Dissertationen zum Thema „Organic farming“

Two field studies examining direct ecological weed control practices were conducted in Lexington, Kentucky. The first evaluated weed control efficacy and influence on yields of several mulches in two organically-managed bell pepper (Capsicum annum) production systems for two years. Peppers were planted in double rows in flat, bare ground or on black polyethylene-covered raised beds with drip irrigation, and four mulches (straw, compost, wood chips, and undersown white dutch clover (Trifolium repens L.) living mulch) were applied to the two production systems. In both years, polyethylene-covered raised beds produced higher yields than the flat, bare ground system. In the second year, the polyethylene-covered bed system coupled with mulching in-between beds with compost or wood chips after cultivation provided excellent weed control and yields. The second field study evaluated the efficacy of soil solarization and shallow cultivation on the invasive and noxious weed johnsongrass over two years (Sorghum halapense). A soil solarization treatment, using clear plastic stretched over soil for eight weeks, and a cultivated bare fallow treatment, utilizing a tractor pulled cultivator implement equipped with sweep blades, were randomly applied during the summers of 2003 and 2004 to a field infested with johnsongrass. Solarized and cultivated plots in both years were lightly tilled 8 months after completion of the initial treatment period. At the conclusion of the experiment the johnsongrass population was significantly reduced in all treatments and in the control plots compared to the original infestation. These two experiments testing direct weed control practices (mulching, cultivation, solarization) were undertaken in the context of an ecological weed management plan that includes long term strategies to reduce weed infestations such as crop rotation, cover cropping, and fertility management that are essential for organic farmers.

The entire thesis text is included in the research.pdf file; the official abstract appears in the short.pdf file; a non-technical public abstract appears in the public.pdf file. Title from PDF of title page (University of Missouri--Columbia, viewed January 20, 2010). Thesis advisor: Dr. Georgeanne Artz. Includes bibliographical references.

Thesis (M.S.)--West Virginia University, 2006.
Title from document title page. Document formatted into pages; contains viii, 83 p. : ill. (some col.), maps. Includes abstract. Includes bibliographical references (p. 79-83).

The aim of this work was to assay the effects of previous history of organic amendment to soils in the field on the ability of those soils to mineralise mustard, a non-legume green manure. Soil and 15N labelled mustard mineralisation was followed in laboratory microcosms. Volatilised N was assayed by direct acid trapping of N in glass fibre disks, followed by direct combustion isotope ratio mass spectrometry. Animal manures, green manures and straw added to the soil in the field in the previous season, same season and for 7 years continuously did not significantly affect these soils' ability to mineralise mustard in microcosms. Nitrification and mineralisation were the dominant processes during the first 12 days of incubation. Volatilisation rates were 1000-fold lower than mineralisation or nitrification rates. Mustard N accounted for between 1-3% of the soil mineral N, whereas only a maximum of 0.01% of mustard N was volatilised over 24 days. Soils sampled at different times in the season decomposed mustard at similar rates at stimulated low spring temperatures. Nitrification rate was reduced 5-fold more than the mineralisation rate at 8oC. Straw incorporation for seven years did not affect the subsequent recovery of 15N enriched fertiliser or of 15N from labelled straw, by oil seed rape. 15N labelled fertiliser contributed up to 63% of the winter barley N. The labelled barley straw subsequently contributed 16% of the oil seed rape N in the absence of any applied fertiliser. Ploughing in straw in the autumn, in the absence of applied fertiliser had no yield penalty or effect on crop uptake, and may retain more mineral N in the upper soil layers, lessening the risk of leaching over the winter period. The results obtained here emphasise the importance of additions of organic materials to soil in supplying plant nutrients and minimising nutrient losses.

Nitrogen (N) fixation by white clover (Trifolium repens L.) was measured in the ley phases of three experimental organic ley-arable rotations at two sites, between 1997 and 2000, using the 15N dilution technique. Soil nitrate-N, ammonium-N, and total soluble N were measured at one of the sites between 1999 and 2001. Variation of soil N was assessed in different ages of ley, year, month, rotation, site and microsite type (grass or clover). Data for soil pH, organic matter, P, K, and Mg, was also compared, as was weather data for the period. Variation of N fixation, grass and clover dry matter, proportion of nitrogen derived from the atmosphere, grass and clover N concentrations, grass and clover non symbiotic N-yield, and N transfer from clover to grass were compared in different ages of ley, years, months, rotations and sites. Flowering rates and presence of clover tap-roots were also examined. Above ground N fixation varied between 26 and 75 kg ha'1 over the course of the growing season. Estimated total N fixation ranged from 70-214 kg ha'1. N fixation was closely related to yield of clover. There were clear relationships between soil nitrate and the behaviour of the grass and clover components of the leys. Nitrate-N was slightly higher under clover patches than under grass patches in mid-late summer. White clover and perennial ryegrass were grown in circular chambers, divided radially, and their invasion into microsites with different vegetation, different management and different N treatments was observed. Ryegrass was not capable of rapidly colonising microsites by vegetative spread alone. Clover was more likely to successfully invade microsites containing grass with no added N than microsites with added N, or bare soil microsites.

Thesis (M.S.)--West Virginia University, 2005
Title from document title page. Document formatted into pages; contains vii, 51 p. : ill. (some col.). Includes abstract. Includes bibliographical references (p. 46-51).

