A portable dual-camera video system was used to evaluate the potential for using total projected green cover as an indirect measure of weed infestations in a wheat crop during early growth stages. The video system would have applications in mapping weed infestations to assist precision farming operations. <p>The two cameras provided a real-time composite image of reflected light measured in red (640 nm), and near-infrared (860 nm) wavelengths. A simple ratio of reflected light intensity in each wavelength was used to isolate the growing plants from the background. Software was developed to automatically adjust for varying ambient light conditions and calculate the percentage of the image occupied by growing plants. Total green cover was measured at randomly selected sites prior to direct seeding wheat and at four growth stages following wheat emergence. The portion of green cover observed was compared to crop and weed dry matter at each location. Weed infestations at each location were estimated by measuring the total green cover and subtracting the projected green cover due to the crop alone. A minimum weed dry matter of 20 g/m2 and 30 g/m2 could be detected by the video system at the 3-leaf and 5-leaf growth stages, respectively. Weed dry matter less than 20 g/m2 could not be detected reliably due to the variability of the wheat crop. Detection of weeds within the crop beyond the 5-leaf stage using this method was difficult due to crop canopy closure.

As food scares have hastened the growth of safety and quality standards around the world, certification schemes to assure various attributes of foods have proliferated in the global marketplace. High-value food commodities produced in the global south for export have been the subject of such schemes through third-party environmental certifications, providing regulatory and verification mechanisms welcomed by global buyers. As certification becomes more common, re-localization in the current global context can also mean the projection of place onto a food commodity to highlight its origin or attributes secured by transparent verification mechanisms. However, environmental food certification is often criticized for its inapplicability in the context of the global south, due to the extensive documentation requirements and high costs. The key question here is the process for small-scale producers in the global south to navigate increasing international regulation of food safety and quality. This dissertation examines (1) how the environmental standards (as defined by the global north) were translated in the rural global south through international certification schemes, and (2) what the implications are at the local level, especially where producers had not yet integrated into conventional global markets before the introduction of certification. The dissertation also analyzes the influence of such certification in determining the development trajectories of rural society in the global south. A case study is used to examine newly-introduced certified organic shrimp production in Ca Mau Province in Vietnam’s Mekong Delta. The selected shrimp production site is the first pilot organic shrimp project in Vietnam working with an international third-party certification scheme. It is located in rural Vietnam where, as in other parts of Southeast Asia, an accelerated process of agrarian transition is underway. Whereas elsewhere the trend with intensified regulation has been the consolidation of large-scale farms and the exclusion of small-scale farms from international agrofood markets, this case study demonstrates comparative advantages of small-scale farms over large-scale farms in producing sensitive high-value crops. This dissertation employs two main analytical approaches. The first approach is to examine the network of actors and the flow of information, payment and shrimp at the production level using environmental regulatory network (ERN). In contrast to chain analyses, which can be useful in identifying linear structure of supply chains for global commodities, ERN can capture the interrelatedeness of actors in the network built around environmental certification for agrofood products. The second analytical lens is that of agrarian transition. Countries experiencing agrarian transition at present are doing so in a very different international context from countries that accomplished their transitions in the past. Results of this research indicate that technical and financial constraints at the time of initial certification are not the primary obstacles to farmers getting certified, since the extensive farming method employed at the study site is organic by default. In spite of this, many farmers unofficially withdrew from the organic shrimp project by simply shifting their marketing channel back to a conventional one. Inefficient flows of information and payments, and a restrictive marketing channel within the environmental regulatory network that does not take into account local geographical conditions and farming practices, all contributed to limiting the farmers’ capacity and lowering their incentives to get involved in the network. The analysis also indicates that, by influencing those agrarian transition processes, food standards and certification based on values developed in the global north may modify, reshape and/or hold back agrarian transition processes in agricultural sectors of developing countries. The potential benefits of environmental certification are enhanced rural development, by generating opportunities for small-scale farmers to connect to global niche markets. The findings of this dissertation highlighted that such certification schemes or their environmental regulatory networks need to ensure information sharing and compensation for farmers. As an empirical finding, this dissertation also captures where ecological credibility and market logic meet: the success of this kind of certification depends on finding a balanced point where standards are ecologically (or ethically) credible to the level that does not attract too much criticism for being green washing, but not too unrealistic to become a disincentive for farmers to participate.

