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This thesis complements and extends understanding of the contribution of new approaches to development to the goal of achieving sustainable rural livelihoods. This is achieved by critically evaluating the concepts of agricultural sustainability and rural livelihoods. This study examines the use and management of natural resources by smallholder farmers in central Malawi. Development interventions by PROSCARP, a development project running nationally in Malawi and funded by EU, within the case study area were evaluated. This thesis has focused on land degradation and critically evaluates the new participatory or bottom up development paradigm in light of large-scale project interventions for land husbandry. A multidisciplinary approach, utilising a range of qualitative and quantitative methods provided a sound empirical basis for assessing the complexities of rural poverty and development interventions. This thesis identified a wide range of interlinked rural problems and opportunities. This clearly indicates that a single issue, such as soil conservation, cannot be separated from other aspects of sustainable rural livelihoods. This thesis therefore argues, on the basis of empirical evidence, as well as a critical review of the literature, that agricultural sustainability must encompass all aspects of rural livelihoods. The response of farmers to development interventions is highest for technologies that directly cater to their needs or which are based on local knowledge and technologies. This thesis highlights the need to identify and target appropriate interventions for individual households. Analysis of livelihood strategies also revealed a wide diversity of income sources within the case study area. The potential for increasing agricultural production is limited by landholding size and the potential for farmers to further diversify their income or food sources should be investigated in more detail. The evidence from the literature shows that participatory development processes have achieved successes in small-scale projects. This research concludes that it is also possible incorporate and change the type of participation in a pre-existing large-scale project. The analyses in this thesis suggests that unless interactive participation or self-mobilisation is achieved there is a strong possibility that introduced technologies will not be sustained and the community may not feel the long-term benefits of the project. The main obstacle to achieving interactive participation in a large-scale project is the empowerment of the beneficiaries. Finally, in light of the results of this research a number of recommendations are discussed which include a suggested focus on individual households or marginalized groups within a community, and a clear strategy for passing control of the project to the beneficiaries to ensure long term benefits after project withdrawal.

Identifier des systèmes de productions agricoles capables de produire plus en prélevant moins de ressources et en émettant moins d’externalités négatives apparait comme une nécessité au regard du défi de nourrir 9,6 milliards d’êtres humains en 2050. Dans un programme ANR-EPAD multidisciplinaire, nous avons proposé d’explorer les outils micro-économiques d’analyse de la productivité que sont les frontières d’efficience pour apporter un nouveau regard sur le développement durable des productions animales.Empiriquement, les modèles ont montré que selon les objectifs poursuivis dans la réduction de l’éco-inefficience (réduction des inputs ou de la pollution, augmentation des outputs), les marges de progression variaient notablement. L’exploration des modèles "duaux" a démontré que les méthodes de frontières d’efficience permettent de définir les coûts implicites des externalités non-monétaires. Nos évaluations du prix d’équivalent carbone sont proches des niveaux observés des taxes carbones. Le calcul de coûts négatifs pour les excédents azotés a souligné l’intérêt des débats actuels sur l’intégration des outputs indésirable dans la méthode DEA (Data Envelopment Analysis), mais également la nature ambivalente de cet indicateur (source de pollution pour le sol ou l’air, ou de richesse en tant que fertilisant organique). Enfin, nous avons développé une approche innovante de modélisation des déterminants de l’éco-efficience. En couplant le modèle "whole-farm" GAMEDE à la méthode DEA, nous avons mis en évidence les pistes de réflexion qu’ouvre l’exploration de nouveaux types de modélisation en agronomie comme la "simulation-based optimization" ou l’ "inverse modelling". / The challenge of feeding 9.6 billion people in 2050 requires to identify sustainable livestock production systems that are able to produce more agricultural products while consuming less resources and producing less externalities. As part of a multidisciplinary research program (ANR-EPAD), we explored microeconomic tools for productivity analysis such as efficient frontiers to shed a new light on sustainable development of livestock production. Our models empirically showed that the progress margins can significantly differ depending on the objectives pursued in the context of eco-inefficiency reduction (input and pollution reduction, output augmentation). Exploration of "dual" models also showed that efficient frontier methods were relevant to provide an economic valuation of non-monetary negative externalities. For instance, our results on the economic value of carbon emissions were close to the observed carbon tax levels. The possibility for farmers to consider that nitrogen surpluses can generate some revenue illustrates the current debate on the integration of undesirable outputs in the Data Envelopment analysis (DEA), and the ambivalence of this indicator of environmental impact as well (either considered as a source of pollution to the air or soil as well as a source of income through organic fertilization). We developed an innovative approach to assess the determinants of eco-efficiency in livestock production. By combining GAMEDE (a "whole-farm" model) with a DEA methodology, we highlighted the potential for further questioning raised by the exploration of new types of modelling in agronomy (such as "simulation-based optimization" or "inverse modelling").