Sweetwater Organic Community Farm is an organic farm and environmental education center located in Tampa, Florida. The farm employs the community supported agriculture (CSA) model, in which members pay a single fee before the growing season begins and receive a weekly or biweekly share of the ongoing harvest in return. Using multiple ethnographic methods, this research aimed to understand the daily operations at Sweetwater as well as the perceptions of staff and CSA members. Findings indicated that there were myriad perceived advantages of organic agriculture but also imposing challenges that needed to be overcome. Moreover, staff members acknowledged the challenges associated with the CSA model such as pleasing and educating members and, for members, having to pick up at designated times and locations. Still, staff members also noted countless benefits, including the opportunity to connect to your food, farmers, environment, and community. In surveys, CSA members indicated that they were overwhelmingly satisfied the CSA model and Sweetwater. Complexities were uncovered that are often overlooked in the literature and merit further exploration. Among these were the pressure on farmers that resulted from receiving payments upfront and the willingness of individuals to become members without understanding the CSA model. There is a need for more studies to longitudinally examine changes in social support, food system knowledge, and eating habits that may occur over the course of the growing season.

Thesis (M.S.)--West Virginia University, 2005.
Title from document title page. Document formatted into pages; contains vii, 73 p. : ill. (some col.). Includes abstract. Includes bibliographical references.

The development of environmentally-oriented farming systems and management in the agricultural sector is an objective necessity in modern terms, since the implementation of innovative technologies in agricultural activity is often accompanied by exceeding the maximum permissible limits for intensification of production of different directions. Organic agricultural production has become widely spread in the world in recent years. Ukraine also has great potential for development of this area of farming. So, starting with 2000s the organic products market capacity has been rapidly growing.

Exemplary agriculture is a grassroots alternative food movement in Shanghai, China and the surrounding countryside. At the movement’s centre are a group of 13 independent and small-scale organic farmers. This thesis outlines the movement’s formation and functioning, and discusses participants’ motivations and objectives. It also identifies relationships between movement activists and intellectuals, rural residents, volunteers on the farms and customers in the city. Exemplary agriculture is different to other alternative food movements because it is heavily influenced by the continuing legacies of state socialism. Two legacies in particular affect how exemplary agriculturalists think and act. The first is exemplarity, a form of morality and social governance that achieves order through leadership by example and the emulation of role models. Exemplarity and the promotion of role models has been a pillar of Chinese Communist Party policy since the 1940s. The second is the differentiation of the urban and the rural. The household registration system, established by the CCP in the 1950s, paved the way for the formation of powerful discourses of urban/rural difference. These discourses polarise the city and the countryside into discrete spaces and identities with clearly demarcated boundaries, privileging the urban. Exemplary agriculturalists worry about the health of Chinese society and want to provide alternatives. By growing organic produce in the countryside and selling to customers in the city, they want to relieve Chinese urbanites from anxiety caused by food safety concerns. At a deeper level, they want to influence urban attitudes toward rural China and improve relations between the two groups. Exemplary agriculturalists adopt principles derived from rural culture and call on others to emulate them. They encourage urban residents to apply these principles to their own lives, thereby facilitating alternative and better ways of city living. In short, they borrow from the rural to help the urban.

Thesis (MScAgric)--Stellenbosch University, 2002.
ENGLISH ABSTRACT:ENGLISH ABSTRACT: Organic agriculture is a growing sector world wide due to the ecological and SOCIOeconomic crisis in conventional agriculture. The International Federation of Organic Agriculture Movements (!FOAM) estimated a growth rate of between 20 and 30 percent annually across the world. This trend is also detectable in South Africa although it is still a relatively new movement. During the last two years the number of farmers who had converted to organic farming has increased sixfold and although they still account only for a minute small percentage of the total agricultural production, the increasing importance of this sector can now be observed. This was the reason for this study, which dealt specifically with the conversion process to organic farming. Based on survey results, knowledge was gathered about organic farmers in South Africa concerning sociodemographic aspects, farming operations, motivations and problems of the conversion process. In the second part of the study, the focus was placed on three farming systems in the Western Cape, including pome fruit, vegetables and table grapes. Six farms were evaluated on the basis of technical, social and economic aspects of the conversion period. Several differences were observed between organic and conventional farmers, including a higher level of education and a younger age of organic farmers. Mainly horticultural holdings were converted, with a potential for exporting. Problems farmers had to face during the conversion period included the lack of knowledge and information, higher weed infestation and high certification and inspection costs. On most of the farms it was still too early to assess the financial impacts of the conversion, but where it was possible, the feedback was mainly positive. The changes that took place during the conversion period included technical changes such as the approach to pest and disease control, fertilization and seed inputs. Essential investments at the beginning of the conversion period were a financial burden. Variable costs rose mainly as a result of an increase in labour and machinery input. The conversion period had no obvious impact on the fixed costs and thus the net farm income. With respect to these findings it was recommended to support the conversion to organic farming not only financially with different instruments such as subsidies for certification costs but also to develop an improved infrastructure for marketing, networking and information exchange. Several areas for research were identified to increase the knowledge of organic farming in the South African context.
AFRIKAANSE OPSOMMING: Organiese boerdery is wêreldwyd 'n groeiende bedryf as gevolg van die ekologiese en sosioekonomiese krisis waarin konvensionele landbou verkeer. Die International Federation of Organic Agriculture Movements (lFOAM) het die groeikoers op tussen 20 en 30 persent per jaar wêreldwyd beraam. Hierdie neiging is ook in Suid-Afrika waar te neem, alhoewel dit hier nog' n relatief nuwe beweging is. Gedurende die afgelope twee jaar het die getal boere wat na organiese boerderyomgeskakel het, sesvoudig toegeneem. Alhoewel hulle nog 'n baie klein persentasie bydra tot die totale landbouproduksie, is die toenemende belangrikheid van die bedryf waarneembaar. Dit was die beweegrede vir hierdie studie, wat spesifiek klem gelê het op die omskakelingsproses na organiese boerdey. Beskrywende inligting oor organiese boere in Suid-Afrika, soos sosio-demografiese eienskappe, boerdery-aktiwiteite, motiverings en probleme met die omskakelingsproses, is met behulp van 'n opname verkry. In die tweede gedeelte van die ondersoek is daar op drie boerderystelsels in die Wes-Kaap gefokus, naamlik vrugte, groente en tafeldruiwe. Ses boerderye is aan die hand van tegniese, sosiale en ekonomiese aspekte van die omskakelingsperiode geëvalueer. Verskeie verskille is waargeneem tussen organiese en konvensionele boere, insluitend 'n hoër vlak van opvoeding en 'n jonger ouderdom van organiese boere. Hoofsaaklik boerderye in die hortologie, met uitvoer moontlikhede is omgeskakel. Van die probleme wat boere gedurende die omskakelingsperiode ondervind het, het 'n gebrek aan kennis en inligting, hoër voorkoms van onkruid, asook hoë sertifiserings- en inspeksiekoste ingesluit. By die meeste van die boerderye was dit nog te vroeg om die finansiële impak van omskakeling te kon beoordeel, maar waar dit tog moontlik was, is hoofsaaklik 'n positiewe terugvoer gevind. Die veranderinge wat gedurende die omskakelingsperiode plaasgevind het, het tegniese veranderinge soos die benadering tot pes- en siektebeheer, bemesting en saad ingesluit. Noodsaaklike investerings aan die begin van die omskakelingsperiode het 'n finansiële las tot gevolg gehad. Koste het hoofsaaklik weens 'n toename in arbeid- en masjinerie insette gestyg. Op grond van die bevindinge van die ondersoek is aanbeveel dat ondersteuning vir die omskakeling na organiese boerdery nie net finansieel deur middel van verskillende instrumente soos subsidies vir sertifiseringskoste gegee word nie, maar om ook 'n verbeterde infrastruktuur vir bemarking, netwerke en inligtingsuitruiling te ontwikkel. Verskeie gebiede vir verdere navorsing IS geïdentifiseer om kennis oor orgamese boerdery in die Suid- Afrikaanse konteks uit te brei.

