Exploring the potential of urban vertical farming : economic and technological analyses

Thesis (MScAgric)--Stellenbosch University, 2019.

ENGLISH ABSTRACT: Food security is defined as the situation in which all people are able to achieve access to sufficient, safe and nutritious food at all times in order to maintain a healthy and active lifestyle. Food security is based upon three pillars; food availability, food access and food use. The current situation of food insecurity that exists, particularly in developing nations is such that drastic measures need to be taken to resolve the perpetuating problem. An alternative to address this urgent need is the adoption of urban vertical greenhousing to ensure food insecurity becomes a problem of the past. Financial feasibility is crucial in understanding the potential success of a venture. On paper the production system may be best practise but if it is not profitable then it will not gain traction in the real world. In order to understand the financial feasibility of a greenhouse venture, an enterprise budget was constructed and various financial indicators were calculated. The enterprise budget was constructed from data collected from a single case study of a lettuce greenhouse producer situated in the Western Cape. This was a fully functional commercial greenhouse producing for the local market. Findings from the research suggest that the investment into a greenhouse venture is a financially viable option. Thus, the return on capital investment is sufficient for the greenhouse venture to be profitable within the short term as well as be sufficient to ensure that all borrowed capital will be paid back with ease. It also suggests that the venture will not encounter cash flow problems, an issue often encountered with large investments into farming production systems. However, it must be noted that this a single isolated case study. More research needs to be conducted as to understand if greenhouses can be financially feasible regardless of where they are implemented. on the natural ecosystem. A trial was conducted on the effectiveness of LED light as supplemental light as to improve the efficiency of urban vertical greenhousing. The trial took place using a hydroponic growth system in which lettuce plants were planted as seedlings and allowed to grow for 28 days. The trial was conducted under winter conditions in Stellenbosch. The lettuce plants were harvested and both quality measurements and nutrient analyses were taken to understand the effect that light quality (colour) and photoperiod had on lettuce growth. There were variable effects on growth and development of lettuce crop and with regards to nutritional qualities due to photoperiod duration and light quality. It was noteworthy that when giving supplemental light careful consideration should be taken as to the balance between the length of the photoperiod and light intensity. Supplemental light should always be given as to reflect natural seasonal patterns of light. Thus, when increasing the photoperiod, light intensity should also be increased, as to ensure that proper balance is maintained within the plant.

AFRIKAANSE OPSOMMING: Voedselsekuriteit word gedefinieer as die situasie waarin alle mense te alle tye toegang tot genoegsame, veilige en voedsame voedsel kan verkry ten einde 'n gesonde en aktiewe lewenstyl te handhaaf. Voedsel sekuriteit is gebaseer op drie pilare; voedsel beskikbaarheid, voedsel toegang en voedsel gebruik. Die huidige situasie van voedselonsekerheid wat bestaan, veral in ontwikkelende lande, is sodanig dat drastiese maatreëls getref moet word om die voortdurende probleem op te los. 'n Alternatief om hierdie dringende behoefte aan te spreek, is die aanneming van stedelike vertikale kweekhuise om te verseker dat voedselonsekerheid 'n probleem van die verlede word. Finansiële haalbaarheid is noodsaaklik om die potensiële sukses van 'n onderneming te verstaan. Op skrif kan die produksiestelsel die beste praktyk wees, maar as dit nie winsgewend is nie, sal dit nie traksie in die werklike wêreld kry nie.Ten einde die finansiële haalbaarheid van 'n kweekhuisonderneming te verstaan, is 'n ondernemingsbegroting opgestel en verskeie finansiële aanwysers is bereken. Die ondernemingsbegroting is opgebou uit data versamel uit 'n enkele gevallestudie van 'n blaarslaai-produsent in die Wes-Kaap. Dit was 'n ten volle funksionele kommersiële kweekhuis wat vir die plaaslike mark produseer. Bevindinge uit die navorsing dui daarop dat die belegging in 'n kweekhuis-onderneming 'n finansieel lewensvatbare opsie is. Die opbrengs op kapitale belegging is dus voldoende om die kweekhuisonderneming op kort termyn winsgewend te maak en voldoende om te verseker dat alle geleende kapitaal met gemak terugbetaal sal word. Dit dui ook daarop dat die onderneming nie kontantvloeiprobleme sal ondervind nie, 'n probleem wat dikwels met groot beleggings in boerderyproduksiestelsels voorkom. Daar moet egter gelet word dat dit 'n enkele gevallestudie is. Meer navorsing moet gedoen word om te verstaan of kweekhuise finansieel haalbaar is, ongeag waar hulle geïmplementeer word. Ten slotte is 'n proef gedoen met LED-lig as aanvullende lig om die doeltreffendheid van stedelike vertikale kweekhuise te verbeter. Die proef het plaasgevind met behulp van 'n hidroponiese groeistelsel waarin blaarslaai geplant is as saailinge en toegelaat was om vir 28 dae te groei. Die proef is onder wintertoestande in Stellenbosch gedoen. Die blaarslaai is geoes en beide gehaltemetings en voedings analises is geneem om die effek wat ligkwaliteit (kleur) en fotoperiode op blaarslaai het, te verstaan. Daar is bevind dat daar varieërbare effekte was op blaarseienskappe ten opsigte van beide die fotoperiode as ligkwaliteit. Dit was opmerklik dat wanneer die aanvullende lig verskaf word, dit in gedagte geneem moet word dat die balans tussen die lengte van die fotoperiode en die ligintensiteit belangrik is. Bykomende lig moet altyd gegee word om natuurlike seisoenale patrone van lig te weerspieël. Dus, wanneer die fotoperiode toeneem, moet ligintensiteit ook verhoog word, om te verseker dat behoorlike balans in die plant gehandhaaf word.

Masters