Dissertationen: „Crops and climate“

1

Kambanje, Ardinesh. „Productivity and profitability of different maize varieties and cropping systems used in the smallholder sector of the Eastern Cape Province of South Africa : implication on food security“. Thesis, University of Fort Hare, 2018. http://hdl.handle.net/10353/6237.

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Low maize yields in the midst of abundant arable land, favourable climatic conditions, input and financial support programs, plagues smallholder maize farming in Eastern Cape Province. These scenarios have led the province to be a net importer of maize. In essence, low production may signify a mis-match between maize varieties being promoted amongst smallholder farmers and their farming system. Thus, the main objective of the study was to investigate the productivity and profitability of different maize varieties and cropping system under smallholder agriculture in selected villages of the Eastern Cape Province of South Africa as well as, the implications posed on the household food security. The study sought to assess: (i) the productivity of different maize varieties and cropping systems, (ii) the effect of GM maize adoption on food security among smallholder farmers, (iii) the profitability of GM, conventional hybrids and OPV maize varieties produced by farmers under different agro-ecological conditions and (iv) the impact of different maize varieties and cropping systems on food security in the smallholder agriculture. A cross sectional quantitative-based survey study was carried out to obtain information from a total of 650 small holder farmers. The study was conducted in three local municipalities in Oliver Reginald (OR) Tambo District Municipality of the Eastern Cape Province of South Africa. Descriptive statistics, partial factor productivity, gross margin analysis, household food insecurity access score (HFIAS), ordinal logistic and linear regression were the analytical techniques used in establishing correlations among variables. Results obtained from the survey indicated that under mono-cropping system, Genetically Modified (GM) maize variety was highly productive with an average yield of 1.9 t/ha whilst, improved OPV maize variety was productive (with an average yield of 1.6 t/ha) under mixed cropping system. Furthermore, GM maize (GM = -R418.10), and landrace (GM = -R1 140.29) maize varieties had negative gross margins whilst, conventional hybrids (GM = R5 181.21) and improved OPV (GM = R1 457.41) were profitable. There was a significant and negative correlation between use of GM maize variety and reduction of household food insecurity. GM maize varieties, improved OPV, white maize, white as well as yellow GM maize varieties had a significant impact in reducing household food insecurity; whilst using more than one variety of maize (landraces and GMO) positively influenced household food insecurity. In light of these research findings, it is recommended that, there is need to address household food security by growing improved OPVs under a mixed cropping system and GM maize under monocropping system.

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2

Schmidt, Holger. „Neue stabile Germylene Ligandeneffekte, Struktur, Reaktivität /“. [S.l. : s.n.], 1998. http://catalog.hathitrust.org/api/volumes/oclc/76007677.html.

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3

Ng, Wai-yip. „Impact of climatic change during little ice age on agricultural development in north China, 1600-1650 Xiao bing qi qi hou bian qian yu Hua bei nong ye fa zhan : 1600-1650 nian jian de guan cha /“. Click to view the E-thesis via HKUTO, 2009. http://sunzi.lib.hku.hk/hkuto/record/B43209397.

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4

Wang, Xuhui. „Impacts of climate change and agricultural managements on major global cereal crops“. Electronic Thesis or Diss., Paris 6, 2017. https://accesdistant.sorbonne-universite.fr/login?url=https://theses-intra.sorbonne-universite.fr/2017PA066625.pdf.

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Les terres cultivées représentent un cinquième de la surface émergée de la Terre. Elles fournissent des nutriments à l'homme, modifient le cycle biogéochimique et l'équilibre énergétique de la terre. L’évolution des terres cultivées dans le contexte du changement climatique et avec une intensification des actions anthropiques constitue un enjeu important pour la sécurité alimentaire et les exigences environnementales du développement durable. Le manuscrit de thèse s’inscrit dans cette thématique en exploitant les données de différentes sources et la modélisation numérique. Les données utilisées sont : les statistiques de rendements, les observations agro-météorologiques à long terme, les résultats des sites d’expérimentation avec du réchauffement, les jeux de données globales issus des processus de fusion ou d’assimilation, les données climatiques historiques et de projection future. La modélisation fait appel aux modèles statistiques et aux modèles de processus. Le manuscrit est composé d’une série de travaux de détection et d'attribution. Ils explorent la phénologie, le rendement et leurs réponses aux changements climatiques et aux pratiques de gestion. Ils sont soit sur l'échelle régionale soit sur l’échelle globale, en fonction de la disponibilité des données et de leur pertinence. Le chapitre 2 décrit la construction et l’utilisation d'un modèle statistique avec des données provinciales de rendement au Nord-est de Chine et des données climatiques historiques. Les résultats montrent un effet asymétrique de la température diurne sur le rendement du maïs. Le rendement du maïs augmente de 10.0±7.7% en réponse à une augmentation moyenne de 1oC pendant la saison de croissance quand il s’agit de la température minimale de nuit (Tmin), mais le rendement diminue de 13,4±7,1% quand il s’agit de la température maximale de jour (Tmax). Il y a une grande disparité spatiale pour la réponse à Tmax, ce qui peut s'expliquer partiellement par le fort gradient spatial de la température pendant la saison de croissance (R = -0,67, P <0,01). La réponse du rendement aux précipitations dépend aussi des conditions d'humidité. Malgré la détection d'impacts significatifs du changement climatique sur le rendement, une part importante de ses variations n’est pas expliquée par les variables climatiques, ce qui souligne le besoin urgent de pouvoir attribuer proprement les variations de rendement au changement climatique et aux pratiques de gestion. Le chapitre 3 présente le développement d’un algorithme d'optimisation basé sur la théorie de Bayes pour optimiser les paramètres importants contrôlant la phénologie dans le modèle ORCHIDEE-crop. L’utilisation du modèle optimisé permet de distinguer les effets de la gestion de ceux du changement climatique sur la période de croissance du riz (LGP). Les résultats du modèle optimisé ORCHIDEE-crop suggèrent que le changement climatique affecte la LGP différemment en fonction des types du riz. Le facteur climatique a fait raccourcir la LGP du riz précoce (-2,0±5,0 jour / décennie), allonger la LGP du riz tardif (1,1±5,4 jour / décennie). Il a peu d'effet sur la LGP du riz unique (-0,4±5,4 jour / décennie). Les résultats du modèle ORCHIDEE-crop montrent aussi que les changements intervenus dans la date de transplantation ont provoqué un changement généralisé de la LGP, mais seulement pour les sites de riz précoce. Ceci compense à la hauteur de 65% le raccourcissement de la LGP provoquée par le changement climatique. Le facteur dominant du changement LGP varie suivant les trois types de riz. La gestion est le principal facteur pour les riz précoce et unique. Ce chapitre démontre aussi qu'un modèle optimisé peut avoir une excellente capacité à représenter des variations régionales complexes de LGP
Croplands accounts for one-fifth of global land surface, providing calories for human beings and altering the global biogeochemical cycle and land surface energy balance. The response of croplands to climate change and intensifying human managements is of critical importance to food security and sustainability of the environment. The present manuscript of thesis utilizes various types of data sources (yield statistics, long-term agrometeorological observations, field warming experiments, data-driven global datasets, gridded historical climate dataset and projected climate change) and also modelling approaches (statistical model vs. process model). It presents a series of detection and attribution studies exploring how crop phenology and crop yield respond to climate change and some management practices at regional and global scales, according to data availability. In Chapter 2, a statistical model is constructed with prefecture-level yield statistics and historical climate observations over Northeast China. There are asymmetrical impacts of daytime and nighttime temperatures on maize yield. Maize yield increased by 10.0±7.7% in response to a 1 oC increase of daily minimum temperature (Tmin) averaged in the growing season, but decreased by 13.4±7.1% in response to a 1 oC warming of daily maximum temperature (Tmax). There is a large spatial variation in the yield response to Tmax, which can be partly explained by the spatial gradient of growing season mean temperature (R=-0.67, P<0.01). The response of yield to precipitation is also dependent on moisture conditions. In spite of detection of significant impacts of climate change on yield variations, a large portion of the variations is not explained by climatic variables, highlighting the urgent research need to clearly attribute crop yield variations to change in climate and management practices. Chapter 3 presents the development of a Bayes-based optimization algorithm that is used to optimize key parameters controlling phenological development in ORCHIDEE-crop model for discriminating effects of managements from those of climate change on rice growth duration (LGP). The results from the optimized ORCHIDEE-crop model suggest that climate change has an effect on LGP trends, but with dependency on rice types. Climate trends have shortened LGP of early rice (-2.0±5.0 day/decade), lengthened LGP of late rice (1.1±5.4 day/decade) and have little impacts on LGP of single rice (-0.4±5.4 day/decade). ORCHIDEE-crop simulations further show that change in transplanting date caused widespread LGP change only for early rice sites, offsetting 65% of climate-change-induced LGP shortening. The primary drivers of LGP change are thus different among the three types of rice. Management is predominant driver of LGP change for early and single rice. This chapter demonstrated the capability of the optimized crop model to represent complex regional variations of LGP. Future studies should better document observational errors and management practices in order to reduce large uncertainties that exist in attribution of LGP change and to facilitate further data-model integration. In Chapter 4, a harmonized data set of field warming experiments at 48 sites across the globe for the four most-widely-grown crops (wheat, maize, rice and soybean) is combined with an ensemble of gridded global crop models to produce emergent constrained estimates of the responses of crop yield to changes in temperature (ST). The new constraining framework integrates evidences from field warming experiments and global crop modeling shows with >95% probability that warmer temperatures would reduce yields for maize (-7.1±2.8% K-1), rice (-5.6±2.0% K-1) and soybean (-10.6±5.8% K-1). For wheat, ST was less negative and only 89% likely to be negative (-2.9±2.3% K-1). The field-observation based constraints from the results of the warming experiments reduced uncertainties associated with modeled ST by 12-54% for the four crops

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5

Champalle, Clara. „Cash crops and climate shocks: flexible livelihoods in Southeast Yunnan, China“. Thesis, McGill University, 2013. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=114509.