La gestione del suolo in agricoltura puo’ contribuire significativamente ad accrescere la qualita’ dei suoli. Pratiche quali le lavorazioni minime, l’applicazione di ammendanti organici e la coltivazione di colture di copertura costituiscono delle valide strategie per accrescere il contenuto di sostanza organica nei suoli agricoli e squestrare CO2 dall’atmosfera, riducendo l’impatto ambientale dell’attivita’ agricola. Il contenuto di carbonio organico (OC) nel suolo e’ controllato dall’entita’ degli input di materiale organico che giungono al suolo in seguito alla coltivazione, e dalla resistenza offerta dalla sostanza organica alla degradazione microbica. Lo studio dei meccanismi che presiedono la stabilizzazione della sostanza organica del suolo (SOM) e’ quindi di primaria importanza. La resistenza offerta dalla SOM alla degradazione microbica dipende dalle sue proprieta’ chimiche e, in maggior misura, dalle interazioni che si stabiliscono fra le molecole organiche e la matrice del suolo. Rivestono particolare importanza l’occlusione dei residui organici grossolani all’interno degli aggregati e le interazioni che si stabiliscono fra molecole organiche e superfici delle particelle minerali. La coltivazione influenza in maniera profonda questi meccanismi, determinando la quantita’ di input organici che giungono al suolo ad ogni ciclo colturale e disturbando la formazione degli aggregati tramite le lavorazioni. Lo scopo di questa ricerca e’ stato quello di analizzare come le rotazioni colturali influenzano i processi che si trovano alla base della stabilizzazione della SOM nei suoli agricoli. Lo studio ha preso in esame due rotazioni colturali svolte in un arco temporale di 13 anni. Una delle due rotazioni e’ stata caratterizzata da lavorazioni del suolo poco frequenti e dalla presenza di residui colturali ricchi in N (ALF), mentre l’altra rispondeva alle esigenze di un’agricoltura piu’ intensiva, con lavorazioni frequenti e prevalenza di colture sfruttanti (CON). I due campi sperimentali sono stati coltivati con grano duro e cece in due successive stagioni colturali e gli effetti delle rotazioni colturali effettuate nei 13 anni precedenti l’inizio dell’esperimento, cosi’ come quelli relativi alla coltivazione di grano e cece nei due campi, sono stati analizzati approfonditamente. Il primo esperimento ha preso in considerazione gli effetti delle pratiche sopra citate sulla composizione chimica della sostanza organica. Un frazionamento chimico sequenziale e’ stato applicato ai campioni di suolo, in modo da ottenere un pool di SOM labile, composto dalla frazione leggera (LF) e dal carbonio organico solubile (WSOC), e un pool recalcitrante costituito dalla frazione umica, ulteriormente divisa in acidi umici (HAs) e acidi fulvici (FAs). Il secondo esperimento ha avuto come oggetto l’analisi degli effetti delle stesse pratiche colturali sull’occlusione della sostanza organica negli aggregati e sulla formazione di complessi organo-minerali. Durante il secondo esperimento sono state isolate, mediante frazionamento per classi di aggregati e per densita’il contenuto e la composizione chimica delle particelle organiche grossolane libere (fPOM) e di quelle occluse in aggregati di diverse dimensioni, cosi’ come della frazione organica intimamente legata alle superfici dei minerali. I risultati ottenuti hanno evidenziato che la stabilizzazione della SOM e’ influenzata sia dalla intensita’ delle lavorazioni, sia dalla composizione chimica dei residui colturali, principalmente attraverso l’influenza che questi due fattori esercitano sulla formazione degli aggregati e sull’interazione fra molecole organiche e superfici dei minerali. Le lavorazioni hanno esercitato un’azione dirompente sugli aggregati, particolarmente evidente nella classe dei macro-aggregati (>200 μm). Di conseguenza, la quantita’ di macro aggregati in ALF era significativamente maggiore che in CON all’inizio dell’esperimento. Le lavorazioni svolte durante la coltivazione del grano e del cece, sebbene abbiano causato una diminuzione del contenuto di macro-aggregati in ALF, non hanno determinato una riduzione del contenuto di sostanza organica occlusa all’interno degli aggregati, probabilmente a causa della forte azione cementante svolta dal carbonato di calcio (CaCO3) sugli aggregati. I continui input di materiale organico avvenuti in ALF durante i 13 anni precedenti l’inizio dell’esperimento, hanno favorito le attivita’ della comunita’ microbica, che a sua volta ha determinato un’alta capacita’ di mineralizzare la fPOM. La composizione chimica della sostanza organica e’ cambiata significativamente nei due suoli in seguito alla coltivazione di grano e cece, come si evince dai risultati emersi in entrambi gli esperimenti. Il frazionamento chimico sequenziale ha messo in luce un aumento del contenuto di acidi umici e fulvici in entrambi i suoli in seguito alla coltivazione del cece. Il frazionamento dei suoli per classi di aggregati e per densita’ ha meso in luce un pattern piu’ complesso. In ALF l’aumento dell’intensita’ delle pratiche agricole ha determinato il rimescolamento della fPOM grossolana con parte della fPOM piu’ fine e degradata, probabilmente a causa dell’interruzione della continuita’ degli input di residui organici. Il contenuto di OC nei macro aggregati e’ diminuito, mentre e’ aumentato il ternore di OC nelle particelle non aggreagate piu’ fini. In CON la coltivazione di grano, e soprattutto del cece, ha determinato l’arrivo al suolo di residui ricchi in N. Questo ha fatto si’ che il conteuto di OC e N aumentasse nelle particelle minerali piu’ fini. L’accresciuta attivita’ microbica avvenuta in CON durante la prova di campo, e’ probabilmente alla base dell’accumulo di materiale organico relativamente “fresco” avvenuto all’interno degli aggregati. Questa ricerca ha mostrato come gli effetti delle rotazioni colturali non dipendono solamente dall’azione di disturbo alla formazione degli aggregati esercitata dalle lavorazioni del suolo, ma anche dalla qualita’ degli input organici e da processi mediati dalla comunita’ microbica, i quali influenzano l’occlusione della SOM negli aggregati e l’interazione della sostanza organica con le particell minerali.
Soil management can contribute significantly to increasing agricultural soil quality. Practices such as reduced tillage, organic amendments application and cover cropping are all recognized as valuable ways to restore the depleted SOM pools and sequester CO2 from the atmosphere, hence reducing the environmental impact of farming. The amount of organic carbon (OC) in the soil is controlled by the amount of OC returning to the soil during cultivation, and the decomposition rate, i.e. stability, of the organic input. Therefore, it is of key importance to understand the mechanisms that allow SOM to stabilize within the soil matrix. Soil organic matter (SOM) resistance to degradation depends on its chemical properties and, more importantly, on the interactions between organic molecules and the soil matrix i.e. occlusion within soil aggregates and interaction with mineral particles surfaces. Cultivation has a profound effect on of these mechanisms, as it determines the amount and chemical composition of the organic inputs that reach the soil, and includes tillage practices that disrupt soil aggregates, decreasing SOM stability. The aim of this research was to provide a scientific contribution to the understanding of how crop rotations affect the processes that underlie SOM accumulation within cropland soils. The study examined the effects of two long term (13 y) crop rotations, one characterized by low tillage intensity and N rich crop residues (ALF) and the other by higher tillage intensity and lower N input from plant residues (CON), on SOM stabilization. The effects of the introduction of a cereal-legume cropping sequence in the two fields were also observed on SOM amount and chemical composition. This experimental design allowed gaining an insight on both the long term and the short term consequences of cultivation on soil organic matter stabilization dynamics. In a first experiment, a sequential chemical fractionation was conducted on soil samples from ALF and CON in order to isolate: light fraction (LF), water soluble organic carbon (WSOC), fulvic acids (FAs) and humic acids (HAs). In a second experiment the same soil samples were subjected to a combined aggregate size and density fractionation, in order to isolate fPOM, oPOM from macro and micro-aggregates, and mineral associated organic matter in macro-aggregates, micro-aggregates and in silt and clay size particles. Our results showed that cultivation intensity and plant residues chemical composition both affected the extent to which SOM stabilizes within the soil profile, mostly via occlusion within soil aggregates and association with mineral particles. Tillage exerted a disrupting action against soil aggregates, which allowed more coarse aggregates to form in ALF, as compared to CON. Nevertheless, tillage operations conducted during the cultivation of winter wheat and chickpea, despite affecting negatively the amount of macro-aggregates in ALF, did not determine the mineralization of occluded POM, due to high level of inorganic C which acted as a cementing agent for soil aggregates. The continuous input of organic material which occurred in ALF during the 13 years before the beginning of the experiment, determined high levels of microbial activity, which determined in turn a high capacity to mineralize fPOM once the continuity of the organic input was interrupted. SOM chemical composition changed significantly in the two soils following the cultivation of winter wheat and chickpea, as it emerged from both the chemical fractionation experiment and the combined aggregate size and density fractionation experiment. In the former, we observed a consistent increase of HAs and FAs content in both the soils at 0-10 following the cultivation of chickpea. In the latter this corresponded to a complex pattern of changes occurring in the two soils across different aggregate and density fractions. In ALF, the conversion to the more intensive cropping system caused coarse fPOM to mix with finer and more degraded fPOM, as a consequence of the interruption of the continuous OC inputs. SOC content decreased in the macro-aggregates and relocated towards the silt and clay size particles, as an effect of the total macro-aggregates mass lost. The cultivation of winter wheat and chickpea in CON determined the introduction of fresh N rich plant residues. This in turn allowed for OC and N to accumulate in close association with silt and clay size particles. In addition, the cereal-legume cropping sequence caused new SOM to accumulate within soil aggregates, possibly as an effect of microbial mediated reactions. Our study showed that the effect of crop rotations on SOM accumulation and stability is not determined only by tillage disrupting action towards soil aggregates, as organic inputs quality and microbial mediated processes affect the mechanisms that allow for SOM protection via spatial inaccessibility and interaction with mineral surfaces.

