculture outweigh the positives which makes adaptation an urgent and pressing challenge. However, adaptation planning requires accurate information about where, when and how the impacts are going to be fel t and who will be more vulnerable. Among the regions, Africa is considered as more vulnerable due to its high dependence on agriculture for subsistence, employment and income. In Eastern Africa, agriculture accounts for 43% of GDP and contributes to more than 80% employment (Omano et al. 20 06). Within Africa, Eastern Africa is one of the most vulnerable regions due to its high dependence on rain - fed agriculture for subsistence, employment and income. The region experiences high variability in rainfall (Webster et al., 1999, Hastenrath et al. , 2007) which has a direct bearing on the performance of agriculture. Generally the region experiences prolonged and highly destructive droughts covering large areas at least once every decade and more localized events even more frequently. The region reco rded severe droughts and/or famines in 1973 - 74, 1984 - 85, 1987, 1992 - 94, 1999 - 2000, 2005 - 2006 and more recently in 2010 - 11. According to UNDP (2006), a single drought event in a 12 - year period will lower GDP by 7% – 10% and increase poverty by 12% – 14%. Extrem e events, including floods and droughts, are becoming increasingly frequent and severe (IPCC 2007). Based on the analysis of data from the international Disaster Database (EM - DAT), Shongwe et al. (2009) concluded that there has been an increase in the numb er of reported disasters in the region, from an average of less than 3 events per year in the 1980s to over 7 events per year in the 1990s and 10 events per year from 2000 to 2006. The negative impacts of climate are not limited to the years with extreme c limatic conditions. Even with normal rainfall, the countries in the region do not produce enough food to meet their people’s needs. Left unmanaged, these impacts can have far - reaching consequences on the local food security, economy, and poverty. Over the past few years, climate research has contributed significantly to increased understanding of how the climate in the region is var ying on inter - annual and decadal time scales and on how the climate is changing in response to global warming and other factors . The impacts of this variability and changes in climate on various sectors including agriculture have also received considerable attention . These studies indicate that a griculture, especially the one practiced under rainfed conditions in moisture limiting environments such as semi - arid tropics , is one of the most vulnerable sectors since these are relatively warmer places and rainfall is the only source of water. There is a rapidly growing literature on vulnerability and adaptation to climatic variability and change , but most of these studies are based on assessments made using statistical and empirical models that fail to account for the full range of complex interactions and their effects on agricultural systems (Parry et al., 2004; Cline, 2007; Lobell e t al., 2008). Evidence available to date indicate s that w ith 1°C of warming, roughly 65% of current maize growing areas in Africa will experience yield losses (Lobell et al., 2011) and the average predicted production loss es by 2050 for most crops are in t he ra n ge of 10 - 25% (Schlenker and Lobell, 2010) . For developing and implementing adaptation programs, more detailed information about the impacts of climate change on various components of the smallholder farming systems such as which crops and varieties are more vulnerable and which management practices are unviable is required . This requires a comprehensive assessment using site and location specific climate and crop management information. However, s everal problems constrain such an assessment. Firstly, downscaled local level climate change projections that are required to make such assessments are not readily available . While climate models provide various scenarios with high levels of confidence at global and sub - regional level, there are challenges in downscaling them to local level (IPCC, 2007) . Secondly, lack of information on the sensitivity of smallholder agricultural systems to changes in climate . Though process based crop simulation models can serve as important tools to make a more realistic assessment of impacts of climate variability and change on agricultural systems, application of the same is limited to few location specific studies mainly because of the intensive data requirements and practical limitations including capaci ty to calibrate, validate and perform detailed analyses. Thirdly, there is scarcity of information on how the impacts of climate change on the production and productivity of agriculture translate into economic impacts including food security at household a nd national levels. This assessment is aimed at developing more accurate information on how the projected changes in climate impact the productivity and profitability of agricultural systems that are widely adopted by smallholder farmers in Eastern Africa using the protocols and methods developed by Agricultural Model Intercomparision and Improvement Project (AgMIP) (Rosenzweig et al., 2013) . One key aspect of this assessment is the attention paid to captur e the complexity and diversity that exists in the s mallholder farm ing systems including the different ways in which th e system is managed. The study is an attempt to make a comprehensive assessment of climate change on crop growth and performance under conditions that interactions as well as related economic impacts by integrat ing state of the art downscal ed climate scenarios with crop and economic models. Th e assessment was carried out in contrasting agro - ecological zones spread over the four major countries in eastern Africa – Ethiopia, Keny a, Tanzania and Uganda. This report summarizes the findings that include trends and changes in the observed and downscaled climate scenarios, quantified information on impacts of these trends and changes on performance of maize under a range of environment al and management conditions, implication of these changes in crop performance on in come, poverty and food security of smallholder farmers and potential adaptation strategies that can assist smallholder farmers in minimizing negative impacts .