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The rural landscape of the People's Republic of China has changed dramatically from land collectivization in the 1950s to the decollectivization reforms initiated by Deng Xiaoping in 1979. By the mid-1980s each rural household had again become responsible for its own agricultural production, and food security began to improve, even within the most remote areas. To further this agrarian transition, in the late 1990s the central state devised the Western Development Strategy to advance its 'less developed' western regions, within which provincial governments subsidized cash crops. The aim of this thesis is first to examine the importance of cash crops and related subsidies for Han and minority nationality farmer households in Honghe Hani-Yi Autonomous Prefecture, Yunnan, China; second, to assess how extreme weather events affect these farmers' livelihoods and to investigate the coping mechanisms they employ. To answer this aim I draw on a conceptual framework that incorporates key elements from sustainable livelihoods, food security, and vulnerability and resilience to climate variability literatures. Focusing on four townships in Honghe Prefecture, southeast Yunnan, I completed statistical analyses of quantitative data regarding recent extreme weather events in the region and ethnographic fieldwork, including conversational interviews with farmers and semi-structured interviews with local officials completed in summer 2011. I find that state-sponsored cash crops do not always bring higher financial capital rewards and that cash crop farmers have been increasingly exposed to extreme precipitation and temperatures since the year 2000, which constrain their access to livelihood capitals, essential for (re)investing in cash cropping. In turn, farmers cope with and/or adapt to climate shocks according to their initial livelihood decision-making and the specifics of the event, while also being influenced by their location and ethnicity. In sum, I argue that farmers' vulnerability is rooted in social, temporal and spatial variables, many of which are not being considered by state officials.
Le paysage rural de la République Populaire de Chine s'est considérablement transformé depuis la collectivisation dans les années 50 jusqu'aux réformes de dé-collectivisation instauré par Deng Xiaoping en 1979. Au milieu des années 80, chaque ménage rural est redevenu responsable de sa propre production agricole et la sécurité alimentaire semble s'être améliorée, même dans les régions les plus reculées. Pour intensifier la transition agraire et le développement rural, l'état a commencé à la fin des années 90 à subventionner les cultures commerciales au niveau provincial, à travers sa « Stratégie de développement de l'ouest du pays ». L'objectif de ce mémoire est premièrement d'examiner l'importance des cultures commerciales subventionnées par l'état pour les agriculteurs, particulièrement issus des minorités ethniques (Yi, Hmong, Yao, et Zhuang) et de la majorité Han dans la Préfecture de Honghe, Yunnan; et deuxièmement d'évaluer les effets des phénomènes climatiques extrêmes sur leurs moyens d'existence et d'étudier les mécanismes de survie auxquels ils ont recours. Pour remplir cet objectif, j'utilise un cadre théorique incorporant les éléments clés des littératures sur les moyens d'existence durables, la sécurité alimentaire, ainsi que la vulnérabilité et la résilience à la variabilité du climat. Mes méthodes comprennent une analyse statistique des données quantitatives des récents phénomènes climatiques extrêmes dans la région et un travail ethnographique dans quatre cantons de la Préfecture de Honghe, notamment des entrevues non structurées avec les agriculteurs et semi-structurées avec les cadres locaux au cours de l'été 2011. Je constate que les cultures commerciales subventionnées par l'état ne s'accompagnent pas toujours d'une amélioration du capital financier des agriculteurs et que ces cultures sont de plus en plus exposées à de fortes précipitations et d'extrêmes températures, qui réduisent l'accès aux capitaux de subsistance, nécessaire au réinvestissement dans les cultures commerciales. Par conséquent, les agriculteurs développent des stratégies de survie et/ou d'adaptation selon leurs moyens d'existence choisis et le type de phénomènes climatiques, mais sont également affectés par leur emplacement et leur ethnicité. En somme, je remarque que l'accès des agriculteurs aux ressources est essentiellement fonction de trois variables : sociale, temporelle et spatiale ; celles-ci souvent ignorées par les cadres gouvernementaux.

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6

Wang, Xuhui. „Impacts of climate change and agricultural managements on major global cereal crops“. Thesis, Paris 6, 2017. http://www.theses.fr/2017PA066625/document.

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Les terres cultivées représentent un cinquième de la surface émergée de la Terre. Elles fournissent des nutriments à l'homme, modifient le cycle biogéochimique et l'équilibre énergétique de la terre. L’évolution des terres cultivées dans le contexte du changement climatique et avec une intensification des actions anthropiques constitue un enjeu important pour la sécurité alimentaire et les exigences environnementales du développement durable. Le manuscrit de thèse s’inscrit dans cette thématique en exploitant les données de différentes sources et la modélisation numérique. Les données utilisées sont : les statistiques de rendements, les observations agro-météorologiques à long terme, les résultats des sites d’expérimentation avec du réchauffement, les jeux de données globales issus des processus de fusion ou d’assimilation, les données climatiques historiques et de projection future. La modélisation fait appel aux modèles statistiques et aux modèles de processus. Le manuscrit est composé d’une série de travaux de détection et d'attribution. Ils explorent la phénologie, le rendement et leurs réponses aux changements climatiques et aux pratiques de gestion. Ils sont soit sur l'échelle régionale soit sur l’échelle globale, en fonction de la disponibilité des données et de leur pertinence. Le chapitre 2 décrit la construction et l’utilisation d'un modèle statistique avec des données provinciales de rendement au Nord-est de Chine et des données climatiques historiques. Les résultats montrent un effet asymétrique de la température diurne sur le rendement du maïs. Le rendement du maïs augmente de 10.0±7.7% en réponse à une augmentation moyenne de 1oC pendant la saison de croissance quand il s’agit de la température minimale de nuit (Tmin), mais le rendement diminue de 13,4±7,1% quand il s’agit de la température maximale de jour (Tmax). Il y a une grande disparité spatiale pour la réponse à Tmax, ce qui peut s'expliquer partiellement par le fort gradient spatial de la température pendant la saison de croissance (R = -0,67, P <0,01). La réponse du rendement aux précipitations dépend aussi des conditions d'humidité. Malgré la détection d'impacts significatifs du changement climatique sur le rendement, une part importante de ses variations n’est pas expliquée par les variables climatiques, ce qui souligne le besoin urgent de pouvoir attribuer proprement les variations de rendement au changement climatique et aux pratiques de gestion. Le chapitre 3 présente le développement d’un algorithme d'optimisation basé sur la théorie de Bayes pour optimiser les paramètres importants contrôlant la phénologie dans le modèle ORCHIDEE-crop. L’utilisation du modèle optimisé permet de distinguer les effets de la gestion de ceux du changement climatique sur la période de croissance du riz (LGP). Les résultats du modèle optimisé ORCHIDEE-crop suggèrent que le changement climatique affecte la LGP différemment en fonction des types du riz. Le facteur climatique a fait raccourcir la LGP du riz précoce (-2,0±5,0 jour / décennie), allonger la LGP du riz tardif (1,1±5,4 jour / décennie). Il a peu d'effet sur la LGP du riz unique (-0,4±5,4 jour / décennie). Les résultats du modèle ORCHIDEE-crop montrent aussi que les changements intervenus dans la date de transplantation ont provoqué un changement généralisé de la LGP, mais seulement pour les sites de riz précoce. Ceci compense à la hauteur de 65% le raccourcissement de la LGP provoquée par le changement climatique. Le facteur dominant du changement LGP varie suivant les trois types de riz. La gestion est le principal facteur pour les riz précoce et unique. Ce chapitre démontre aussi qu'un modèle optimisé peut avoir une excellente capacité à représenter des variations régionales complexes de LGP
Croplands accounts for one-fifth of global land surface, providing calories for human beings and altering the global biogeochemical cycle and land surface energy balance. The response of croplands to climate change and intensifying human managements is of critical importance to food security and sustainability of the environment. The present manuscript of thesis utilizes various types of data sources (yield statistics, long-term agrometeorological observations, field warming experiments, data-driven global datasets, gridded historical climate dataset and projected climate change) and also modelling approaches (statistical model vs. process model). It presents a series of detection and attribution studies exploring how crop phenology and crop yield respond to climate change and some management practices at regional and global scales, according to data availability. In Chapter 2, a statistical model is constructed with prefecture-level yield statistics and historical climate observations over Northeast China. There are asymmetrical impacts of daytime and nighttime temperatures on maize yield. Maize yield increased by 10.0±7.7% in response to a 1 oC increase of daily minimum temperature (Tmin) averaged in the growing season, but decreased by 13.4±7.1% in response to a 1 oC warming of daily maximum temperature (Tmax). There is a large spatial variation in the yield response to Tmax, which can be partly explained by the spatial gradient of growing season mean temperature (R=-0.67, P<0.01). The response of yield to precipitation is also dependent on moisture conditions. In spite of detection of significant impacts of climate change on yield variations, a large portion of the variations is not explained by climatic variables, highlighting the urgent research need to clearly attribute crop yield variations to change in climate and management practices. Chapter 3 presents the development of a Bayes-based optimization algorithm that is used to optimize key parameters controlling phenological development in ORCHIDEE-crop model for discriminating effects of managements from those of climate change on rice growth duration (LGP). The results from the optimized ORCHIDEE-crop model suggest that climate change has an effect on LGP trends, but with dependency on rice types. Climate trends have shortened LGP of early rice (-2.0±5.0 day/decade), lengthened LGP of late rice (1.1±5.4 day/decade) and have little impacts on LGP of single rice (-0.4±5.4 day/decade). ORCHIDEE-crop simulations further show that change in transplanting date caused widespread LGP change only for early rice sites, offsetting 65% of climate-change-induced LGP shortening. The primary drivers of LGP change are thus different among the three types of rice. Management is predominant driver of LGP change for early and single rice. This chapter demonstrated the capability of the optimized crop model to represent complex regional variations of LGP. Future studies should better document observational errors and management practices in order to reduce large uncertainties that exist in attribution of LGP change and to facilitate further data-model integration. In Chapter 4, a harmonized data set of field warming experiments at 48 sites across the globe for the four most-widely-grown crops (wheat, maize, rice and soybean) is combined with an ensemble of gridded global crop models to produce emergent constrained estimates of the responses of crop yield to changes in temperature (ST). The new constraining framework integrates evidences from field warming experiments and global crop modeling shows with >95% probability that warmer temperatures would reduce yields for maize (-7.1±2.8% K-1), rice (-5.6±2.0% K-1) and soybean (-10.6±5.8% K-1). For wheat, ST was less negative and only 89% likely to be negative (-2.9±2.3% K-1). The field-observation based constraints from the results of the warming experiments reduced uncertainties associated with modeled ST by 12-54% for the four crops

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7

Ozdes, Mehmet. „The effect of climate and aerosol on crop production: a case study of central Asia“. Thesis, Georgia Institute of Technology, 2012. http://hdl.handle.net/1853/48997.

