Smallholder food security impacts of industrial crop expansion and land use change in Malawi: a system dynamics simulation

Read, Matthew James (2018-03)

Thesis (MEng)--Stellenbosch University, 2018.

Thesis

ENGLISH ABSTRACT: Food security is still a pervasive problem, nowhere more so than in sub-Saharan Africa (SSA). Industrial crop (IC) expansion has been at the centre of a debate as to whether ICs are assisting or hindering the quest for a more food secure future. These conflicting views, outlined in a review of pertinent literature, highlight the need for further study into the topic. A review of the literature revealed that food security in the context of SSA is a complex issue and a function of integrated social, economic, and physical systems. To understand this complex system better, it is proposed that a computer-based model is constructed to simulate the dynamics of the system. Models that simulate food security or food security related issues were therefore reviewed and the absence of a simulation that modelled food security from the household level perspective was uncovered. Various modelling attributes and techniques were subsequently reviewed, and system dynamics was chosen as the most appropriate modelling methodology to tackle the research problem under consideration in this study. The software package Vensim was selected as the modelling medium. For the development of the model, Malawi was identified as a suitable country to serve as the case study for this research inquiry. A conceptual model was created explaining the system feedbacks observed in Malawi through causal loop diagrams. The formal simulation was then developed from the conceptual model. It was found that the cultivation of ICs contribute to food security in Malawi. This is largely the result of increased credit options available to smallholder farmers who engage in IC cultivation. Smallholders who cultivate multiple crops are generally more food secure than those who monocrop in cases where limited land is available. This is because mixed-crop farmers are less vulnerable to climate variability. In some cases, mixed cropping leads to staggered income sources and expenses, this reduces the amount of time between harvests and leads to briefer episodes of food shortages overall. Cassava, a plant resilient to extreme weather conditions, is an important food crop in combatting food insecurity. Tobacco, a high-value crop which is well suited to climatic conditions in much of Malawi, remains a lucrative option for smallholder farmers. Contractual agreements between leaf companies, sugar millers, and smallholder farmers could, however, be improved. It is recommended that a regional-level model is developed to capture the effects of higher level system dynamics on smallholder farmers to be used in conjunction with this model. Keywords: food security; industrial crops; computer modelling; Malawi; system dynamics

AFRIKAANSE OPSOMMING: Voedselsekuriteit is steeds 'n algemene probleem, veral in sub-Sahara Afrika (SSA). Uitbreiding van industriële gewasse (IG) was die middelpunt van 'n debat wat gehandel het oor die vraag of IGs die soeke na 'n veiliger toekoms vir voedsel kan bevorder of verhinder. Hierdie teenstrydige standpunte, soos uiteengesit in 'n oorsig van toepaslike literatuur, beklemtoon die behoefte aan verdere studies wat handel oor hierdie onderwerp. 'n Hersiening van die literatuur het getoon dat voedselsekuriteit in die konteks van SSA 'n komplekse kwessie is, en 'n funksie van geïntegreerde sosiale-, ekonomiese- en fisiesestelsels is. Om hierdie komplekse stelsel beter te verstaan, word voorgestel dat 'n rekenaargebaseerde model ontwikkel word om die dinamika van die stelsel te simuleer. Modelle wat voedselsekuriteit of voedselsekuriteits verwante kwessies simuleer, is hersien en die afwesigheid van 'n simulasie wat voedselversekering en voedselsekuriteit vanuit die huishoudelike-vlak perspektief modelleer, is ontbloot. Verskeie modelleringseienskappe en -tegnieke is hersien, en stelseldinamika is gekies as die toepaslike modelleringsmetodologie. Die sagtewarepakket Vensim is gekies as die modelleringsmedium. Vir die ontwikkeling van die model is Malawi as geskikte land geïdentifiseer om as gevallestudie vir hierdie navorsingsondersoek te dien. 'n Konseptuelemodel is geskep wat die stelsel terugvoering wat in Malawi waargeneem word, deur middel van oorsaaklike lusdiagram, verduidelik. Die formele simulasie is dan uit die konseptuele model ontwikkel. Daar is bevind dat die verbouing van IGs bydra tot voedselsekuriteit in Malawi. Dit is hoofsaaklik as gevolg van die groter hoeveelheid kredietopsies wat beskikbaar is vir kleinhoewe-boere wat betrokke is by IG-verbouing. Kleinhoewe-boere wat veelvuldige gewasse verbou, is meer voedselveilig as diegene wat slegs enkele gewasse verbou in gevalle waar beperkte grond beskikbaar is. Die rede hiervoor is omdat boere wat gemengde-gewas boerderye bedryf minder vatbaar vir klimaatsverandering is. In sommige gevalle lei gemengde gewasverbouing tot gesteierde inkomstebronne en uitgawes, wat gevolglik die inkomstegaping tussen oeste verminder en ook lei tot korter voedseltekort episodes. Cassava, 'n plant wat veerkragtig is vir uiterste weerstoestande, word beskou as 'n belangrike voedselgewas in die bestryding van voedselonsekerheid. Tabak, 'n hoë waarde-oes wat goed by die klimaatstoestande in Malawi pas, bly 'n winsgewende opsie vir kleinboere. Kontrakooreenkomste tussen blaarmaatskappye, suikermolers en kleinboere kan egter verbeter word. Daar word aanbeveel dat 'n streeksvlakmodel ontwikkel word om die effekte van hoërvlak-stelseldinamika op kleinboere te verstaan en dat so ‘n hoë-vlak model gebruik word saam met die model wat in hierdie studie ontwikkel is.

Please refer to this item in SUNScholar by using the following persistent URL: http://hdl.handle.net/10019.1/103455
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