Without an increase in cropland, agricultural efficiency must be tripled in the next 50 years to sustain the increased demand for food. Controlled environment agriculture (CEA) systems are likely to play an important role in the increase of agricultural efficiency. CEA systems, however, require constant observation because decisions must be quickly made when plants show signs of stress. A visual inspection system that uses a robotic camera system would permit visual access to inaccessible plants in a large hydroponics operation or allows an observer to remotely inspect plants for multiple small or remote CEA operations, whereas a dedicated CEA specialist would be beneficial but impractical under present conditions. This thesis presents a theoretical design for a plant inspection robot. The design parameters, design process, and the system specification necessary to satisfy the design constraints were examined for this system. The design analysis revealed that the major components of the plant inspection robot must be designed sequentially, starting with the imaging system. The imaging system design revealed that the system parameters were governed by illumination, shape and size of the object, and the desired detail. The motion system design was governed by velocity, acceleration, work area, and accuracy. An example design for a system used for visual inspection of 289 romaine lettuce plants was presented. This design was shown to be feasible from the theoretical perspective and could be built from commercially-available components, reducing development time and cost.

Production and consumption of edible berries are increasing rapidly in the United States, mostly due to their superior flavor profile, and popular diet-related value with their human health relevant bioactives and nutritional benefits. However, bioactive and nutritional qualities, especially human health protective phenolic antioxidants and associated non-communicable chronic disease (NCD) relevant health benefits of berries vary widely among accessions/cultivars and due to different production practices (organic vs conventional). Therefore, the aim of this thesis was to screen and select high phenolic and high antioxidant serviceberry and blackberry accessions/cultivars and to investigate the effect of different weed management and fertilization (organic vs. conventional) practices on phenolic bioactive linked antioxidant and anti-diabetic properties of blackberry using in vitro assay models. Overall, high phenolic-bioactive linked antioxidant and anti-hyperglycemic properties were observed in both serviceberry and blackberry accessions/cultivars and further for blackberry it was significantly higher under organic weed management and fertilization practices.

Wissenschaftler sind weltweit bereits seit geraumer Zeit darum bemüht, Lösungen für die praktikable Umsetzung einer urbanen Produktion frischer Gemüse zu erarbeiten. Die hydroponischer Anbauverfahren haben ein überdurchschnittlich hohes Potential, wenn es um die Einsparung von Produktionsmitteln geht. So können im Pflanzenbau gegenüber dem Freilandanbau bis zu 90 Prozent des eingesetzten Wassers durch geschlossene Kreisläufe eingespart werden. Diese Kreisläufe vermeiden zudem den Eintrag von Düngemittel in die Umwelt. Der geschützte Anbau in Hochhäusern sorgt für ein optimales Pflanzenwachstum ohne ungünstige Witterungseinflüsse. So ist nicht nur eine sichere marktnahe Produktion gewährleistet, es kann auch das ganze Jahr hindurch produziert werden. Transporte von Produkten aus weit entfernten Gegenden anderer Länder können somit vermieden werden. Hinzu kommt die Flächenersparnis und die damit hohe Flächenproduktivität führen. Dennoch zeigen erste Umsetzungsversuche auf, dass es noch einen hohen Grad an Forschungs- und Entwicklungsarbeit bedarf bis eine profitable Lösung für den Markt bereit steht. Insbesondere der hohe technische Aufwand und Energiebedarf erster Testanlagen sind hier als besondere Herausforderung anzusehen. In dem umfassend angelegten Forschungs- und Entwicklungsvorhaben mit dem Namen BrickBorn Farming – Nahrungsmittelproduktion in Gebäuden städtischer Gebiete sollen verschiedenste Aspekte weiterentwickelt und miteinander verknüpft werden.