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The effect of recent climate change in Central Asia poses a significant and potentially serious challenge to the region’s agricultural sector. An investigation of the aerosol-climate- crop yield correlation in this region is essential for a better understanding of the effect of aerosols and climate on Central Asian agriculture. Our goal is to investigate the linkages between aerosol, climate and major crop production (cotton, maize, wheat, and rice) in specified agricultural regions in the five Central Asian countries. Our approach is to perform the Pearson’s Correlation Coefficient analysis in order to observe the statistical correlation between crop yield, temperature, precipitation, and aerosol optical depth (AOD), for each indicated agricultural region in the selected countries. Besides, using NASA GIOVANNI website tools, we retrieve distribution maps and time series of temperature, precipitation and AOD to facilitate the analyses. The research shows that in some aspects, the relation between AOD, climate, and crop yield is different in Central Asia than in previous global or large scale research hypotheses. The statistical correlations vary not only across countries but also across agricultural regions. For example, in Kazakhstan, opposite correlations exist between precipitation and AOD in two different agricultural regions even though both regions are rain-fed. In the more arid countries (with lower rain rates) such as Turkmenistan and Uzbekistan, no correlation exists between crop production and temperature, precipitation, and AOD, while the less arid (with higher rain rate) countries (Kazakhstan, Kyrgyzstan, and Tajikistan) indicate a positive correlation.

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Ng, Wai-yip, und 吳偉業. „Impact of climatic change during little ice age on agricultural development in north China, 1600-1650“. Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2009. http://hub.hku.hk/bib/B43209397.

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Almaraz, Suarez Juan Jose. „Climate change and crop production in southwestern Quebec : mitigation and adaptation“. Thesis, McGill University, 2007. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=103364.

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Anthropogenic greenhouse gas emissions are the main cause of increasing global temperatures. Climate change will affect crop production in Canada and, in turn agriculture has the potential to mitigate climate change. Analysis of historical climate and corn yield data, and field and greenhouse experiments were carried out in order to study the effect of climate variability and changes on corn yield, the adaptability of cropping systems to climate change conditions, the effect of tillage on soil greenhouse gas emissions (CO2 and N2O) associated with corn and soybean production, and the potential of Nod factors to increase biomass as way to mitigate CO2 emissions. In southwestern Quebec, corn yield variability has been strongly associated to July temperature and May precipitation during the last three decades. Field studies showed that switchgrass and sorghum-sudangrass were best adapted to dry and warm climate events. No-till improved corn yield when spring temperatures were warmer than normal. Soil CO2 fluxes were associated with temperature, while soil N2O fluxes were associated with precipitation. Conventional tillage (CT) had greater CO2 emissions than no-till (NT), particularly after disking in the spring. Both tillage systems had large N2O emission peaks during the wettest part of the season. In corn, peaks of N 2O occurred after nitrogen fertilizer application. NT had greater N 2O emissions than CT in the corn production systems; however, CT had greater N2O fluxes than NT in the soybean production system. Nod factors sprayed on soybean increased photosynthesis and biomass under controlled conditions. In the field, yield was increased by Nod factors under CT, but not under NT, and drought reduced the soybean response to Nod factors.
Les émissions anthropogènes de gaz à effet de serre sont la cause principale de l'augmentation globale des températures. Les changements climatiques vont affecter la production agricole au Canada, et en retour, l'agriculture pourrait limiter les changements climatiques. L'analyse de données historiques du climat et des rendements de maïs, combinés avec des expériences de serre et en champ ont été entreprises pour étudier l'effet de la variabilité et des changements de climat sur le rendement de maïs, l'adaptabilité des systèmes agricoles aux changements climatiques, l'effet du travail du sol sur les émissions de gaz à effet de serre (C02 et N20) associées avec la production de maïs et de soya, et le potentiel des facteurs Nod d'augmenter la biomasse pour limiter les émissions de CO2. L'analyse des données historiques ont démontré qu'au sud-ouest du Québec, la variabilité des rendements de maïs est fortement associée avec les températures de juillet et les précipitations de mai pendant les dernières trois décennies. Les expériences au champ ont démontré que le panic raide, et le sorghum-sudangrass sont les mieux adaptés aux conditions chaudes et sèches. Le semis direct a augmenté les rendements de maïs lorsque les températures printanières étaient plus chaudes que la normale. Les flux de C02 étaient associés avec la température, mais les flux de N20 étaient associés avec les précipitations. Le travail du sol conventionnel (CT) a produit plus d'émissions de CO2 que le semis direct (NT), particulièrement après le disquage au printemps. Les deuxsystèmes ont montré un large pic d'émission de N20 pendant les périodes les pluspluvieuses. Dans le maïs, les pics de N20 ont été détectés après la fertilisation enazote. NT a montré des émissions de N20 plus importantes que CT en productionde maïs, mais CT a montré des flux de N20 plus important que NT en productionde soya. Les facteurs Nod vaporisés sur le soya ont augmenté la photosynthèse etla biomasse sous conditions controllées. Au champ, le rendement a été augmentépar les facteurs Nod sous CT, mais pas sous NT, et la sécheresse a réduit laréponse du soya aux facteurs Nod.

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10

Sundelin, William. „Growing crops or growing conflicts? : Climate variability, rice production and political violence in Vietnam“. Thesis, Försvarshögskolan, 2021. http://urn.kb.se/resolve?urn=urn:nbn:se:fhs:diva-9757.

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This thesis contributes to research on climate change and violent conflict by testing the theory of a causal relationship between climate variability, agricultural production and political violence in the case of Vietnam 2010-2019. Climate-related negative shocks to agricultural production in developing countries are expected to lower the opportunity cost of violence through an income effect. This increases the risk of violent conflict. The thesis draws on a framework that combines climate-conflict research, civil war theory and research on how climactic factors affect rice cultivation in Southeast Asia. It tests the hypotheses emerging from the framework using mixed-effect models and a counterfactual comparison. Minimum temperature increases in the growing season for rice have been found to decrease rice yields, while maximum temperature increases have a positive effect on yield.The results show that minimum temperature increases are averse to Vietnamese rice production and have a positive relationship with political violence in the following year. Maximum temperature however is not significantly related to either rice production or violence. These results are in line with the hypotheses drawn from the framework. The minimum temperature effect on political violence is small compared to some of the covariates but robust to several different model specifications. The results provide evidence of a climate-conflict link through agricultural production in contemporary Vietnam which is similar to the findings in existing case studies in Southeast Asia. However, more research will be needed to decisively identify the causal mechanism and the specifics of how it works.

The seminar was held digitally.

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Hayman, Peter Theodore, of Western Sydney Hawkesbury University, of Science Technology and Environment College und School of Environment and Agriculture. „Dancing in the rain : farmers and agricultural scientists in a variable climate“. THESIS_CSTE_EAG_Hayman_P.xml, 2001. http://handle.uws.edu.au:8081/1959.7/138.

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This study describes how farmers manage climate variability in dryland crop production, and aims to contribute to the theory and practice of decision support for managing climate variability. The intent was to study farmer decision making to see how DSS could be used to deliver information and procedures on climate risk to farmers more effectively. The study investigated whether there are significant differences between farmers' subjective distributions of seasonal rainfall and its derivatives (such as crop yield and fallow recharge) and a probability distribution derived from long-term records and simulation models, and whether these differences in risk assessment lead to changes in the optimum decision. Subjective probability distributions of rainfall and its derivatives were collected from farmers and advisers and it was found the overall match between these and long term records and simulation models was close. This study found little evidence to support the role of DSS for routine decision making, but this does not lessen the value of distributions derived from simulation models. Rather, it provides an opportunity for both farmers and scientists to learn.
Doctor of Philosophy (PhD)

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Matthews-Pennanen, Neil. „Assessment of Potential Changes in Crop Yields in the Central United States Under Climate Change Regimes“. DigitalCommons@USU, 2018. https://digitalcommons.usu.edu/etd/7017.

