http://theses.ncl.ac.uk/jspui/handle/10443/76 Tue, 03 Feb 2026 12:00:10 GMT 2026-02-03T12:00:10Z http://theses.ncl.ac.uk/jspui/handle/10443/4822 Title: Improving the agronomic management and utilisation of organic bread making wheat Authors: Wilkinson, Andrew Abstract: Yield of wheat produced under organic standards has been repeatedly shown to be 20-40% lower than achieved in conventional farming systems, with reduced protein levels. This has mainly been linked to the inability to (a) control certain diseases and (b) use foliar applications of mineral N-fertilisers late in the growing season. The organic bread making sector in the UK has therefore been unable to meet the requirements of the market without utilising imported high protein organic wheat to augment the lower protein content of the UK crop. A large scale field trial carried out between 2003 and 2005 at Gilchesters Organic Farm in Northumberland was used to investigate the effect of applying a Rhizobium inoculant and green waste compost (GWC) amendments to two-year clover swards. The trial also evaluated the effect of the agronomic management of the pre-crop fertility building on the performance and quality of subsequent wheat varieties. This consisted of three winter and four spring bread making wheat varieties, selected from a range of European wheat breeding programmes. Results identified that the addition of Rhizobium inoculant to red clover seeds improved the establishment of the clover crop, total rhizobia number per plant and rhizobia volume. The establishment of clover plants was significantly higher with inoculum (190 plants m-2) than without (152 plants m-2). The numbers of nodules per plant in the year of crop establishment were also significantly higher with inoculum than without. The nodule volume was also significantly higher with the use of inoculum than without, with a 50% increase in the size of nodules. In the second year of growth the established clover swards in the absence of inoculum had a mean plant count of 150 m-2, with a maximum predicted nodule number being achieved from 425 plants m-2. Clover swards established with the inoculant had a mean plant count of 200 m-2, with the maximum predicted nodule number achieved with 350 plants m-2. Results from the subsequent wheat variety trial showed that variety choice had a clear effect on both winter and spring wheat yields, but the improvements to fertility management practices also significantly affected yield and protein quality. For the winter wheat varieties use of Rhizobium inoculant significantly increased grain yield by 0.64 t ha-1, while use of GWC improved yield by 0.35 t ha-1 . For the spring wheats, grain yield was higher in the presence of clover inoculum (7.04 t ha-1) than in the absence (6.77 t ha-1) by 0.27 t ha-1, but the use of GWC had no effect on yield. This demonstrates clearly that yields in organic wheat production can be significantly increased by improved variety choice and fertility management regimes. Protein content for the winter wheat varieties was significantly higher in the absence of the inoculum (12.5 %) than with inoculum (11.6 %) but from grains with a smaller specific weight. The addition of GWC also significantly increased the protein content (from 11.82 % without GWC to 12.38 %). In the absence of the inoculum, grain specific weights were improved by the addition of GWC for all three winter wheat varieties. For the spring wheat varieties Rhizobium inoculum and GWC amendment had no significant effects on any of the grain quality parameters. An additional variety trial at Gilchesters Organic Farm evaluated the field performance of six spring wheat varieties from a range of European breeding programmes for their performance and grain quality in both 2006 and 2007. Results identified that variety choice had a considerable impact on yield and grain quality with large differences between seasons. The year 2006 was the best year for agronomic performance with favourable growing conditions, but yields in 2007 were significantly lower because of heavy rainfall combined with lower solar radiation levels during grain fill. Paragon and Fasan were the top yielding varieties in both years but Tybalt and Fasan produced grains of the highest grain quality. The baking performance of the varieties was in contrast to the grain quality results, i.e. Zebra, Fasan and Paragon all produced high volume loaves with high bulk fermentation after proving despite the grain analysis suggesting they were below the NABIM (National Association of British and Irish Millers) standard required for bread making. Tybalt, however, failed to hold the bulk fermentation after proving, collapsing prior to baking despite the grain quality results identifying good baking quality characteristics. Varieties Paragon and Fasan produced the best overall yield and baking results. A fertility trial was also used to evaluate the potential for additional amendments of organic manures and fertilisers, i.e. Farm Yard Manure (FYM), Green Waste Compost (GWC), Chicken Manure