Problem Statement: The world population is expected to rapidly increase, raising food security concerns across the world. This will impact Africa most severely. The use of innovative farming techniques and technology has proven to accelerate the production yields and improve resilience to vulnerabilities which impact agricultural productivity. The use of smart technologies in farming is mainly present among largescale commercial farms, with minimal representation in the smallholder farming sector. On the other hand, a substantial amount of food in developing countries is produced by small scale farmers. Research Objective: The purpose of the study is to investigate the usage of smart technologies by smallholder farmers in South Africa, and to establish how smart technology could support smallholder farmers in increasing productivity through a three-dimensional view that takes into consideration capital, labour, and land utilization. To this end, an interpretive research philosophy was adopted. Research Design: The study collected the data using semi-structured interviews. The sample for the study constituted of 10 smallholder farmers and 12 subject matter experts within the agriculture and technology domain. To strengthen rigour within the study, the interviews were supported by documents containing viewpoints about how technology is applied in the African context and how it may be introduced and ultimately applied in the South African context. The study employed a deductive approach to theory, applying the Sustainable Livelihoods Approach (SLA) as theoretical underpinning for the study. SLA consists of a pentagon of livelihood assets: physical, social, human, natural, and financial assets. The framework was extended to include technology as an asset due to its potential to contribute to improving the livelihoods of smallholder farmers. Findings: The study found minimal to no use of smart technologies by smallholder farmers in South Africa. The factors which limited the use of technology include PEST (Political, Environmental, Social and Technological) factors. To achieve successful usage of smart technologies, collaboration is required from government, the private sector, smallholder farmers, and communities. Research Contribution: The study aimed to expand on the limited literature on the use of smart farming in the context of smallholder farmers in a developing country context. In addition, it contributed to extending the pentagon of livelihoods to include smart technologies with respect to smallholder farmer livelihoods. Therefore, the findings of this study contributed to the broader body of knowledge. In addition, insights from this study may be gained by the Department of Agriculture, Forestry and Fisheries, smallholder farmers, agricultural entrepreneurs and technologists in formulate developmental strategies and policies to improve the productivity of smallholder farmers as well as their livelihoods as a strategy to increase their contribution to food security in Africa while alleviating household poverty.

No description available.

No description available.

Thesis (M. A. (Sociology)) -- University of Limpopo, 2017 / The study explored Mutoko community members’ perceptions of climate change and its impact on subsistence farming. Mutoko is a rural community situated in the eastern part of Zimbabwe. Focus group discussions were conducted to explore perceptions of climate change and its impacts on subsistence farming. The study findings show that the primary source of food is subsistence farming. The main crop grown in Mutoko is maize, followed by ground nuts (peanuts), and indigenous vegetables. Maize, ground nuts, sunflowers (for seed), sorghum and millet are grown for household consumption. The study reports community members’ perceptions and views of changes in the local natural environment. The changes are increased temperature and scarcity of rain. Observable impacts of these changes are decreased crop yields in times of drought. The findings are supported by observation that Zimbabwe lies in a semi-arid region with limited and unreliable rainfall patterns and temperature variations. Rainfall exhibits considerable spatial and temporal variability. Generally, the impact of climate change on subsistence farming was the major concern among the participants. Though the study was not aimed at documenting adaptation measures taken to lessen the negative impacts of increased temperature and rainfall scarcity on crop production, the study shows that adaptive measures have been developed and used to adapt and cope with climate change. Community members are adapting to the impacts of increased temperature and scarcity of rain through their culturally informed mechanisms. The mechanisms include change of crops, use of manure to improve soil structure and mulching. It is concluded that the impact of climate change on subsistence farming is real and is negatively affecting food security in the study area. Farmers gave different views on the following; knowledge about climate variations, changes in environmental conditions, changes in temperature patterns and changes in rainfall patterns. / Centre of Indigenous Knowledge Systems (CIKS) and National Research Foundation (NRF)