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Climate change is one of the great challenges facing agriculture in the 21st century. The goal of this study was to produce projections of crop yields for the central United States in the 2030s, 2060s, and 2090s based on the relationship between weather and yield from historical crop yields from 1980 to 2010. These projections were made across 16 states in the US, from Louisiana in the south to Minnesota in the north. They include projections for maize, soybeans, cotton, spring wheat, and winter wheat. Simulated weather variables based on three climate scenarios were used to project future crop yields. In addition, factors of soil characteristics, topography, and fertilizer application were used in the crop production models. Two technology scenarios were used: one simulating a future in which crop technology continues to improve and the other a future in which crop technology remains similar to where it is today. Results showed future crop yields to be responsive to both the different climate scenarios and the different technology scenarios. The effects of a changing climate regime on crop yields varied both geographically throughout the study area and from crop to crop. One broad geographic trend was greater potential for crop yield losses in the south and greater potential for gains in the north. Whether or not new technologies enable crop yields to continue to increase as the climate becomes less favorable is a major factor in agricultural production in the coming century. Results of this study indicate the degree to which society relies on these new technologies will be largely dependent on the degree of the warming that occurs. Continued research into the potential negative impacts of climate change on the current crop system in the United States is needed to mitigate the widespread losses in crop productivity that could result. In addition to study of negative impacts, study should be undertaken with an interest to determine any potential new opportunities for crop development with the onset of higher temperatures as a result of climate change. Studies like this one with a broad geographic range should be complemented by studies of narrower scope that can manipulate climatic variables under controlled conditions. Investment into these types of agricultural studies will give the agricultural sector in the United States greater tools with which they can mitigate the disruptive effects of a changing climate.

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Boulidam, Somkhit Sansanee Choowaew. „Vulnerability and adaptation of rainfed-rice farmers to impact of climate variability in Lahakhok, Sebangnuane Tai, Dong Khamphou, and Houdhi villages of Songkhone district, Savannakhet province, Lao PDR /“. Abstract, 2005. http://mulinet3.li.mahidol.ac.th/thesis/2548/cd376/4637931.pdf.

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Craft, Kortney E. „Economic Impacts of Drought on Kentucky Corn, Hay, and Soybeans“. TopSCHOLAR®, 2011. http://digitalcommons.wku.edu/theses/1066.

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Understanding climatic impacts is important if we are to comprehend the relationship between climate and society. Weather phenomena can have environmental, economical, and social impacts. Drought is the natural hazard that affects people the most. It is also the most complex and least understood. There is no one universally accepted definition for drought which makes its examination difficult. Droughts’ duration is also difficult to determine because it has no clearly defined onset and end. Also, drought varies both geographically and temporally making uniform drought monitoring difficult. Since drought is difficult to monitor and access, drought impacts are often poorly documented. The purpose of this research was to quantify (in dollars) the impacts of drought on Kentucky’s agriculture. Drought has been recorded historically in Kentucky since the late 1800s. According to the Kentucky Climate Center, the most significant drought years occurred in 1930-31, 1940-42, and 1952-55. Analyses of these years are included as well as the most recent significant drought years in 1987-88, 1999- 2000 and 2007. Four of Kentucky’s important commodities, including corn, soybeans, hay, and beef cattle, were examined during the significant drought years. The total state revenue for these commodities was analyzed during severe drought years vs. non-severe drought years. The result of this research identified how much of a deficit severe drought causes on Kentucky revenue for each of these commodities. This research is important to the general public as well as planners and policy makers. Proper documentation of drought impacts will help identify drought vulnerabilities and result in better risk management and mitigation. Key Words: Drought, Agriculture, Impact Assessment

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Wiréhn, Lotten. „Climate Suitable Energy Crops and Biomass Energy Potentials : Assessment of the Current and Future Prospects in Estonia“. Thesis, Linköpings universitet, Tema Miljöförändring, 2010. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-116481.

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Development of biomass energy plantations is one approach to mitigate and adapt to climate change and the energy challenges related to it; however, climate change will affect the climate conditions and in turn the selection of crops and trees suitable for renewable energy sources. In Estonia, electricity is mainly based on oil shale but since their integration in the European Union they are required to increase the share of energy from renewable sources. In this study, the possible changes of suitable species are assessed by examining the current and the future prospects and potentials with biomass energy derived from energy plantations in Estonia, taking climate change into consideration. The biomass energy potentials for the species that are climate suitable in current and future time are manually estimated, using a case study approach when determining the yields. The study result suggests that biomass energy from crops and trees have great development possibilities and that climate is not a key limitation for the selection of suitable species; in addition, the energy crops and trees appear to suit the future climate conditions better than the current. The results indicate that the established national target of 25% of energy from renewable sources in gross final consumption of energy by 2020 could be achieved to a large extent by putting energy plantations into practice.

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Berhane, Daniel. „Development of methods and techniques for land resource surveying for Eritrea“. Pretoria : [s.n.], 2006. http://upetd.up.ac.za/thesis/available/etd-02162006-153034/.

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Tsang, Heung-chun, und 曾向俊. „The impact of the global-warming-led climate change on agricultural production of major grain producing regions in China“. Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2011. http://hub.hku.hk/bib/B46733048.

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ARDENTI, FEDERICO. „CONTRIBUTION OF AGROECOLOGICAL MEASURES TOWARDS CLIMATE-SMART AND MULTIFUNCTIONAL FARMING SYSTEMS“. Doctoral thesis, Università Cattolica del Sacro Cuore, 2023. http://hdl.handle.net/10280/135602.

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La continua crescita della popolazione mondiale, il progressivo degradamento dei suoli e il cambiamento climatico globale sono tra le più grandi sfide per l’umanità nel prossimo futuro. Pratiche non sostenibili di gestione del suolo e delle colture in agricoltura convenzionale hanno danneggiato lo stato di salute dell’agro-ecosistema e favorito il cambiamento climatico, attraverso la mineralizzazione della sostanza organica e il rilascio di forme reattive dell’azoto nelle acque e in atmosfera. L’adozione di nuove pratiche agricole sostenibili è stata indicata come una delle strade percorribili per l’adattamento dei sistemi agricoli ai cambiamenti climatici e per ridurre l’impatto negativo sull’ambiente. L’obiettivo principale di questa tesi è quello di valutare le performance delle pratiche sostenibili e clima-intelligenti (p.e., no-till, cover crop, e sub-irrigazione) in termini di potenziale produttivo delle colture, di incremento della qualità del suolo, e di riduzione dell’impatto climatico. Dai risultati emerge come le pratiche conservative (no-till e cover crop) siano in grado di generare rese colturali paragonabili ai sistemi convenzionali, mentre i sistemi irrigui efficienti (sub-irrigazione) siano particolarmente efficaci in condizioni climatiche siccitose. Inoltre, l’introduzione di queste pratiche agricole sostenibili ha consentito di preservare la qualità del suolo aumentandone il contenuto di azoto e carbonio e, allo stesso tempo, riducendo l’impatto climatico grazie al minor rilascio di nutrienti nell’ambiente.
Growing population, land degradation and climate change are significant threats to food security and human development. Conventional intensive farming is usually associated with soil quality depletion and environment pollution, through soil organic matter mineralization as carbon dioxide (CO2) and nitrogen release as reactive forms to atmosphere and water, thus promoting global climate change. The adoption of sustainable agroecosystems management is key for adapting to climate change while increasing soil quality and lowering agricultural impact on global warming. The main objective of this thesis is to evaluate the performances of climate-smart practices (i.e., no-till, cover crops, and subsurface drip irrigation) in terms of crop yield potential, soil quality increase and reduced impact on climate change. We concluded that conservation practices (no-till and cover crops) may ensure comparable crop yields to conventional system while high-efficient micro-irrigation systems (subsurface drip irrigation) are particularly effective under dry climate conditions. Moreover, such sustainable farming practices may (i) positively affect soil quality by enhancing carbon and nitrogen content into the soil, as well as (ii) reduce agricultural impact on climate change by lowering the release of nutrients to the environment.

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Gunathilaka, R. P. Dayani. „Economic impacts of climate change on perennial plantation tree crops: the case of tea production in Sri Lanka“. Thesis, Griffith University, 2018. http://hdl.handle.net/10072/377583.

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Agriculture is one sector of the economy which is highly vulnerable to climate change because of the natural relationship between environment, particularly temperature and water availability, and agricultural productivity. Changing climate is increasingly affecting high-value perennial plantation crops such as tea, rubber, coconut, palm oil, and coffee which generate significant export revenues and provide a major source of employment for rural populations in developing countries. Many studies in the literature have focused on climate change impacts on major annual crops; however, to date, there have been very few assessments of the economic impacts of climate change on perennial plantation agriculture. This thesis therefore seeks to estimate the impacts of climate change on two important aspects of plantation agriculture - crop production and labour demand - for the case of the tea plantation sector in Sri Lanka, as an example of a high-value perennial plantation crop in a developing country. The thesis also aims to identify enablers and barriers of adaptation to climate change for this sector of Sri Lanka’s economy. The impacts of climate change on production in Sri Lanka’s tea plantations are studied at estate-level (the primary decision making production unit) across all of the country’s tea growing regions using monthly resolution primary data for the period 2000-2014. The study employs a novel two-stage panel data approach to analyse weather and climate change effects on tea production and then to estimate production impacts for the short-, medium- and long-term future under three different global emissions scenarios. These analyses indicate that a hotter and wetter climate will have a detrimental effect on production. In high, medium and low emissions futures, the predictions show a negative proportional impact on production from increased rainfall and increased average temperature. On average across the data sample, a 12% decline in annual tea production is predicted under a high emissions scenario by 2050. The impacts of climate change on labour demand in tea plantations in Sri Lanka are investigated by implementing a panel structural model of profit maximisation based on a normalised quadratic functional form. The analysis uses historical primary data on estate profits, input prices and output prices, together with monsoonal rainfall, temperature and wet days for years between 2002-2014 to quantify climate impacts on estates’ demand for labour. Anticipated changes in rainfall are predicted to reduce annual labour demand by 2.6% across the tea plantation sector. This could have considerable social and welfare implications, particularly for the Indian Tamil women who comprise the majority of the sector’s workforce. Plantation agriculture is likely to be highly vulnerable to climate change because of its reliance on rain-fed production, long economic life span and the inability to easily switch crops due to high upfront capital costs. These distinct differences between annual and perennial agriculture, and the important role which plantation cropping plays in developing world agriculture, suggest that it is important to identify factors which affect choice of climate adaptation options in perennial crop production. Comprehensive knowledge of available adaptation options is of utmost importance if Sri Lanka’s tea estate managers are to counteract production losses from climate change and maintain their competitiveness in the international market. This is also vital for efficient and effective channeling of society’s resources to address the consequences of climate change. Employing data derived from face-to-face interviews with 50 tea estate managers in Sri Lanka, this study examines factors affecting choice of preferred adaptation options, barriers to adaptation and associated policy implications for tea production in Sri Lanka, as an example of a perennial tree crop system in a developing country. Tea estate managers are already adapting to a changing climate; however, particular adaptation methods are only adopted in some situations and locations. Multinomial logit analysis of data from estate manager interviews indicates that availability of information on climate change, company size, tea growing elevation, and observed increases in temperature and rainfall are key factors influencing the choice of preferred adaptation option. Analysis also finds that barriers such as a lack capital, inadequate access to near-term and medium-term climate knowledge, and poor governmental and institutional support may prevent estate managers from experimenting with new adaptation options. Policies should, therefore, be aimed at promoting new adaptation options through information exchange between stakeholders and integrating climate change adaptation with Sri Lanka’s national sustainable developmental goals. The primary message of the adaptation analysis in this study is that governmental and institutional support and involvement are critical requirements for facilitating effective adaptation. Findings from the thesis will help inform decision makers of the likely impacts of climate change on plantation cropping systems, and provide insights into barriers to adaptation and potential policy responses to improve the effectiveness of adaptation.
Thesis (PhD Doctorate)
Doctor of Philosophy (PhD)
School of Environment and Sc
Science, Environment, Engineering and Technology
Full Text