Pellets (CMP) and a combination of FYM + CMP applied at rates of 250 and 125 kg ha-1, on the performance of the spring wheat variety Paragon in 2006 and 2007. Results showed no significant benefits from the rate or type of fertiliser to the yield or grain quality. Although responses to fertility inputs were small in the current season of application, there are likely to be cumulative benefits later in the rotation as organic N becomes mineralised. Fertility management in an organic system is a long-term strategy based on progressively building fertility by growing N-fixing crops and supplementing this with available organic manures, as appropriate for any given organic rotation. Description: Ph. D. Thesis Tue, 01 Jan 2019 00:00:00 GMT http://theses.ncl.ac.uk/jspui/handle/10443/4822 2019-01-01T00:00:00Z http://theses.ncl.ac.uk/jspui/handle/10443/4808 Title: Evaluation of dietary habits of Singaporean post-secondary students Authors: Tay, Mia Eng Abstract: Adolescence is a period of transition in which the individual changes physically and psychologically from a child to an adult. Relative to other age groups, less is known about the diet of young Singaporeans. The aim of this work was to examine the eating habits of the mid and late adolescents, aged 17 to 21 years old, in Singapore. This age group was selected as they formed the post-secondary cohort in which, they have more autonomy in their food choices and are not bounded by school canteens. Dietary habits were compared between different genders, ethnicities, BMI classes and educational institutes. A particular focus of the study was on diet quality, breakfast intake, out-of-home eating and snacking habits. Multiple pass 24-h recalls and focus groups were used to examine the dietary habits of participants from an ITE (Institute of Technical Education), JC (Junior College) and POLY (polytechnic). A healthy eating index (HEI-SG) and three models for snacking were developed as part of the work. A total of 507 participants (100 participants each from ITE and JC, 307 from POLY) were recruited for the multiple pass 24-h recalls and six focus groups (36 participants from POLY, of which there were 18 Chinese, 9 Malays and 9 Indians) were conducted. Overall median HEI-SG scores were low at 47.2 (IQR 16) out of 100 due to an insufficient intake of total fruits, whole fruits, total vegetables, whole grains, dairy products and a high intake of sodium. More than 55% of the energy intake per day (56.58%, IQR 61.4% for female and 56.77%, IQR 52.7% for male) for both genders was contributed from food purchased out of home. It appeared that almost a third of Singaporean post-secondary students in this sample did not consume breakfast. Snacking behavior appeared frequent but estimation of this was hampered by the lack of a universally accepted definition. Three criteria and models for defining a snack were developed and tested. Divergent number of snacks/snackers were obtained, depending on the criterion used. This is the first study to use the 24-h recall method to assess the dietary intake of late adolescents living in Singapore. Public health strategies to address the low intake of fruits, vegetables, whole grains and dairy products and the high intake of sodium and frequent skipping of breakfast in this population group are recommended. Description: Ph. D. Thesis Tue, 01 Jan 2019 00:00:00 GMT http://theses.ncl.ac.uk/jspui/handle/10443/4808 2019-01-01T00:00:00Z http://theses.ncl.ac.uk/jspui/handle/10443/4440 Title: Women's empowerment in Agriculture :a case of Northeast Brazil Authors: Do Amaral Valèrio, Erika Abstract: In rural areas, strategies for promoting women’s empowerment should account for periods of drought, since droughts heighten existing gender-based inequalities and place women in an even more socially and economically vulnerable situation. Scores of efforts and resources have been targeted to promote rural women’s empowerment, but there is little to no understanding of the elements and conditions associated with this process when it comes to crises stemming from natural hazards. In this mixed-methods research project, I examine the conditions and factors associated with women’s empowerment in agriculture during periods of severe drought. In the quantitative element, I examine sexdisaggregated data from 173 households in Chapada do Apodi—a region located within the so-called “drought polygon” in the state of Rio Grande do Norte, Brazilian Northeast. Moreover, the qualitative component of this study aims to provide a better understanding of the regional context. This study’s results show that even under the circumstances of severe drought, the women from Chapada do Apodi were empowered in agriculture. The qualitative results suggest two central conditions contributed to this result: (1) the presence of the rural women’s policy agency, with its resources and connections to the women’s movement; and, (2) the technical assistance and female farmers group-related interventions that were delivered using gender awareness methodologies. Moreover, this