Experts’ assignment algorithm for Cloud-based Agro-advisory Service Information System (CASIS) using weighted sum model: piloting CASIS
(UbuntuNet Alliance, 2015) Fue, Kadeghe G; Tumbo, Siza; Sanga, C
A Cloud-based Agro-advisory Service Information System (CASIS) uses interactive operating mode where assignment of questions from farmers to experts is done manually. Questions as input to the system are received randomly in a day and experts are supposed to respond within a specified time. The system has 20 experts in its database who respond to farmers questions and it can receive more than 30 questions per day. If there is a significant delay in the responses to a question then the question is reassigned to another expert. Each expert behaves differently when responding to their assigned questions. In order to address the shortcomings, the experts’ assignment algorithm was developed utilizing the respondents’ response probabilities and time of responses. Assignment decision is based on using a model that trains ‘CASIS’ on the determination of best experts. CASIS training algorithm is developed to complement current weakness. The algorithm doesn’t omit experts who respond late but complements them with active ones. The decision boundary is homogeneity and numerical so as to give a single output quickly. The input (x1, x2) and output (y) variables are numeric. The main concept is that the output is generated using linear combination or weighted sum model The algorithm considers response time as best criteria to satisfy the farmers who send the questions. This algorithm provides a great chance of finding a quick answer within a short period of time. Automatic expert assignment is essential to achieve high adoption of the system that satisfies the on-time farmer advisories demand and promote efficiency as well as effective extension services for rural development.
Farmers' Access and Use of Mobile Phones for Improving the Coverage of Agricultural Extension Service: A Case of Kilosa District, Tanzania
(IGI Global, 2016-08) Sanga, Camilius; Mlozi, Prof M R S; Tumbo, Siza; Haug, Ruth
This study sought to investigate on the access and use of mobile phones for improving the coverage of agricultural extension services among farmers in the pre-harvest stages of maize value chain in Kilosa district. The study examined the use of mobile phones as a means for improving the coverage of agricultural extension services. The study adapted a cross sectional study design and a multistage sampling technique. Data were mainly collected using structured questionnaires. The results revealed that majority of respondents used mobile phones and had a positive attitude on the contribution of mobile phone in their farming business. The study results also indicated that mobile phones offered an affordable solution to farmers’ information needs and information requirements. The study concluded that the use of mobile phone to communicate agricultural information depends on information needs of farmers. The study recommended that farmers need to be encouraged and supported to access and use mobile phones in their farming business
Impacts of climate change on agriculture: What, when, where and how?