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Hayman, P. T. „Dancing in the rain : farmers and agricultural scientists in a variable climate /“. View thesis View thesis, 2001. http://library.uws.edu.au/adt-NUWS/public/adt-NUWS20030506.144613/index.html.

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Thesis (Ph.D.)--University of Western Sydney, Hawkesbury, 2001.
A thesis submitted to the Faculty of Environmental Management and Agriculture, University of Western Sydney, in fulfilment of the rquirements for the degree of Doctor of Philosophy, 2001. Bibliography : p. 252-276.

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Tabalaza, Nomthetho. „The impact climate change on rural households in Binfield village“. Thesis, Nelson Mandela Metropolitan University, 2017. http://hdl.handle.net/10948/20626.

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Climate change poses a major environmental challenge, due to its adverse effects on human settlement patterns and food security. The global phenomenon upsets seasonal shifts, leading to changes in planting dates and weather patterns. This unpredictability has severe and adverse effects on farmers and rural communities, as variable environmental factors govern activities related to daily sustenance and food availability. The kind of rapid and intense climate change that South African rural spaces are experiencing now, increase the likelihood of extreme weather events such as droughts, heat waves and floods. There are growing concerns that the rural poor will be unable to adapt. Rural livelihoods are therefore facing overwhelming and extensive environmental threats, while rural dwellers are finding it difficult to adapt and cope. As a result, climate change can thus be described as one of the most complex and dangerous environmental problems challenging rural livelihoods today. The aim of this study was to explore the impact of climate change on rural poverty at Binfield village in the Eastern Cape and to identify the livelihood activities practiced. Furthermore, the research was conducted to ascertain how rural livelihood activities are affected by climate change and identify and assess the effectiveness of adaption strategies employed by the households. The research also aimed to explore and establish further adaptation strategies. This study made use of a qualitative research method. Babooa (2008) argues that qualitative research is concerned with stories and accounts including subjective understandings, feelings, opinions and beliefs. The study used both primary and secondary data for data. The researcher adopted interviews and field observation for primary data whilst secondary data was sourced from journals, articles and internet sources. O‘ Leary (2004) describes the interview as a method of collecting data where the interviewer asks the Interviewee open-ended questions. The questions were based on the key areas of interest. Qualitative research methods are aimed at understanding the rich, complex characteristic nature of human phenomena. Qualitative methods are concerned with understanding human behaviour from the participant‘s own frame of reference.

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Mayom, Chol Permina. „Impact of Climate Change and Weather Variability on North Dakota Agriculture“. Thesis, North Dakota State University, 2008. https://hdl.handle.net/10365/29717.

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This study used county-level yields and panel data (1950-2006) to explain the Impact of climate change and weather variability on North Dakota agriculture by estimating the effect of variation in temperature and precipitation on the yields of four major crops: com, durum, soybeans and wheat. In addition to yields, the study examined Impacts of climate change on crop gross revenues per acre for all 53 counties in North Dakota. An econometric model was developed to infer statistical relationships between weather variability and crop yields. Fixed and random effects models were employed to estimate the impacts of climate variables (temperature and precipitation) on crop yields. The Hausman test statistics was applied to test the preferred panel estimation approach: fixed versus random effects. Using mean values of precipitation and degree days for all counties, we calculated percentage changes in estimated crop yields for six climate change scenarios. The historical price data for the four crops (com, soybeans, spring wheat and durum) were used to generate per acre gross returns under the six weather-change scenarios in order to provide preliminary evidence about the effects of precipitation and temperature changes on farmer returns for the four crops.

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Nhemachena, Charles. „Agriculture and future climate dynamics in Africa impacts and adaptation options /“. Thesis, Pretoria : [s.n.], 2009. http://upetd.up.ac.za/thesis/available/etd-05302009-122839/.

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Oosthuizen, Hamman Jacobus. „Modelling the financial vulnerability of farming systems to climate change in selected case study areas in South Africa“. Thesis, Stellenbosch: Stellenbosch University, 2014. http://hdl.handle.net/10019.1/95831.

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Thesis (PhD)--Stellenbosch University, 2014.
ENGLISH ABSTRACT: Numerous studies indicate that the agricultural sector is physically and economically vulnerable to climate change. In order to determine possible impacts of projected future climates on the financial vulnerability of selective farming systems in South Africa, a case study methodology was applied. The integrated modelling framework consists of four modules, viz.: climate change impact modelling, dynamic linear programming (DLP) modelling, modelling interphases and financial vulnerability assessment modelling. Empirically downscaled climate data from five global climate models (GCMs) served as base for the integrated modelling. The APSIM crop model was applied to determine the impact of projected climates on crop yield for certain crops in the study. In order to determine the impact of projected climates on crops for which there are no crop models available, a unique modelling technique, Critical Crop Climate Threshold (CCCT) modelling, was developed and applied to model the impact of projected climate change on yield and quality of agricultural produce. Climate change impact modelling also takes into account the projected changes in irrigation water availability (ACRU hydrological model) and crop irrigation requirements (SAPWAT3 model) as a result of projected climate change. The model produces a set of valuable results, viz. projected changes in crop yield and quality, projected changes in availability of irrigation water, projected changes in crop irrigation needs, optimal combination of farming activities to maximize net cash flow, and a set of financial criteria to determine economic viability and financial feasibility of the farming system. A set of financial criteria; i.e. internal rate of return (IRR), net present value (NPV), cash flow ratio, highest debt ratio, and highest debt have been employed to measure the impact of climate change on the financial vulnerability of farming systems. Adaptation strategies to lessen the impact of climate change were identified for each case study through expert group discussions, and included in the integrated modelling as alternative options in the DLP model. This aims at addressing the gap in climate change research, i.e. integrated economic modelling at farm level; thereby making a contribution to integrated climate change modelling.
AFRIKAANSE OPSOMMING: Die fisiese sowel as ekonomiese kwesbaarheid van die landbousektor as gevolg van klimaatverandering word deur verskeie studies beklemtoon. ‘n Gevallestudie-benadering is gebruik ten einde die potensiële impak van klimaatsverandering op die finansiële kwesbaarheid van verskillende boerderystelsels te bepaal. Die geïntegreerde klimaatsveranderingmodel bestaan uit vier modelleringsmodules, naamlik: klimaatsverandering, dinamiese liniêre programmering (DLP), interfases en finansiële-kwesbaarheidsontleding. Empiries afgeskaalde klimatologiese data van vyf verskillende klimaatmodelle dien as basis vir die geïntegreerde klimaatsveranderingmodel. Die APSIM gewas-model word aangewend om die impak van klimaatsverandering op gewasse-opbrengs te bepaal. Vir sekere gewasse is daar egter nie modelle beskikbaaar nie en het gevolglik die ontwikkeling van ‘n nuwe model genoodsaak. Die Kritiese Gewasse Klimaatsdrempelwaarde (KGKD) modelleringstegniek is ontwikkel ten einde die impak van klimaatsverandering op die opbrengs en kwaliteit van gewasse te kwantifiseer. Die geïntegreerde klimaatsveranderingmodel neem ook die verwagte verandering in besproeiingswaterbeskikbaarheid (ACRU-hidrologiemodel) en gewas-besproeiingsbehoeftes (SAPWAT3-model) as gevolg van klimaatsverandering in ag. Die model lewer waardevolle resultate op, naamlik: geprojekteerde veranderinge in gewasse-opbrengs en -kwaliteit, geprojekteerde verandering in beskikbaarheid van besproeiingswater en gewasse-besproeiingsbehoeftes, die optimale kombinering van boerdery-aktiwiteite om netto kontantvloei te maksimeer, asook ‘n stel finansiële resultate wat die impak van klimaatsverandering kwantifiseer. Die finansiële kriteria sluit in: interne opbrengskoers, netto huidige waarde, kontanvloeiverhouding, hoogste skuldverhouding en hoogste skuldvlak. Deur middel van deskundige-groepbesprekings is aanpassingstrategieë vir elk van die gevallestudies geïdentifiseer en by die geïntegreerde model ingesluit as alternatiewe opsies in die DLP-model. Die studie poog om die gaping in die huidige klimaatsveranderingnavorsing met betekking tot ‘n geïntegreerde ekonomiese model op plaasvlak aan te spreek en sodoende ‘n bydrae tot geïntegreerde klimaatveranderingmodellering te maak.