As in many least developed countries the farmers in Laos are heavily dependent on subsistence based agriculture production for their livelihood. A key for increased welfare for the rural population inLaosis to increase their profits of small scale farmers and generate a higher income per capita. One possible way to increase the profits and income for smallholder farmers may be to convert in to organic rice production for the export market, since the international market for organic rice is growing, consumers are prepared to pay a premium prise for organic products and conditions for organic rice production are favourable in Laos. Organic rice farming has grown in Laos during the last decade as greater volumes of organic rice are produced and exported. Organic rice is mainly produced by smallholders in donor projects or by contract farmers supplying contract farming companies. In this thesis I try to determine the causes behind this structural transformation by incorporating evolutionary economic theory (Schumpeter, 1911; Dahmén, 1950 and Marmefelt, 1998) which focuses on entrepreneurial innovations and creditors as the basis for changes in the economy. By performing a Dahménian transformation analysis of the transition from conventional- to organic rice production within the development block around rice production in Laos, I try to determine the transformation pressure causing the transformation to take place. Emphasis is in particular given to the role of contract farming in this process. I investigate to what extent the contract farming firm can be regarded as a Schumpeterian banker, a concept introduced by Marmefelt (1998), that can coordinate the development block around rice production by providing credits to the entrepreneurs within the development block. The analysis shows that two types of transformation pressures are likely to have caused the farmers to convert to organic rice production. First of all it is likely that the relatively higher price paid for organic rice (42 percent higher than conventional rice) has convinced farmers to make the transition. This type of transformation pressure can be seen as a market pull type, as it originates from an increased demand in the international market, which in turn increases the relative price for the product. The analysis further shows that a production method innovation had taken place by the introduction of new inputs, made available by the contract farming firm. This has led to an increased productivity which, combined with the premium price, generated higher profits for the organic contract farmers. The production method innovation can be seen as a market push type of transformation pressure originating from the supply side. In this thesis I argue that it is unlikely that the transformation would have occurred without the involvement of the contract farming firm. On their own, farmers did neither have the means to grow the organic rice, nor the proper market channels to process and sell the organic rice on the international market. I argue that the contract farming firm’s ability to facilitate price signal information from the international market to farmers, provide access to the new market thru market links, and provide credits for new inputs as well as technical assistance essentially made the transition to organic rice possible. However the analysis also shows that the contract farming firm had a limited ability to fulfil its role as a coordinator in the evolvement of the organic rice production, in terms of a Schumpeterian banker, because of limited abilities to solve bottlenecks in the value chain. The reason for this is mainly limited financial resources to finance complementary investments in other parts of the development block.