L’objectif de cette thèse est d’élargir au cadre multicultures la spécification des technologies de production tenant compte de la spécificité des pesticides. Cela permettra d’une part d’estimer la productivité marginale des pesticides et d’autre part de voir les conséquences de la caractérisation que l’on adopte pour modéliser les pesticides sur le niveau de cette productivité marginale. Nous partons de l’observation que les analyses empiriques essayant d’extraire la productivité marginale des pesticides se heurtent au manque de cadre théorique permettant d’analyser les exploitations agricoles multicultures. Ces études, pour contourner cette limite, soit agrègent les différents outputs pour se ramener au cas d’un seul produit, soit se limitent uniquement aux cas monocultures et/ou aux procédures d’estimation non paramétriques, procédures qui ne permettent pas l’incorporation des inputs luttant contre les ravageurs, soit passent par l’estimation d’une fonction de coût en utilisant les prix. Cette observation nous a motivé à mettre en place un cadre d’analyse adapté aux exploitations multicultures. Cela permettra de mieux comprendre le rapport des agriculteurs à cette substance. Les résultats de nos estimations montrent globalement, sur notre zone d’analyse d’Eure-et-Loir, que les exploitants agricoles utilisent de manière sous-optimale les pesticides. Ce résultat traduit d’une certaine façon l’effet de la réglementation des pesticides : les politiques publiques mises en place pour faire diminuer l’usage des pesticides ont des effets sur les décisions de production des agriculteurs d’Eure-et-Loir. / The main goal of this thesis is to enlarge to the multi-crops framework the specification of production technologies that account for the specificity of pesticides. This allows, on one side, the estimation of the marginal productivity of pesticides and on the other side to investigate the impact of the considered characterisation of pesticides on the level of their marginal productivity. We start form the observation that the current empirical analyses, trying to extract this marginal productivity of pesticides face the lack of an appropriate multi-crops framework. These studies, to get around this problem, either aggregate the different outputs to come down to the case of one crop (output), or use non parametric estimation techniques, whose drawbacks is not to handle the damage reducing input, or pass through the estimation of a cost function using the inputs price information when they are available. This observation motivates the setting up of an appropriate framework for the analysis of multi-crops farms. This enables us to well understand the intensity of farmers’ relation to this input. The results of our analysis show that the Eure-et-Loir’s farmer level of pesticide use is under-optimal. This result highlights somehow the effects of the regulation of pesticides: public policies setting up to lower the use of pesticides impact significantly the production decisions of Eure-et-Loir farmers.

This study seeks to benchmark financial efficiencies for vegetable food crop production and to demonstrate that local vegetable food crop growing is a viable option. The work identifies techniques for communities to increase sustainability on small land plots in Wales [UK]. Initial research shows limited availability of systematic data on harvest quantities and financial returns for small scale growing of vegetable food crops. When interviewed, 37 growers from an initial total of 40 were either reluctant to provide, or had failed to keep, written records of vegetable production, their costs and sales statistics. The information provided by the 37 for comprehensive personal interview questionnaires is mainly derived from memory. Organic registered growers are notionally required to keep precise production and other details by the Department for Environment Food and Rural Affairs. Analysis of the memorised data showed in most instances that outputs generated were not sufficient to support inputs. This study highlights the difficulties of collecting and collating sufficient accurate data and systematic to establish reliable benchmarks for small agricultural enterprises. Data Envelopment Analysis software initially identifies efficient and inefficient producers from the data collected but a simpler more readily understandable analysis system is now used which identifies changes in input variables needed to gauge efficiency. This study is set against a theoretical examination of global economic events that combine to discourage localisation. The overall aim is to show that in a global production framework there are hidden, deferred and obscured costs that make those processes unsustainable. Study of the produce of smallholdings and allotments in Wales allows some tentative conclusions to be drawn about appropriate benchmarks for local vegetable food crop production. This study is more important however, for the light it sheds on the current quality of data available for analysing small scale agricultural production and the general difficulties of conducting a survey to collect robust data, the analysis of which has policy implications for production, consumption and lifestyle.

Thesis (M.Sc. (Horticulture)) --University of Limpopo, 2009 / Field experiments were conducted at the University of Limpopo experimental farm, Syferkuil during 2005/06 and 2006/07 production seasons. This was initiated to examine the effect of leaf removal on cowpea biomass, protein content and grain yield under sole and binary cultures. Treatments consisted of cowpea varieties (Pan 311 and Red caloona), cropping systems (sole and intercropping) and cowpea-leaf pruning regimes (pruning and un-pruned). Sweet corn was planted, as a component crop in the intercropped plots while sole sweet corn plot was included as a treatment. All treatment combinations were laid out as Randomize complete block design (RCBD) with four replicates. Supplementary irrigation was carried out during the plant growth period. Fully expanded leaves were harvested once on all cowpea plants in the two middle rows from designated plots at seven weeks after planting for each year. Growth and yield data were collected from component crops during the course of the trial while the protein content of harvested leaves and immature pods as well as the different cowpea plant parts at harvest were determined. Results of the study revealed that leaves of cowpea variety, Pan 311 harvested prior to the reproductive stage had significantly higher protein content than those of Red caloona. Protein content of immature Pan 311 pods had higher (18.8 to 25.1%) than Red caloona (17.9 to 20.7%) during both planting seasons. The percent protein content of cowpea stem obtained at harvest for Pan 311 varied between 9.3 and 9.4%, and between 9.9 and 12.3% for Red caloona during both planting seasons. Grain yield obtained for Pan 311 and Red caloona were 1703.7 kg ha-1 and 1479.8 kg ha-1, respectively during 2005/06 and 1290.7 kg ha-1 and 511.7 kg ha-1 respectively during 2006/07 planting seasons. Sweet corn intercropped with Red caloona during both planting seasons had higher average grain yield than when intercropped with Pan 311. Although intercropping decreased the partial land equivalent ratio (LER) value of individual component crops, the combined LER values of between 1.1 and 2.3 under intercrop for the different treatment combinations implies that the practice is advantageous. The results of post harvest soil analyses revealed that topsoil has the pH value of 7.11-7.29 indicating neutral soil while subsoil pH value of 6.27-6.91 indicated slightly acidic to neutral soil during both planting seasons. Based on the findings of this study, cowpea variety Pan 311 can be recommended as a better vegetable crop than Red caloona since it has higher leaf and immature pod protein content. It also had higher grain yield than Red caloona when intercropped with sweet corn. Sweet corn had high grain yield when intercropped with Red caloona than when intercropped with Pan 311. Keywords: Cropping systems, protein content, grain yields, leaf pruning and cowpea.