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Woldetsadik, Kebede. „Shallot (Allium cepa var. ascolonicum) responses to plant nutrients and soil moisture in a sub-humid tropical climate /“. Alnarp : Dept. of Crop Science, Swedish Univ. of Agricultural Sciences, 2003. http://epsilon.slu.se/a367.pdf.

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Vagh, Yunous. „Mining climate data for shire level wheat yield predictions in Western Australia“. Thesis, Edith Cowan University, Research Online, Perth, Western Australia, 2013. https://ro.ecu.edu.au/theses/695.

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Climate change and the reduction of available agricultural land are two of the most important factors that affect global food production especially in terms of wheat stores. An ever increasing world population places a huge demand on these resources. Consequently, there is a dire need to optimise food production. Estimations of crop yield for the South West agricultural region of Western Australia have usually been based on statistical analyses by the Department of Agriculture and Food in Western Australia. Their estimations involve a system of crop planting recommendations and yield prediction tools based on crop variety trials. However, many crop failures arise from adherence to these crop recommendations by farmers that were contrary to the reported estimations. Consequently, the Department has sought to investigate new avenues for analyses that improve their estimations and recommendations. This thesis explores a new approach in the way analyses are carried out. This is done through the introduction of new methods of analyses such as data mining and online analytical processing in the strategy. Additionally, this research attempts to provide a better understanding of the effects of both gradual variation parameters such as soil type, and continuous variation parameters such as rainfall and temperature, on the wheat yields. The ultimate aim of the research is to enhance the prediction efficiency of wheat yields. The task was formidable due to the complex and dichotomous mixture of gradual and continuous variability data that required successive information transformations. It necessitated the progressive moulding of the data into useful information, practical knowledge and effective industry practices. Ultimately, this new direction is to improve the crop predictions and to thereby reduce crop failures. The research journey involved data exploration, grappling with the complexity of Geographic Information System (GIS), discovering and learning data compatible software tools, and forging an effective processing method through an iterative cycle of action research experimentation. A series of trials was conducted to determine the combined effects of rainfall and temperature variations on wheat crop yields. These experiments specifically related to the South Western Agricultural region of Western Australia. The study focused on wheat producing shires within the study area. The investigations involved a combination of macro and micro analyses techniques for visual data mining and data mining classification techniques, respectively. The research activities revealed that wheat yield was most dependent upon rainfall and temperature. In addition, it showed that rainfall cyclically affected the temperature and soil type due to the moisture retention of crop growing locations. Results from the regression analyses, showed that the statistical prediction of wheat yields from historical data, may be enhanced by data mining techniques including classification. The main contribution to knowledge as a consequence of this research was the provision of an alternate and supplementary method of wheat crop prediction within the study area. Another contribution was the division of the study area into a GIS surface grid of 100 hectare cells upon which the interpolated data was projected. Furthermore, the proposed framework within this thesis offers other researchers, with similarly structured complex data, the benefits of a general processing pathway to enable them to navigate their own investigations through variegated analytical exploration spaces. In addition, it offers insights and suggestions for future directions in other contextual research explorations.

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Porter, William Christian. „Air-quality and Climatic Consequences of Bioenergy Crop Cultivation“. PDXScholar, 2013. https://pdxscholar.library.pdx.edu/open_access_etds/1042.

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Bioenergy is expected to play an increasingly significant role in the global energy budget. In addition to the use of liquid energy forms such as ethanol and biodiesel, electricity generation using processed energy crops as a partial or full coal alternative is expected to increase, requiring large-scale conversions of land for the cultivation of bioenergy feedstocks such as cane, grasses, or short rotation coppice. With land-use change identified as a major contributor to changes in the emission of biogenic volatile organic compounds (BVOCs), many of which are known contributors to the pollutants ozone (O3) and fine particulate matter (PM2.5), careful review of crop emission profiles and local atmospheric chemistry will be necessary to mitigate any unintended air-quality consequences. In this work, the atmospheric consequences of bioenergy crop replacement are examined using both the high-resolution regional chemical transport model WRF/Chem (Weather Research and Forecasting with Chemistry) and the global climate model CESM (Community Earth System Model). Regional sensitivities to several representative crop types are analyzed, and the impacts of each crop on air quality and climate are compared. Overall, the high emitting crops (eucalyptus and giant reed) were found to produce climate and human health costs totaling up to 40% of the value of CO2 emissions prevented, while the related costs of the lowest-emitting crop (switchgrass) were negligible.

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Mdoda, Lelethu. „Farmers’ awareness of climate change and variability and it’s effects on agricultural productivity: (the case of King Sabata Dalindyebo Municipalty in Eastern Cape)“. Thesis, University of Fort Hare, 2014. http://hdl.handle.net/10353/d1021294.

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Climate is an important factor of agricultural productivity and many rural dwellers in developing countries depend on agriculture and are highly affected by climate change and variability. The world is currently experiencing climatic changes and variability conditions which results in high temperatures, low rainfall patterns, shortage of water and drought persistence. Climate change and variability is affecting weather patterns and shifting seasons which results in serious repercussions on smallholder farmers. Smallholder farmers are extremely vulnerable to climate change and variability because their farming and production systems are climate sensitive and are not rebound to climate stresses. These adverse effects in developing countries arise from different climate change and variability-related causes, notable extreme weather events, food security, increased health risks in agriculture from vector home diseases, and temperature-related morbidity in environments. The study was carried in King Sabata Dalindyebo Municipality in the Eastern Cape Province in South Africa. This study examines farmers’ awareness of climate change and variability and its effects on agricultural productivity in King Sabata Dalindyebo municipality using a Descriptive Statistics, Binary and Ricardian Model fitted to data from a cross-sectional survey of 200 farmers in King Sabata Dalindyebo Municipality. Both primary and secondary data was used. This research study estimates the effects of climate change and variability on King Sabata Dalindyebo agricultural productivity using a continental dimension of Ricardian analysis. Results revealed that local farmers were aware of climate change and variability and perceived changes in average temperatures and rainfall. The changes in average temperatures and rainfall had adverse effects on crop and livestock production. However, farmers’ awareness of climate change is not to an extent that they presume adaptation to climate change as a necessity and crucial. The results show that climate change and variability affects farm income and there is a non-linear relationship existing between climatic variables (temperature and precipitation) and farm income which depicts U-shaped. The study results indicated that climate change and variability affect agricultural productivity and have an effect on agricultural productivity in King Sabata Dalindyebo Municipality. In view of the research findings, several policy proposals are suggested. The study findings suggest that climate change and variability must be taken seriously and monitored. Policy makers and government officials must support farmers with information distribution,education, market access, well trained extension agents, credit and information about mitigation strategies to climate change and variability which includes institutional and technological methods, particularly smallholder farmers.

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Arango, Argoti Miguel Andres. „Nitrous oxide emissions: measurements in corn and simulations at field and regional scale“. Diss., Kansas State University, 2013. http://hdl.handle.net/2097/16680.

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Doctor of Philosophy
Department of Agronomy
Charles W. Rice
Nitrogen is critical for plant growth and is a major cost of inputs in production agriculture. Too much nitrogen (N) is also an environmental concern. Agricultural soils account for 85% of anthropogenic N₂O which is a major greenhouse gas. Management strategies for N fertilization and tillage are necessary for enhancing N use efficiency and reducing negative impacts of N to the environment. The different management practices induce changes in substrate availability for microbial activity that may result in increasing or reducing net N₂O emitted from soils. The objectives of this research were to (1) integrate results from field studies to evaluate the effect of different management strategies on N₂O emissions using a meta-analysis, (2) quantify N₂O-N emissions under no-tillage (NT) and tilled (T) agricultural systems and the effect of different N source and placements, (3) perform sensitivity analysis, calibration and validation of the Denitrification Decomposition (DNDC) model for N₂O emissions, and (4) analyze future scenarios of precipitation and temperature to evaluate the potential effects of climate change on N₂O emissions from agro-ecosystems in Kansas. Based on the meta-analysis there was no significant effect of broadcast and banded N placement. Synthetic N fertilizer usually had higher N₂O emission than organic N fertilizer. Crops with high N inputs as well as clay soils had higher N₂O fluxes. No-till and conventional till did not have significant differences regarding N₂O emissions. In the field study, N₂O-N emissions were not significantly different between tillage systems and N source. The banded N application generally had higher emissions than broadcasted N. Slow release N fertilizer as well as split N applications reduced N₂O flux without affecting yield. Simulations of N₂O emissions were more sensitive to changes in soil parameters such as pH, soil organic carbon (SOC), field capacity (FIELD) and bulk density (BD), with pH and SOC as the most sensitive parameters. The N₂O simulations performed using Denitrification Decomposition model on till (Urea) had higher model efficiency followed by no-till (compost), no-till (urea) and till (compost). At the regional level, changes in climate (precipitation and temperature) increased N₂O emission from agricultural soils in Kansas. The conversion from T to NT reduced N₂O emissions in crops under present conditions as well as under future climatic conditions.

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Rodjom, Abbey Michaella. „Coproduction of Biomass Crops and Anaerobic Digestion: Effects on the Life Cycle Emissions of Bioenergy and Bioproducts“. Ohio University / OhioLINK, 2021. http://rave.ohiolink.edu/etdc/view?acc_num=ohiou1610664975665256.

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Steffen, Edwin, und Silvia Bergknecht. „Futterpflanzen und Klimawandel : Bewertung von Arten und Sorten landwirtschaftlicher Futterpflanzen in ihrer Reaktion auf veränderte klimatische Bedingungen“. Saechsische Landesbibliothek- Staats- und Universitaetsbibliothek Dresden, 2006. http://nbn-resolving.de/urn:nbn:de:swb:14-1165231609815-56935.

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Bhatasara, Sandra. „Understanding climate variability and livelihoods adaptation in rural Zimbabwe : case of Charewa, Mutoko“. Thesis, Rhodes University, 2015. http://hdl.handle.net/10962/d1018928.