study suggests that women’s access to credit and technical assistance are associated with empowerment in agriculture, and that membership in women-only farmer groups and access to technical assistance are related to gender parity in agriculture. These results suggest that in drought-prone areas, the institutional conditions and gender awareness methodologies tied to rural development policies could help sustain women’s empowerment in agriculture even in the face of prolonged periods of drought. Description: PhD Thesis Tue, 01 Jan 2019 00:00:00 GMT http://theses.ncl.ac.uk/jspui/handle/10443/4440 2019-01-01T00:00:00Z http://theses.ncl.ac.uk/jspui/handle/10443/4387 Title: Influence of transaction costs on market participation by smallholder poultry farmers in Nigeria : a mixed methods study Authors: Antia-Obong, Essien Akpan Abstract: Background: Market participation provides an opportunity for smallholder farmers to raise their income levels and hence improve their livelihoods. However, their decision to participate is hindered by individual, socio-economic and transaction costs (institutional) factors. Investigations into these factors have traditionally applied quantitative analysis even though transaction costs incorporate both tangible and intangible costs. Consequently, important motivations and barriers (intangible costs) perceived to influence smallholder market participation decisions have been left unobserved or unaccounted for. Setting: This study is set among smallholder poultry farmers in Nigeria. The Nigerian poultry sub-sector is under an import ban regime aimed at encouraging domestic participation in poultry markets. However, imposing a ban without a deliberate effort at instituting policies to ensure that its benefits trickle down to those mostly in need (i.e. small-scale farmers) is likely to be counter-productive. Aim: The aim of the study was to investigate the influence of transaction costs on market participation by smallholder poultry farmers in Nigeria. The objectives of the study were to first, determine the transaction costs factors influencing probability of participating in poultry markets, extent of market participation and choice of where to sell live poultry, and second, to explore perceived influences of transaction costs underlying smallholder market participation decisions. Methods: An explanatory sequential mixed methods design comprising an initial quantitative phase and a subsequent qualitative phase was employed. For the quantitative phase, primary data from a 2015 smallholder market participation survey was analysed to test for significant factors influencing smallholder market participation. For the qualitative phase, a subset of the significant factors were explored using semi-structured interviews with 20 socio-economically diverse smallholder poultry farmers recruited from participants involved in the initial quantitative survey. iii Findings: First, the quantitative analysis showed that literate female farmers with a large household and flock size, who have access to veterinary services, alternative sources of income besides poultry, and who are located further from market centres yet close to tarred roads are the type of farmers that are more likely to participate in poultry markets. Second, literate married farmers presumably female with a large flock size, who rely on the use of motorbike and mobile phone, who are native to an area and mainly rely on other farmers as the main source of market information and have lower earnings from non-farm work are the type of farmers that would intensively participate in poultry markets. Third, the market choice of poultry farmers who are remotely located with large flock sizes, who attract regular or repeat customers, who anticipate selling at a lower price per live weight of poultry whilst maintaining a strong bargaining or negotiating position would be through the farm-gate market channel. The qualitative analysis further revealed more importantly that being self-employed with a mid-level education also enhanced market participation. Conclusion: The findings from the study indicate the need for continuous rural infrastructure development in the areas of roads and telecommunications. Furthermore, in order to ease access to market information, institutionalised market information services need to be prioritised. In addition, improved access to veterinary services through technical support for farmers needs to be strengthened. In addition, land access and title deeds need to be formalised to enable long-term land use and expansion. More importantly, rural finance programmes instituted to address the credit needs of farmers should account for farmers’ educational levels and employment status to further ease market participation. The findings therefore demonstrate the importance of relying on both quantitative and qualitative evidence in smallholder market participation research. Description: PhD Thesis Mon, 01 Jan 2018 00:00:00 GMT http://theses.ncl.ac.uk/jspui/handle/10443/4387 2018-01-01T00:00:00Z