The purpose of this research was to investigate how sustainable agriculture is being conceptualized and implemented in Saskatchewan. Zero tillage, organic farming, and the discourses surrounding them were examined as theoretical and practical responses to sustainable agriculture. Characteristics of 33 organic and 33 zero tillage farming systems located throughout the soil climatic zones of southern Saskatchewan were compared, as well as farmers' perceptions of sustainable agriculture and factors influencing their management decisions. The analysis was extended beyond the local level by examining the links between major socio-political forces shaping agriculture and farmers' perceptions and choices. Central to this analysis is an examination of the role of informal and formal knowledge systems in the development of sustainable agriculture, and how relations of power affect the knowledge that is being produced and ultimately the direction of change in agriculture. Interdisciplinary and exploratory approaches were used to identify and examine a range of emergent issues. The data gathered was analyzed both quantitatively and qualitatively. This study revealed commonalities between zero tillage and organic farmers' basic views on sustainable agriculture, and important differences in the ways these two groups of farmers translated these ideas into practice. Most farmers defined sustainability at the farm-level, focusing on land stewardship and the preservation of the family farm. Farmers adopted zero tillage because of specific environmental, economic and labour advantages, whereas organic farming was adopted for a combination of environmental, health, economic, philosophical/spiritual and labour factors. In general, zero tillage and organic farming systems differed in size, in production and management operations, in land tenure, and in the use of purchased inputs and labour. Zero tillage farms tended to be large, capital-intensive, specialized cropping operations, with a significant proportion of rented land and non-family hired labour. Organic farms were moderate-sized, diversified crop and livestock operations that substituted biological and cultural practices for purchased (agrochemical) inputs, had a high degree of ownership, and relied more upon labour exchange. These characteristics create distinct environmental, economic and social advantages and disadvantages. Zero tillage, compatible with the dominant agricultural paradigm and the industrial model, continues to be promoted by agricultural institutions and agribusiness as the best solution to farm-level sustainability. Interest in organic agriculture and the alternative agricultural paradigm is increasing, however, due to the current crisis in the farm economy and changes in consumers' perceptions and choices.

A portable dual-camera video system was used to evaluate the potential for using total projected green cover as an indirect measure of weed infestations in a wheat crop during early growth stages. The video system would have applications in mapping weed infestations to assist precision farming operations. <p>The two cameras provided a real-time composite image of reflected light measured in red (640 nm), and near-infrared (860 nm) wavelengths. A simple ratio of reflected light intensity in each wavelength was used to isolate the growing plants from the background. Software was developed to automatically adjust for varying ambient light conditions and calculate the percentage of the image occupied by growing plants. Total green cover was measured at randomly selected sites prior to direct seeding wheat and at four growth stages following wheat emergence. The portion of green cover observed was compared to crop and weed dry matter at each location. Weed infestations at each location were estimated by measuring the total green cover and subtracting the projected green cover due to the crop alone. A minimum weed dry matter of 20 g/m2 and 30 g/m2 could be detected by the video system at the 3-leaf and 5-leaf growth stages, respectively. Weed dry matter less than 20 g/m2 could not be detected reliably due to the variability of the wheat crop. Detection of weeds within the crop beyond the 5-leaf stage using this method was difficult due to crop canopy closure.

Thesis (M. Arch.)--University of Hong Kong, 1996. / Includes bibliographical references.

This thesis focused on the conversion period from conventional to organic agriculture for a Quebec dairy farm. The crucial problem resided in developing an economic framework to evaluate alternative crop rotations that would provide farmers in transition an optimal rotation plan compatible with organic farming practices. / Two multi-period linear programming models were developed for that purpose, both models having different assumptions concerning effects that the transition might have on crop yield. / In both transitional models, two crop rotations were selected in the optimal solution. In addition, the establishment of crop rotations was comparable for both models, and this showed that the assumed drop in yield did not have a large impact on the selection of crop rotation. Also, the results support the notion that conversion to organic agriculture had a relatively less negative effect on farm profit if the transition was done gradually.