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Rural farmers in Zimbabwe have been grappling with various changes and challenges occurring in the country since the early 1990s. Amongst these, climate variability has emerged as one significant aspect. It has introduced new challenges for these farmers who are already facing various difficulties in maintaining their insecure livelihoods. Yet, current adaptation theories and inquiries have failed to sufficiently account for and analyse the capacity of these farmers to adequately respond to changing climatic conditions. In this respect, a number of studies have been heavily embedded in deterministic concepts that regard rural farmers as passive victims who play only a minor part in decisions and actions that affect their own livelihoods and well-being. Similarly, although some studies have acknowledged farmers’ capacity to adapt and build elements of resilience, they have not adequately shown how farmers interpret changes in climate and the structures, processes and conditions underpinning adaptation. Following that, my study uses a case study of a rural community in a semi-arid region of Mutoko district in eastern Zimbabwe and Margaret Archer’s sociological theory to understand and analyse how farmers problematise climate variability and respond to it. The study utilises a qualitative approach to divulge the subtleties on how rural people interpret processes of change and adapt to such changes. The thesis found that farmers are encountering increasingly unpredictable and unreliable rainfall patterns as well as shifting temperature conditions which are inducing labyrinthian livelihoods conundrums. However, these climatic shifts are not being experienced in a discrete manner hence farmers are also discontented with the obtaining socio-economic circumstances in the country. Simultaneously, whilst farmers in large part conceived changes in rainfall and temperature to be caused by natural shifts in climate, they also ascribed them to cultural and religious facets. Importantly, the thesis reveals considerable resourcefulness by farmers in the face of nascent changes in climate variability. Farmers have therefore constructed versatile coping and adaptive strategies. What is crucial to mention here is that climatic and non-climatic challenges are negotiated concurrently. Therein, farmers are adapting to climate variability and at the same time navigating difficult socio-economic landscapes. All the same, the process of adaptation is ostensibly not straightforward but complex. As it evolves, farmers find themselves facing numerous constraining structures and processes. Nonetheless, farmers in this study are able to circumvent the constraints presented to them and at the same time activate the corresponding enabling structures, processes and conditions.

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Wan, Shen. „Phytoremediation of Nitrous Oxide: Expression of Nitrous Oxide Reductase from Pseudomonas Stutzeri in Transgenic Plants and Activity thereof“. Thèse, Université d'Ottawa / University of Ottawa, 2012. http://hdl.handle.net/10393/20661.

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As the third most important greenhouse gas, nitrous oxide (N2O) is a stable greenhouse gas and also plays a significant role in stratospheric ozone destruction. The primary anthropogenic source of N2O stems from the use of nitrogen in agriculture, with soils being the major contributors. Currently, the annual N2O emissions from this “soil–microbe-plant” system is more than 2.6 Tg (one Tg equals a million metric tons) of N2O-N globally. My doctoral studies aimed to explore innovative strategies for N2O mitigation, in the context of environmental microbiology’s potential contribution to alleviating global warming. The bacterial enzyme nitrous oxide reductase (N2OR), naturally found in some soils, is the only known enzyme capable of catalyzing the final step of the denitrification pathway, conversion of N2O to N2. Therefore, to “scrub” or reduce N2O emissions, bacterial N2OR was heterologously expressed inside the leaves and roots of transgenic plants. Others had previously shown that the functional assembly of the catalytic centres (CuZ) of N2OR is lacking when only nosZ is expressed in other bacterial hosts. There, coexpression of nosZ with nosD, nosF and nosY was found to be necessary for production of the catalytically active holoenzyme. I have generated transgenic tobacco plants expressing the nosZ gene, as well as tobacco plants in which the other four nos genes were coexpressed. More than 100 transgenic tobacco lines, expressing nosZ and nosFLZDY under the control of rolD promoter and d35S promoter, have been analyzed by PCR, RT-PCR and Western blot. The activity of N2OR expressed in transgenic plants, analyzed with the methyl viologen-linked enzyme assay, showed detectable N2O reducing activity. The N2O-reducing patterns observed were similar to that of the positive control purified bacterial N2OR. The data indicated that expressing bacterial N2OR heterologously in plants, without the expression of the accessory Nos proteins, could convert N2O into inert N2. This suggests that atmospheric phytoremediation of N2O by plants harbouring N2OR could be invaluable in efforts to reduce emissions from crop production fields.

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Nyaga, James Njogu <1983&gt. „Assessment of Perceived impacts of climate change on agricultural crops productions and its effects on food security: A case study of small-scale farmers in Murang’a County Kenya“. Master's Degree Thesis, Università Ca' Foscari Venezia, 2021. http://hdl.handle.net/10579/19853.

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Ribeiro, Rita da Mata. „Agroenergia na mitigação das mudanças climáticas globais, na segurança energética e na promoção social“. Universidade Federal de Viçosa, 2009. http://locus.ufv.br/handle/123456789/4517.

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Made available in DSpace on 2015-03-26T13:39:34Z (GMT). No. of bitstreams: 1 texto completo.pdf: 4547948 bytes, checksum: a4e6166dd7e07196209bfe8285680cb5 (MD5) Previous issue date: 2009-08-27
Coordenação de Aperfeiçoamento de Pessoal de Nível Superior
Agroenergy has a strategic role in the mitigation of Greenhouse Effect Gases (GEG), in energy security and in social movements. Two equally important factors rekindle the world-wide interest for renewable energies sources, especially those originating from biomass: i) the current perspective of the depletion of non-renewable energy reserves and ii) the negative scenarios of global climatic changes (GCCs), caused by global warming. This last factor has a strong relation to burning fossil fuels, which accounts for 75 % of the GEG emissions, and with the current form of use and occupation of land, as reported by the Intergovernmental Panel on Climate Changes (IPCC). In this context, renewable energy alternatives are primary in confronting such challenges. The present work is sectioned into three chapters, each intimately connected. The first two were based on the exploratory research documentation. To do this parameters and information relative to the IPCC and its implications were used, especially on agriculture, and global agroenergy programs, such as the National Program of Production and Use of Biodiesel (PNPB). Biodiesel appears to be a promising alternative in the partial substitution of petro-derivatives and in the mitigation of GCCs, besides other advantages that qualify it in a favorable global scenario. The spread in the participation of biodiesel in a favorable world-wide energy matrix creates an opportunity to execute policies in the following areas: social (generation of jobs and income and the reduction of regional asymmetries), environmental (reduction of GEGs) and economical (import reductions of petrodiesel and exchange factor). Agrofuels represent an important instrument of development, especially for countries that signed the Kyoto Protocol agreement, in effect until 2012 and, in the future, the Copenhagen Protocol, which will be implemented after 2012. Among the producing countries, Brazil presents the greatest conditions to lead energy agriculture on a world-wide scale. The third chapter is based on a questionnaire answered by Biodiesel Production Factories (BPFs) in Brazil, after the introduction of the PNPB. The inquiry also was supported in secondary sources, such as books, maps and the web. The data of the National Agency of Oil, Natural gas and Biofuels (ANP) were used as parameters. The most used raw materials in the production of biodiesel in the country are soy (main), animal fat, and the cotton and castor seed, in this order, and with a great interest in the fisic nut. The methyl route is the most used, being adopted by 53 % of the BPFs in study. Within the premise of the PNPB, the Social Fuel Seal (SCS) is an important component to stimulate the introduction of the BPFs. The PNPB presents advancements like the insertion of biodiesel into the Brazilian energy matrix, generation of jobs, income and regional development, especially in the Northeast and in the semi-arid regions. However, there are still many challenges to be faced, like the subsidies and protectionism of the biodiesel production countries, especially the USA and EU.
A agroenergia tem papel estratégico na mitigação dos Gases de Efeito Estufa (GEE), na segurança energética e na promoção social. Dois fatores igualmente importantes reacendem o interesse mundial por fontes de energias renováveis, notadamente, aqueles provenientes da biomassa: i) a atual perspectiva de esgotamento das reservas energéticas não-renováveis e ii) os cenários negativos das mudanças climáticas globais (MCGs), causadas pelo aquecimento global. Este último fator tem forte relação com a queima de combustíveis fosséis, os quais respondem por 75% das emissões de GEE, e com a forma atual de uso e ocupação do solo, conforme reportado pelo Painel Intergovernamental sobre Mudanças do Clima (IPCC). Neste contexto, alternativas energéticas renováveis são primordiais para o enfrentamento de tais desafios. O presente trabalho está formatado em três capítulos, intimamente relacionados. Os dois primeiros basearam-se na pesquisa exploratória documental. Para tanto foram utilizados como parâmetros dados e informações relativas ao IPCC e suas implicações, notadamente sobre a agricultura, e dos programas globais de agroenergia, a exemplo do Programa Nacional de Produção e Uso de Biodiesel (PNPB). O biodiesel surge como alternativa promissora na substituição parcial dos petroderivados e na mitigação das MCGs, além de outras vantagens que o qualifica em um cenário favorável globalmente. A ampliação da participação do biodiesel na matriz energética mundial propicia a oportunidade de executar políticas nos âmbitos: social (geração de emprego e renda e redução das assimetrias regionais), ambiental (redução de GEE) e econômico (redução de importações de petrodiesel e fator de divisas). Os agrocombustíveis representam importante instrumento de desenvolvimento, especialmente para países signatários do acordo firmado pelo Protocolo de Quioto, vigente até 2012 e, futuramente, pelo Protocolo de Copenhague, a ser implementado após 2012. Dentre os países produtores, o Brasil apresenta maiores condições para liderar a agricultura de energia em escala mundial. O terceiro capítulo baseou-se em um questionário respondido por Usinas Produtoras de Biodiesel (UPBs) do Brasil, após a implantação do PNPB. A pesquisa também se apoiou em fontes secundárias, como livros, mapas e web. Os dados da Agência Nacional de Petróleo, Gás Natural e Biocombustíveis (ANP) foram utilizados como parâmetros. As matérias-primas mais utilizadas na produção de biodiesel no país são a soja (majoritariamente), a gordura animal, o caroço de algodão e a mamona, nessa ordem, e com grande interesse pelo pinhão-manso. A rota metílica é a mais utilizada, sendo adotada por 53% das UPBs em estudo. Dentro das premissas do PNPB, o Selo Combustível Social (SCS) é um componente importante como incentivador da implantação das UPBs. O PNPB apresenta avanços, como a inserção do biodiesel na matriz energética brasileira, geração de emprego, renda e desenvolvimento regional, notadamente no Nordeste e nas regiões semiáridas. Porém ainda apresenta muitos desafios a serem enfrentados, a exemplo dos subsídios e protecionismos dos países produtores de biodiesel, especialmente dos EUA e UE.