This thesis explores the career of Lady Eve Balfour (1898-1990), the founder of the Soil Association, and her contribution to the British organic food and farming movement, as it emerged into public view after the Second World War. Eve Balfour's agricultural education at Reading University College during the First World War and her years as an owneroccupying farmer during the 1920s and 1930s in Suffolk are described, including her involvement in the tithe protest movement. A range of interests pursued by Eve Balfour during the inter-war period is also discussed, including novel writing and Spiritualist practices. Her 'conversion' - as war loomed - to compost-based humus famling and her corresponding rejection of inorganic fertilisers is examined, as is her decision to convert her farms into a research project to demonstrate the superiority of organic farming methods. The arguments contained in Eve Balfour's 1943 book, The Living Soil, are presented as well as evidence about advertisements and BBC radio broadcasts that drew attention to the book. The founding and primary activities of the Soil Association from 1946 through the early 1980s are outlined and the nature of the organisation considered, with emphasis placed on members' central belief in the relationship between agricultural methods and human health. The organisation's ambivalent response to science is also discussed. Eve Balfour's unconventional, New Age religious belief is explored, with questions raised about whether similar beliefs were held by other key early Soil Association figures. The impact of Eve Balfour's reputation for unconventional religious belief and the Soil Association's associated reputation for 'muck and mystery' are assessed. The tenacity of Eve Balfour in leading the organisation despite an increasingly-powerful body of support for industrial farming is emphasised, while the opportunity her New Age religious belief offered critics to dismiss the organisation she led is also acknowledged.

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 globalization and industrialization of food sector created a need for food traceability. Alternative food networks, such as organic farming, can serve this purpose by offering an alternative to the conventional food and by regaining the trust between the producer and the consumer.Organic agriculture is assumed to be more sustainable than the industrial one. However, there is a misconception of the concepts “sustainable agriculture” and “organic farming”. In Hungary the contradiction of high export of organic raw materials and high import of processed organic food from the main export countries was experienced in the 1990s. But lately the import volume decreased, and the high export remained combined with low domestic organic consumption.It is important to see how the actors involved in the organic sector perceive the sustainability of the Hungarian organic sector. The research question is: How do different actors perceive sustainability in the Hungarian organic food sector in the light of conventions theory? In order to find the answer 10 actors with different profiles were interviewed. Semi-structured qualitative interviews were carried out.Seven different conventions based on Thévenot et al. (2000) served as the analytical tool. The respondents showed low understanding of such concepts as sustainability and sustainable agriculture, as well as their contribution to sustainable development.A main conclusion of the study is that the actors closer to the field, i.e. farmers and food processing companies, show more consideration towards the environment, rural development and sustainability. Green, domestic and civic conventions are for them as important as market and industrial conventions.