<p>Vertical farming (VF) as a newer sector of controlled-environment agriculture (CEA) is proliferating as demand for year-round, local, fresh produce is rising. However, there are concerns regarding the high capital expenses and significant operational expenses that contribute to fragile profitability of the VF industry. Enhancing resource-use efficiency is a strategy to improve profitability of the VF industry, and different approaches are proposed in the three chapters of this dissertation. LEDs are used for sole-source lighting in VF, and although they recently have significantly improved electrical efficiency and photon efficacy, the Lambertian design of the illumination pattern leads to significant loss of obliquely emitted photons beyond cropping areas. In chapter 1, close-canopy lighting (CCL) is proposed as one effective energy-saving strategy, through which unique physical properties of LEDs were leveraged, and two CCL strategies (energy efficiency and yield enhancement) were characterized at four different separation distances between light-emitting and light-absorbing surfaces. Dimming to the same light intensity at all separation distances resulted in the same biomass production while significant energy savings occurred at closer distances. Significantly higher light intensity and yield were achieved under closer separation distances in the yield-enhancement strategy for the same energy input. The energy-utilization efficiency (g fresh/dry biomass per kWh of energy) was doubled in both scenarios when the separation distance between LED emitting surface and crop surface was reduced maximally. At reduced separation distances, the chance of photon escape from growth areas is less, and canopy photon capture efficiency is improved.</p><p>Optimizing environmental conditions for indoor plant production also helps improve resource-use efficiency for the nascent vertical-farming industry. Although significant technical advancements of LEDs have been made, use of efficient far-red (FR) LEDs has yet to be exploited. As a recent proposed extension to traditional photosynthetically active radiation (PAR, 400-700 nm), FR radiation (700-750 nm) contributes to photosynthesis as well as photomorphogenesis when added to shorter wavelengths of traditional PAR. However, the interaction of FR with other environmental parameters such as CO2 is less studied. In chapter 2, the interaction effect of four FR fluxes (as substitution for red) in combination with three different CO2 concentrations were investigated at three distinctive stages of young-lettuce production. The highest biomass achieved at all stages occurred at 800 mmol mol-1 CO2 compared to 400 and 1600 mmol mol-1. A photomorphogenic effect of FR to promote leaf length was pronounced at the earliest stages of development, at which FR did not contribute to higher biomass accumulation. At more developed stages, 20 mmol m-2 s-1 of FR substituting for red contributed to biomass accumulation similar to shorter wavelengths of traditional PAR, whereas higher fluxes of FR in the light recipe resulted in undesirable quality attributes such as longer leaves.</p><p>Optimizing environmental conditions for indoor production with emphasis on light intensity and CO2 concentration at four distinctive stages of lettuce production was investigated in chapter 3. Utilizing the Minitron III gas-exchange system, light and CO2 dose-response profiles were characterized at four distinctive crop-development stages through instantaneous gas-exchange measurements at crop level. At all developmental stages, as CO2 concentration increased, photosynthesis increased up to 500 mmol mol-1, above which the incremental rate of photosynthesis was reduced. Light-dose response profiles were characterized at 400 or 800 mmol mol-1 CO2, and as light intensity increased, photosynthesis increased up to 650 mmol m-2 s-1. However, when instantaneous power (Watts) consumed for lighting was taken into consideration, power-use efficiency as the ratio of output photosynthesis increment to input power increment (to increase light intensity), decreased at higher light intensities. Vertical farming as a nascent and growing industry is facing limitations including marginal and even elusive profitability. Optimizing environmental conditions for indoor plant production such as these will help improve resource-use efficiency and profitability of the vertical farming industry.</p>

A procedure that determines the economic feasibility of irrigation and determines the instantaneous pumping demand and seasonal water use of feasible irrigation systems was developed. A 54 year (1930-1983) precipitation record was used to determine the future probability of drought occurring in a specific location under a given set of conditions in Virginia. Econometric models developed by Taylor, et al. (1985) were used to conduct the economic analysis. Econometric models for various ranges for center pivot, traveling gun, big gun, and portable pipe irrigation systems were utilized in the procedure. The developed procedure was applied to the Pamunkey River area in Eastern Virginia. Projections on cumulative irrigated acreage, pumping capacity, and seasonal water use were produced. / M.S.