(2015) Tumbo, Siza; Sanga, C
One of the key messages emerging out of the recent IPCC reports is that the climate change is real, happening and will continue to happen for the foreseeable future. The report also estimates with high confidence that the negative impacts on agriculture outweigh the positives which makes adaptation an urgent and pressing challenge. However, adaptation planning requires accurate information about where, when and how the impacts are going to be felt and who will be more vulnerable. Eastern Africa is considered as one of the most vulnerable regions in the world due to its high dependence on agriculture for subsistence, employment and income. Generally the region experiences prolonged and highly destructive droughts covering large areas at least once every decade and more localized events more frequently. The negative impacts of climate are not limited to the years with extreme climatic conditions. Even with normal rainfall, the countries in the region do not produce enough food to meet their needs. Overlaid on this challenging scenario is the dominance of semi-arid to arid climatic conditions which are marginal for crop production, degraded soils, extreme poverty and lack of infrastructure which make the countries in the region highly vulnerable to current and future changes in climate. There is a rapidly growing literature on vulnerability and adaptation to increased climatic variability and change but most of these assessments are based on statistical and empirical models that fail to account the full range of complex interactions and their effects on agricultural systems. For developing and implementing adaptation programs, more detailed information about how the components of the prevailing farming system such as which crops and varieties are more vulnerable and which management practices are unviable under the predicted climates is needed. However, several problems such as non-availability of downscaled local level climate change projections, lack of information on how the projected changes impact agricultural systems and scarcity of information on how these changes on production and productivity of agriculture translate into economic impacts including food security at household and national levels are constraining such an assessment.
Mobile learning bridging the gap in agricultural extension service delivery: Experiences from Sokoine University of Agriculture, Tanzania
(International Journal of Education and Development using Information and Communication Technology, 2016) Sanga, Camilius; Mlozi, Malongo; Haug, Ruth; Tumbo, Siza
The ubiquitous nature of mobile phones offers a noble environment where farmers can learn informally anywhere, anytime and at any location. This is an innovative way to address some of the weakness of conventional agricultural extension service. Few empirical studies have reported on the development of mobile phone application to support blended learning for smallholder farming communities in developing countries. This study adopted a participatory action research method to develop innovative communication pathways in dissemination of agricultural information, agricultural knowledge and proven agricultural technologies from either extension agents or agricultural research centres or universities to farmers. The respondents who tested the system were selected random from 19 villages in Kilosa District, Tanzania. The developed systems support blended learning using mobile learning (m-learning) and electronic learning (e-learning). The findings from this study show that the systems can provide innovative mobile agricultural extension service to more than 380 smallholder farmers via web- and mobile-phone-based farmers’ advisory information systems.
Yield and soil system changes from conservation tillage in dryland farming: A case study from North Eastern Tanzania
(Elsevier, 2010-04-07) Enfors, Elin; Barron, Jennie; Makurira, Hodson; Rockström, Johan; Tumbo, Siza
Yield levels in smallholder farming systems in semi-arid sub-Saharan Africa are generally low. Water shortage in the root zone during critical crop development stages is a fundamental constraining factor. While there is ample evidence to show that conservation tillage can promote soil health, it has recently been suggested that the main benefit in semi-arid farming systems may in fact be an in situ water harvest- ing effect. In this paper we present the result from an on-farm conservation tillage experiment (combining ripping with mulch and manure application) that was carried out in North Eastern Tanzania from 2005 to 2008. Special attention was given to the effects of the tested treatment on the capacity of the soil to retain moisture. The tested conservation treatment only had a clear yield increasing effect during one of the six experimental seasons (maize grain yields increased by 41%, and biomass by 65%), and this was a season that received exceptional amounts of rainfall (549 mm). While the other seasons provided mixed results, there seemed to be an increasing yield gap between the conservation tillage treatment and the control towards the end of the experiment, and cumulatively the yield increased with 17%. Regarding soil system changes, small but significant effects on chemical and microbiological properties, but not on physical properties, were observed. This raises questions about the suggested water harvesting effect and its potential to contribute to stabilized yield levels under semi-arid conditions. We conclude that, at least in a shorter time perspective, the tested type of conservation tillage seems to boost productivity during already good seasons, rather than stabilize harvests during poor rainfall seasons. Highlighting the challenges involved in upgrading these farming systems, we discuss the potential contribution of con- servation tillage towards improved water availability in the crop root zone in a longer term perspective.