Maintaining phosphorus (P) fertility in northern Great Plains (NGP) dryland organic cropping systems is a challenge due to high pH, calcareous soils that limit P bioavailability. Organic P fertilizers, including rock phosphate (RP) and bone meal (BM) are sparingly soluble in higher pH soils. Certain crops species have demonstrated an ability to mobilize sparingly soluble P sources. Objectives of this project were to 1) evaluate the effect of green manure (GM) crops and organic P fertilizers on the P nutrition of subsequent crops, and 2) investigate P fertility differences between organic and non-organic cropping systems. A two-year cropping sequence was conducted on an organic farm in north-central Montana (mean pH=6.6; Olsen P=16 mg kg⁻¹). Spring pea (Pisum sativum L), buckwheat (Fagopyrum esculentum L.), yellow mustard (Sinapis alba L.) and tilled fallow were fertilized with 0, 3.1 and 7.7 kg P ha⁻¹ as RP, grown to flat pod stage and terminated with tillage. Winter wheat (Triticum aestivum L.) was grown on these plots in year two. Phosphorus uptake of winter wheat was enhanced (P>0.05) by RP following buckwheat only (P=0.02) at 7.7 kg P ha⁻¹ compared to 0 P. Results indicate buckwheat can enhance P in a subsequent crop. A greenhouse pot experiment in a low P soil (Olsen P=4 mg kg⁻¹) consisted of four green manures; buckwheat, spring pea, wheat, and a non-crop control fertilized with 7.0 and 17.5 kg available P ha⁻¹ as RP, 13.0 and 32.5 kg available P ha⁻¹ as BM and 10 and 25 kg available P ha⁻¹ as monocalcium phosphate (MCP). Green manures were harvested, dried, analyzed for nutrient content, and returned to pots. Pots were seeded with wheat. Phosphorus uptake in wheat following all crops was enhanced by MCP (P<0.05). Phosphorus uptake of wheat following buckwheat was enhanced by all P sources over the control. Buckwheat demonstrates the capacity to increase the availability of organic P fertilizers. Soil sampling of organic and non-organic no-tillage (NT) cropping systems was conducted in two separate studies to determine differences in P availability between management systems. Soil analysis determined available P tends to be lower in non-fertilized systems.

The purpose of this research was to determine what challenges small-scale organic farmers face in choosing their particular production, marketing, and organizational strategies in Miami-Dade County. Rapid soil assessments were used on six organic farms to determine the effects of soil nutrient management in terms of pH, soil organic matter (SOM), and phosphorus (P). Potential costs of inputs were documented for each farm to determine the largest challenges facing the profitability of organic farms. A production, marketing, and organizational analysis determined how farmers shape their inter-farm competitive and cooperative relations. Preliminary findings from soil, input, labor, marketing, and organizational factors indicate that soil health varies dramatically from farm to farm, inputs and labor constitute significant costs, and marketing, production, and organizational strategies show no signs of immediate growth.

To analyse the influence of crop rotations with a different ratio of nitrogen-fixing crops, catch crops and fertilisation with organic fertilisers on the following: 1. Soil enzyme activity; 2. Agrochemical properties of the soil and nitrogen balance; 3. Weed response; 4. Weed seed bank in the soil; 5. Crop yield and productivity.
Agroekosistemų optimizavimo augalų kaita, tarpiniais pasėliais ir organinėmis trąšomis ekologinėje žemdirbystėje tyrimai vykdyti 2004–2009 m., Lietuvos žemės ūkio universiteto Bandymų stotyje, sertifikuotame ekologinės žemdirbystės lauke, karbonatingame sekliai glėjiškame išplautžemyje (IDg8-k) – Calcari-Epihypogleyic Luvisol (LVg-p-w-cc). Tyrimų hipotezė. Optimizuoti agroekosistemas ekologinėje žemdirbystėje galima taikant priemonių kompleksą: parenkant sėjomainas su skirtinga azotą fiksuojančių augalų dalimi, auginant tarpinius pasėlius bei tręšiant organinėmis trąšomis. Tyrimų tikslas – įvertinti agroekosistemų optimizavimo galimybes ekologinėje žemdirbystėje derinant sėjomainas su skirtinga azotą fiksuojančių augalų dalimi, auginant tarpinius pasėlius ir tręšiant organinėmis trąšomis. Tyrimų uždaviniai: Ištirti sėjomainų su skirtinga azotą fiksuojančių augalų dalimi, tarpinių pasėlių ir tręšimo organinėmis trąšomis įtaką: 1. dirvožemio fermentų aktyvumui; 2. dirvožemio agrocheminėms savybėms ir azoto balansui; 3. pasėlių piktžolėtumui; 4. dirvožemio armens užteršimui piktžolių sėklomis; 5. augalų derlingumui ir bendrosios energijos kiekiui. Mokslinio darbo naujumas. Ekologinės žemdirbystės sąlygomis kompleksiškai įvertintas sėjomainų su skirtinga azotą fiksuojančių augalų dalimi, tarpinių pasėlių bei tręšimo organinėmis trąšomis poveikis agroekosistemoms. Tai suteikia naujų žinių apie potencialaus dirvožemio derlingumo palaikymo, pasėlių ir dirvos piktžolėtumo kontrolės... [toliau žr. visą tekstą]