Thesis (PhD(Agric) (Agricultural Economics))--University of Stellenbosch, 2011. / ENGLISH ABSTRACT: This dissertation is an analysis of dairy production in the Midlands district of KwaZulu-Natal. The analysis of agricultural production generally ignores undesirable outputs that are produced alongside desirable outputs. This research attempted to integrate a model of nitrate leaching from dairy production into a multiple input/output representation of the production technology, together with the analysis of technical efficiency. Estimation of both technical efficiency and environmental efficiency were done following the parametric econometric stochastic frontier (SFA) and the nonparametric mathematical programming data envelopment analysis (DEA) approaches. The study used unbalanced panel data from 37 individual highly specialized dairy farms for the period 2000 to 2007 and totals to 2130 observations. Production functions for the three outputs; milk, animals and farm produced feed, were fitted as a simultaneous system to model the farms’ production activities for the econometric SFA estimation of technical efficiency. A single equation reduced form was fitted as a frontier to allow for the estimation of the relative efficiencies of the individual farms. The results showed that with data this detailed it was possible to refine the model until it fits very tightly. Indeed, in the gross output model that includes cows, there was nothing left to call inefficiency and what was clearly a frontier becomes a mean response function. Technical efficiency was further calculated using the nonparametric DEA approach using the same dataset. The estimation of environmental efficiency was done using both SFA and DEA approaches. Undesirable emissions of nitrate were represented within the models by calculating nitrogen surplus (kg/ha) for each farm. This nitrogen surplus value was based on the intensity of the use of nitrogen containing inputs and the nitrogen content of marketable products specific information and from farm data which were used to calculate a farm nitrogen balance. The stochastic estimation of environmental efficiency used the same data that were used for the estimation of technical efficiency. However, for the DEA calculation of environmental efficiency, a balanced cross-section dataset for 34 farms participating in a pasture-utilization programme was used. This dataset was used because it had quantities of nitrogen fertilizer and other nitrogen containing inputs. Results indicate that there was minimal “over-usage” (over production) of milk thus reducing milk output alone will not lead to improved environmental efficiency. Farm size, herd size, and quantity of nitrogen fertilizer applied, present the best scope of reducing nitrogen surplus thus improving environmental efficiency of the dairy farms. Reducing imported feed by relying more on home grown feed can also help reduce nitrogen surplus. This is feasible because dairy farmers in the KwaZulu-Natal Midlands can produce most of the feed on farm. In summary, to obtain environmental efficiency milk production would have to be reduced by 80 litres per hectare; farm size by 73.69 ha; herd size by 33 cows, nitrogen fertilizer application by 74.3 kilograms per hectare; and imported feed by 13.4 kilograms of dry matter per hectare. The adjustments that would be required if environmentally inefficient farms were to adopt best practice technology and move towards their environmental production frontiers indicate that the production of pollutants (nitrogen surplus) could be reduced at negligible cost to milk production. The positive correlation between technical and environmental efficiencies indicates that improving environmental efficiency could be associated with improvements in technical efficiency. Thus, policies aimed at improving both efficiencies could have substantial rewards. / AFRIKAANSE OPSOMMING: In hierdie tesis word suiwelproduksie in die Middellande van KwaZulu-Natal van nader beskou. Met die ontleding van landbouproduksie, word ongewenste