The main goal of this research was to explore the use of benchmarking in the dairy industry. This includes descriptions of the various sectors in North America where benchmarking has been used successfully on a continuous basis or in research. Benchmarking methods that are currently used in the Quebec dairy industry are examined. An improvement to such methods is proposed through the use of visualization, coupled with interactivity, and with a focus on adaptability and usage. The advantages of such an interactive tool are discussed in light of on-farm decision-making, and a further use of visual slider applications is described to help with parameters of known economic importance.

Disertacijos tikslas yra ekologiškai ūkininkaujančiuosius suklasifikavus pagal jų skirtingus veiklos prioritetus, nustatyti veiksnių reikšmingumą ekologinio ūkininkavimo vystymui. Tai pasiekta išanalizavus sistemų teorijos, ekologinio ūkininkavimo, darnaus žemės ūkio vystymosi ir kaimo plėtros, aplinkosaugos, maisto kokybės bei saugos ir motyvacijos teorijos krypčių perspektyvas, identifikavus ekologinio ūkininkavimo veiksnius, atlikus empirinių tyrimų modelių ir jų pritaikomumo Lietuvos kontekstui analizę. Sukurtas ir empiriniu tyrimu patikrintas ekologinio ūkininkavimo veiksnių vertinimo teorinis modelis leido nustatyti veiksnių reikšmingumą strateginiam ūkininkų sprendimui dėl ekologės gamybos būdo plėtotės pagal dvi veiklos prioritetų požiūriu homogeniškas ekologiškai ūkininkaujančiųjų respondentų grupes (orientuotų į pelno didinimą ir į ekologinę gyvenseną). Disertacijos rezultatai suteikia naujų žinių apie ekologinį ūkininkavimą lemiančius veiksnius, leidžia sistemiškiau nei iki šiol vertinti ekologinio ūkininkavimo veiksnius. Tyrimo rezultatai gali būti pagrindas ekologinio žemės ūkio (siaurąja prasme) ir žemės ūkio darnaus vystymosi (plačiąja prasme) racionalios politikos formavimui Lietuvoje ir kitose naujosiose Europos Sąjungos šalyse, o konkretiems ūkininkams, ypač besiruošiantiems priimti strateginius sprendimus dėl ekologinio ūkininkavimo, suteikia naujų žinių. / The dissertation aim is to assess the significance of the determinants of organic farming to its development when the respondents are classified by priority of their activity. This has been achieved through the analysis of trends and perspectives of the system theory, organic farming, sustainable development of agriculture, rural development, protection of the environment, food quality and safety and the motivation theory while identifying the determinants of organic farming, and through the analysis of empiric models and their applicability in the context of Lithuania. The established and empirically tested theoretical research model for the modelling the determinants of organic farming enabled to assess the significance of the determinants to the strategic farmers’ decision whether or not to undertake the practice of organic farming according to two homogenous groups of organic respondents depending on the activity priorities (profit-oriented and organic-oriented lifestyle). The dissertation provides with new knowledge about organic farming and enables to assess the factors of organic farming more systematically than before, the research results could be a basis for the rational policy-making in the development of organic agriculture (in a narrow sense) and sustainable agriculture (in a broad sense) in Lithuania and other new countries of the European Union, and provide with new knowledge the farmers, especially those who are preparing to make the strategic decisions... [to full text]

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.

The aim of this research was to identify how farmers learn how to farm using pluriactive lifestyle block ostrich farmers who are part of the New Zealand ostrich industry as a case study. Ostrich farming is comparatively new to New Zealand farmers and the industry has attracted innovative individuals who have developed informal learning strategies. Ostrich farmers use other farmers as their main resource which is mainly facilitated through events organised by the New Zealand Ostrich Association (NZOA) and aimed at lifestyle block farmers. Ostrich farmers' community of practice is centred around their membership to the Association which enables farmers to come together to learn and socialise. For learning to effectively take place the key is social interaction, where ideas can be transferred between farmers. This thesis illustrates the important events and structure of the industry and how this has shaped farmer learning. Through semi-structured interviews and participant observation on a chick rearing farm I was able to gain a picture of how lifestyle block farmers balance full time off-farm employment while running stock, in an attempt to satisfy their version of the rural idyll. The industry is now in decline as most of the early players have exited the industry and it is now focused around New Zealand Ostrich Export (NZOE) goals. By exploring the period called the breeder phase which was characterised by some farmers making a fortune as ostrich farming was the 'next big thing' and the history since then, I have identified how these particular farmers have learned how to farm.