Organically managed land has increased to 4 % of the total area of agricultural land in the UK. Changing land management can impact upon the rural environment (soils, hydrology and biodiversity) and rural community (socio-economics and culture). This thesis aims to compare the effects of organic farming practices on soil physical, chemical and hydrological properties in relation to conventional farming systems. The research combines data from three different scales: field measurements, plot measurements and catchment modelling. At the field scale: 16 pairs of farms (organic and conventional between 50 and 3000 m apart) located in England, over a range of soil textures: clayey, silty, medium and coarse were investigated. There were also two different land uses (grass and winter wheat). Data was obtained on soil properties including: shear strength, Atterberg limits, field capacity, aggregate stability, HOST values, infiltration rates and Soil Organic Carbon (SOC). The analysis of the data shows that, whilst it is possible to detect the effects of both soil texture and land use (grassland / arable) on a number of the soil properties; there is no evidence that organic farming improves soil properties or physical condition - equally there is no detrimental effect. This is in agreement with the results of a number of other European studies. There was evidence to show that infiltration rates are greater on organically managed grassland than conventional grassland; which agrees with the HOST analysis where fewer fields were degraded under organic management. Fewer traces of pesticides and herbicides were in the soil water from the organic fields compared with the conventionally managed fields; none were at a level which would contribute to agricultural pollution. Cont/D.

Certified organic farming is developing rapidly world-wide and has become of interest to many farmers, politicians, environmentalists and governments and is practised now in nearly all countries of the world. However, adoption of certified organic farming is not an easy option for farmers and it carries with it several barriers such as technical, economic, social, cultural or legal. The Jordanian Government is interested in proposing organic farming to farmers, but without initially investigating whether or not organic farming will be a suitable system for farmers. Therefore, this research is based on the need to investigate the main barriers and to evaluate opportunities and potential for organic farming in Jordan’s arid lands and to propose an adoption model based on local farmer participation, using farmers’ local knowledge and their initiative, as well as institutional participation. To do so, a two-stage research methodology was employed in this research to gain the necessary data during two periods of fieldwork, April to September 2004 and July to September 2005. During this fieldwork, interviews with 46 farmers using an open questionnaire and interviews with discussion groups and government officials were conducted to investigate barriers and potential for organic farming in Jordan. Also, a national workshop was conducted attended by the Minister of Agriculture and stakeholders to evaluate and to ensure the sustainability of the proposed model. Respondents reported that the main barriers to adopting organic farming included perception, technical, nutrient availability, cultural/social, marketing, economic, institutional, lack of national regulation and lack of information and advice, but that labour was not a barrier. Findings also showed that despite barriers the area has potential for organic production owing to its extensive area, good water quality, potential farmers and international agreements. Based on the results obtained from this research, a suitable organic farming model for Jordan, and other countries having similar conditions, was developed. The model is divided into four levels: government, field, academic and regional and international, and the role of each level and its relationship with other levels is explained. The research shows that the success of this model with delivery of its objectives does not rely on the work of only the Ministry of Agriculture (MoA) or any other single body, but on everyone involved in the provision of organic farming in Jordan. Moreover, the model suggests a potential framework for an action plan on the subject of Jordan and organic farming. Also the methodology developed in this research is considered to be a great help for future researchers wanting to conduct research on organic farming or research related to sustainable agricultural development in the developing world context.

The importance of agricultural infrastructure to the development of organic farming in Libya is receiving considerable attention from policy makers in view of its potential in contributing to economic development. There is a vital role for agricultural infrastructure in promoting organic farming development in Libya. This would increase employment, enhance general economic development and stimulate growth in other sectors. Agricultural infrastructure already contributes to the general development of Libyan agriculture, and it may be vital to improving sustainability. Despite growing research interest in agriculture in Libya, there is still work to be done to bring the relationship of infrastructure and organic farming development into focus. In order to understand better the role that infrastructure plays in the development of agriculture and transformation to organic farming. This research draws on agricultural development theory to enhance understanding on the relationship between agricultural infrastructure and transformation to organic farming in Libya. Particular attention is paid to the historical development of agriculture in Libya and the role politics played in shaping agricultural development and resultant policy initiatives. The empirical focus of the research is on three main agricultural regions in Libya. This study argues that despite the fact that organic farming is in its embryonic stages in Libya, there is the potential to transform agricultural practices to facilitate organic farming if the constraints of availability and accessibility associated with current agricultural infrastructure especially at the regional and farm levels are given adequate attention with the involvement of all stakeholders including farmers. Interviews with ten agricultural experts provide a range of insights into the issues associated with infrastructure and agricultural development. A variety of issues and constraints which serve as barriers to agricultural development in Libya were identified from data collected from 277 farmers through questionnaires. The research highlights the importance of availability and accessibility of agricultural infrastructure to the transformation to organic farming in Libya. There is inadequate and inappropriate infrastructure especially at the farm level to promote the development of organicfarming practices. A variety of suggestions is presented on ways to improve the development of agriculture in Libya. This includes a suggestion for closer collaboration among all stakeholders in the agricultural sector so that the provision of agricultural infrastructure will be at the preferred areas to maximize their utilisation. This will require improved communication among all stakeholders in the planning and implementation of agricultural policies. The research highlights the importance of availability and accessibility of financial assistance to farmers as well as the provision of food processing plant. The research shows that there is potential to enhance organic farming development in Libya and has demonstrated the importance of agricultural infrastructure to this process.