uitsette wat saam met gewenste uitsette geproduseer word, gewoonlik oor die hoof gesien. Hierdie navorsing poog om ’n model van nitraatvrylating uit suiwelproduksie in ’n veelvuldige inset/uitset verteenwoordiging van die produksietegnologie, te integreer by die analise van tegniese doeltreffendheid. In opvolging van die benaderings tot die parametriese ekonometriese stogastiese front (SFA) en die omvattingsanalise ten opsigte van die nie-parametriese matematiese programmeringsdata, is beramings van sowel tegniese as omgewings doeltreffendheid gedoen. In die studie is gebruik gemaak van paneeldata van 37 individuele hoogs gespesialiseerde melkplase vir die tydperk 2000 tot 2007, wat altesaam 2130 waarnemings beloop. Produksiewerksaamhede vir die drie uitsette; melkproduksie en diere- en plaasgeproduseerde voer, is as ’n gelyklopende stelsel ingepas om die plase se produksiewerksaamhede vir die ekonometriese SFA-beramings van tegniese doeltreffendheid weer te gee. ’n Enkele vorm om gelykmaking te verminder is daargestel as ’n front vir die beraming van die relatiewe doeltreffendhede van die individuele plase. Die resultate het bewys dat data van hierdie omvang dit moontlik maak om die model sodanig te verfyn dat dit net-net inpas. By die bruto uitset-model waarby koeie ingesluit is, was daar inderdaad niks wat op ondoeltreffendheid gedui het nie en wat eers ’n duidelike front was, het ’n betekenisvolle responsfunksie geword. Voorts is tegniese doeltreffendheid bereken deur aanwending van die nie-parametriese DEAbenadering, deur gebruik te maak van dieselfde datastel. Die beraming van omgewingsdoeltreffendheid is gedoen deur gebruikmaking van sowel SFA- as DEA-benaderings. Ongewenste nitraatvrylatings is in die modelle gevind deur die stikstofsurplus vir elke plaas te bereken (kg/ha) Die waarde van hierdie stikstofsurplus is gebaseer op die intensiteit van die gebruik van stikstofbevattende insette en bepaalde inligting oor die stikstof-inhoud van bemarkbare produkte, sowel as van plaas data, wat gebruik is om ’n stikstofbalans vir die plaas te bereken. Dieselfde data wat aangewend is vir die beraming van tegniese doeltreffendheid, is gebruik om die stogastiese beraming van omgewingsdoeltreffendheid te bepaal. Vir die DEA-berekening van omgewingsxii doeltreffendheid, is egter ’n gebalanseerde kruisseksie datastel gebruik vir 34 plase wat aan ’n weidingsbenuttings-program deelgeneem het. Die bepaalde datastel is gebruik omdat dit dosisse stikstofbemestingstof en ander stikstofbevattende insette bevat het. Resultate het op minimale “oorgebruik” (oorproduksie) van melk gedui en daarom sal die vermindering van slegs die melkuitset nie lei tot verbeterde omgewingsdoeltreffendheid nie. Plaasgrootte, kuddegrootte en die dosis stikstof wat toegedien is, verskaf die beste beeld van verminderde stikstofsurplus, wat dus tot verbeterde omgewingsdoeltreffendheid op melkplase lei. Die vermindering van ingevoerde voer deur meer op plaasgeproduseerde voer staat te maak, kan ook meewerk om stikstofsurplus te laat daal. Dit kan gedoen word omdat melkboere in die Middellande van KwaZulu-Natal die meeste van die voer op die plaas kan produseer. Ter samevatting kan gesê word dat om omgewingsdoeltreffendheid te bereik moet melkproduksie met 80 liter per hektaar verminder word, plaasgrootte met 73.69 ha, kuddegrootte met 33 koeie, stikstofbemestingtoediening met 74.3 kilogram per hektaar en ingevoerde voer met 13.4 kilogram droë materiaal per hektaar. Die aanpassings wat nodig sal wees indien omgewingsdoeltreffende plase beste praktyk-tegnologie sou aanvaar en sou aanbeweeg na hulle omgewingsproduksiefronte, dui daarop dat die produksie van besoedelende stowwe (stikstofsurplus) verminder kan word teen geringe koste aan melkproduksie. Die positiewe verband tussen tegniese en omgewingsdoeltreffendhede, dui daarop dat die verbetering van omgewingsdoeltreffendheid, in verband gebring kan word met verbeterings in tegniese doeltreffendheid. Beleid wat op verbetering van beide doeltreffendhede gemik is, kan daarom aanmerklike voordele inhou.