To date, research on organic farming and certification has focused on the production and trade possibilities of the industry. Farmers‟ opinions are underrepresented and this study endeavours to capture their opinions. In this study, the economic problem is to investigate the low participation of farmers in certified organic farming, highlight the economic benefits which are normally not clearly defined, as well as study the often complicated and frustrating certification process. The main objective is to investigate the determinants, which affect the smallholder farmer‟s participation, and to analyse farmers‟ perceptions of certified organic farming in the Limpopo Province of South Africa. The specific focus was on the participation of smallholder farmers in certified organic farming. The dependent variable was participation as measured by a farmer‟s decision to either certify their farm or not. The independent variables included factors that make up farmer and farm characteristics, certification and market related characteristics. The study used a standard questionnaire to obtain information from farmers. The research methodology, analysis and the presentation of the study was quantitative. The study used descriptive statistics (percentages, means, standard deviations, Chi-squares and significance intervals) to evaluate the significance of the variables. These were analysed and described quantitatively by making use of EVIEWS and IBM AMOS software. In estimating the influential factors, a probit model was adopted, and in analysing farmer perception, structural equation modelling was used. v Descriptive statistics indicated that among farmers interviewed, the majority (61%) were female farmers and 39 per cent were male farmers. Among the female respondents, 46% participated in certified organic farming and 15 per cent of female farmers were not certified organic farmers. From the male group, 29 per cent were certified organic farmers and 7% were not. In determining factors influencing farmer participation, three of the variables were positively associated with the probability of participating in certified organic farming, these being: the age of the farmer, membership to a farmer organisation and market premium prices for certified commodities. The other five significant factors were negatively associated with the probability of participating in certified organic production. These factors were: the gender of the farmer, the farmers‟ income, farming experience, information access and certification costs. All these factors tended to decrease the likelihood of participating. With the exception of the farmers‟ income and farming experience, all the significant variables had the expected signs. Farmers‟ perceptions of certified organic farming were analysed and the results showed that a high percentage of farmers had a positive view of certified organic farming. In other words, the perceived benefits of certified organic farming meet farmers‟ expectations. The perceived premium price of certified organic products is the most important factor affecting farmer perception. This is not unusual because South Africa‟s organic production is mainly focused on exportation and targets high value markets. As hypothesized, the costs associated with the certification process, that is: inspection costs (-0.578) and annual certification costs (-0.719), negatively affect farmer perception. In conclusion, a combination of factors influence a farmer‟s decision as to whether or not to participate in certified organic farming. One cannot rely only on specific factors to determine farmers‟ participation in certified organic farming. Farmer perception of certified organic farming is also an important aspect. The more farmers positively perceive the farming enterprise, the higher the rate of participation will be. The same applies to the perceived costs, which have a negative impact on participation. The study finally recommends that government complete and put into practice the South African organic regulations, which may motivate farmers to get involved in certified organic farming and encourage local capacity building in certified organic farming. However, in the meantime, government should place an vi emphasis on self-regulation within farmer groups and cooperatives for organic production, and set up a regulator to monitor the current activities. This would enhance interest from potential farmers, and strengthen consumer confidence. The study further recommends that information on organic farming should be improved by encouraging more research in this area, which will enable farmers, consumers and regulators to access data on socio-economic, production and trade in the industry. Government should support or create a partnership between farmers and processors to establish cost effective processing of organic products and to increase the availability of processed products for market. Government should assist non-certified smallholder organic farmers to become certified, potentially resulting in a price premium for their products and enhancing export capabilities.
Dissertation (MSc Agric)--University of Pretoria, 2013.
gm2014
Agricultural Economics, Extension and Rural Development
unrestricted

Thesis (M.S. in soil science)--Washington State University, August 2009.
Title from PDF title page (viewed on Sept. 23, 2009). "Department of Crop and Soil Science." Includes bibliographical references (p. 46-50).

Field trials were conducted in 2010/11, 2012 and 2013 at the Royal Agricultural University’s Soil Association certified organic Harnhill Manor Farm, Gloucestershire, UK (NGR SP 075 006), to investigate suitable cultivation techniques and legume cover crops for winter and spring wheat production. Cultivation treatments included conventional tillage (CT), low residue non-inversion tillage (LRNiT) and high residue non-inversion tillage (HRNiT) as main plots while undersowing white clover (WC), black medic (BM) or no undersowing (Nus) as subplots. Wheat establishment, growth, grain yield and weeds infestation were assessed to determine the feasibility of these husbandry techniques. For winter wheat in 2010/11, LRNiT seems to be an acceptable alternative for CT. However, for spring wheat in 2012 and 2013, CT seems to be more reliable management option. The performance of undersown legumes was highly weather reliant and inconsistent in the seasons studied. Plant establishment and the succeeding yield parameters were positively related to grain yield. CT had significantly higher plant establishment than LRNiT or HRNiT in each season. For winter wheat, the competition and compensation on shoot density among CT and LRNiT did potentially outweighed cultivation-induced effects on plant establishment. This condition resulted in statistically equivalent crop growth and yields with LRNiT to that of CT. In contrast, for spring wheat in 2012 and 2013, CT that had significantly higher plant establishment also resulted in better crop growth and greater grain yields than other cultivation treatments. In all seasons, HRNiT had significantly lower plant establishment and also reduced grain yields, compared with LRNiT or CT. More soil cultivation also significantly reduced total weeds than less tilled soil such as HRNiT. On the basis of weed species, significantly higher broadleaf weeds were present under CT and significantly higher grass weeds were present under HRNiT. Out of three investigated years, legume cover crops effects were clearly observed only in 2012 with spring wheat. More vigorous growth of WC showed a significantly inverse relationship with broadleaf weeds and total weeds, compared with slow growing BM. This situation, resulted in non-significant yield components or grain yield reduction, compared with non-undersown spring wheat. In this context, white clover seems to be more suitable legume cover crop than black medic.