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Perdomo, López Juan Alejandro. „Acclimation of photosynthesis to water deficit and high temperature: physiological and biochemical aspects“. Doctoral thesis, Universitat de les Illes Balears, 2015. http://hdl.handle.net/10803/291688.

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La demanda mundial de cultivos agrícolas para la alimentación ha experimentado un aumento notorio a través de las últimas décadas como consecuencia de la creciente población humana. Por otra parte, las predicciones globales de cambio climático predicen aumentos de temperatura y períodos de sequía más largos, especialmente en latitudes templadas, donde se encuentra la mayor parte de la producción mundial de cultivos. El presente estudio se llevó a cabo con tres de los cultivos más importantes a nivel mundial: arroz (Oryza sativa L.), trigo (Triticum aestivum L.) y maíz (Zea mays L.). Además de tres de los cultivos más demandados a nivel mundial, estas tres especies también fueron escogidas debido a sus diferentes mecanismos fotosintéticos, y a las diferentes condiciones ambientales a las que están adaptadas. De esta manera, el arroz y el trigo son especies C3 de ambientes cálidos y fríos, respectivamente, y el maíz es una especie C4 de ambientes cálidos. Con el objetivo de evaluar la respuesta de estos tres cultivos a las tensiones derivadas del cambio climático, es decir, alta temperatura y la sequía, las plantas se cultivaron a 38ºC y 25ºC, y dentro de cada temperatura, un lote de plantas era cultivado bajo condiciones de déficit hídrico (WD) y otro, como bajo capacidad de campo (WW). En todos los casos, se midieron los parámetros de crecimiento, fisiológicos y bioquímicos con el fin de evaluar el efecto de los dos estreses impuestos. Con relación a los parámetros fisiológicos, como la asimilación de CO2 y los procesos difusivos, estos se midieron a 25ºC y 38ºC para determinar la capacidad de estos cultivos para adaptarse y aclimatarse a la alta temperatura y el déficit hídrico. Ambas tensiones tuvieron un efecto negativo sobre las plantas, pero el impacto fue diferente dependiendo de los parámetros medidos. La alta temperatura tuvo un mayor efecto perjudicial en la producción de biomasa y la respiración mitocondrial, especialmente en trigo y maíz. En cambio, en las tres especies, la capacidad fotosintética y los parámetros de difusión como gs mostraron una mayor restricción bajo déficit de agua que a alta temperatura. Con respecto a las mediciones bioquímicas, los parámetros de Rubisco in vitro mostraron la misma tendencia que AN, mientras que la actividad Rubisco, la concentración y el estado carbamilación fueron más afectados por las altas temperaturas que por el déficit hídrico. Finalmente, algunos de los parámetros medidos en esta tesis sólo mostraron un efecto negativo cuando ambas tensiones actuaron conjuntamente. Esto indica la importancia de estudiar la interacción entre estos dos estreses.

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Lindner, Steve [Verfasser], und Dennis [Akademischer Betreuer] Otieno. „Determining the Role of Agro-Ecosystems in a Changing Climate : Quantification of CO2 exchange, Carbon allocation and Storage in the Main Agricultural Crops of South Korea / Steve Lindner. Betreuer: Dennis Otieno“. Bayreuth : Universität Bayreuth, 2016. http://d-nb.info/1108406114/34.

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Бурлак, К. С., und Є. В. Петрушевець. „Перспективи використання Сосни чорної (австрійської) в умовах зміни клімату на прикладі Красилівського лісництва ДП «Чернігівське лісове господарство»“. Thesis, Чернігів, 2021. http://ir.stu.cn.ua/123456789/25105.

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Бурлак, К. С. Перспективи використання Сосни чорної (австрійської) в умовах зміни клімату на прикладі Красилівського лісництва ДП «Чернігівське лісове господарство» : випускна комплексна кваліфікаційна робота : 205 «Лісoве гoспoдарствo» / К. С. Бурлак, Є. В. Петрушевець ; керівник роботи О. М. Корма ; НУ "Чернігівська політехніка", кафедра аграрних технологій та лісового господарства. – Чернігів, 2021. – 93 с.
Кваліфікаційна робота «Перспективи використання Сосни чорної (австрійської) в умовах зміни клімату на прикладі Красилівського лісництва ДП «Чернігівське лісове господарство»» присвячена проблемі всихання соснових лісів в умовах зміни клімату та пошуку альтернативних видів основних лісотвірних порід. Авторами проаналізовано стан вивчення питання на основі 70 літературних джерел, 2 з яких іноземною мовою. В ході дослідження авторами було розраховано необхідну кількість посадкового матеріалу, витрати по посадці лісових культур та вирощуванню сіянців для власних потреб.
Qualification work «Prospects for the use of black (Austrian) pine in climate change on the example of Krasyliv forestry SE «Chernihiv Forestry»» is devoted to the problem of drying of pine forests in climate change and the search for alternative species of major forest species. The authors analyzed the state of study of the issue on the basis of 70 literature sources, 2 of which are in a foreign language. During the study, the authors calculated the required amount of planting material, the cost of planting forest crops and growing seedlings for their own needs.

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Enquist, Tina. „Jordbrukets betydelse för det hållbara samhället : med fokus på klimatfrågan i Västerbottens län“. Thesis, Umeå universitet, Institutionen för ekologi, miljö och geovetenskap, 2018. http://urn.kb.se/resolve?urn=urn:nbn:se:umu:diva-150160.

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The purpose of this study was to investigate how farmers in the region of Västerbotten work for a sustainable development according to climate change, and where resources could be put in place to make agriculture even more climate friendly. The method chosen was a qualitative interview study where eight farmers from the county were interviewed. Half of them had an ecological production, and the other half was conventional. All the interviews were recorded, and the raw data was put in a database in Excel and analyzed. The results showed differences between ecological and conventional production systems, such as which agricultural practice that was the most sustainable in the future. Many farmers described several ways of decreasing their own climate burden by changing to LED light bulbs, Eco driving, spring plowing and raising their cattle in an intensive system. The future for agriculture was hard to speculate about, but faith in politicians played a crucial role. There were thoughts about both moving backwards to family-oriented agriculture and to increase the animal units with big industry-like settings. Overall, my own conclusion states that agriculture should be more circular to be sustainable, and that the society should be more involved in this circularity for it to work. Intensively raised cattle fed with less concentrate, and less imported meat, seems like a sustainable production. The agriculture of the future should be close to nature but at the same time modern, and we must protect our countryside if we want to have a sustainable society.

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Biernath, Christian Jörg [Verfasser], Jean Charles Akademischer Betreuer] Munch, Eckart [Akademischer Betreuer] Priesack und Andreas [Akademischer Betreuer] [Fangmeier. „Modeling climate change impacts on the yield and quality of crops based on leaf photosynthesis with the acclimation to elevated CO₂ / Christian Jörg Biernath. Gutachter: Eckart Priesack ; Jean Charles Munch ; Andreas Fangmeier. Betreuer: Jean Charles Munch“. München : Universitätsbibliothek der TU München, 2013. http://d-nb.info/1034951874/34.

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Ezekannagha, Ezinwanne. „Assessing the climatic suitability of Bambara groundnut as an underutilised crop to future climate projections in Sikasso and Ségou, Mali“. Master's thesis, Faculty of Science, 2020. http://hdl.handle.net/11427/32612.

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This study evaluates how future climatic projections will affect the suitability of bambara groundnut (Vigna subterranean(L) Verdc.), a type of underutilised crop in Sikasso and Ségou, southern Mali. This study was performed using a simulation approach, which considered the potential changes in suitability due to projected changes in two climate variables; temperature and precipitation. Monthly outputs of the two climate variables from 10 CORDEX bias-corrected regional projections under the Representative Concentration Pathway (RCP) 8.5 were applied. The suitability index range of bambara groundnut was projected, using the Ecocrop suitability model, considering three time periods: historical (1975-2005), near-term (2011-2040), and end of century (2070-2099). The results of this study showed that the model captured a long planting window for the crop in the regions across the time periods. With the projected increase in future climatic conditions, the suitability index range of bambara groundnut is projected to increase across the months suitable for planting the crop. Furthermore, Sikasso is projected to maintain a high suitability index in the near-term, and by the end of century, Ségou is expected to experience a potential increase in suitability index range and suitable areas, especially by the end of century. The results indicate that the CORDEX projections and suitability modelling technique applied in the study captured well the suitability of bambara groundnut in the regions which can help the farmers in making planting decisions. These results suggest an opportunity for optimal utilisation of the crop in the regions, as with a long planting window and expansion in suitable areas, farmers in the regions can plant multiple times and have more suitable areas to cultivate. This study contributes to improving the decision-making surrounding the promotion of underutilised crops as part of the strategy for climate-resilient agriculture and food security in Sikasso and Ségou.

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Gummadi, Sridhar. „Simulating the impacts of extreme climate events on crop productivity in current and future climates in India“. Thesis, University of Reading, 2011. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.553635.

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We need to understand the impacts of climate variability and change at a regional level on crop productivity in order to develop response strategies to the changing climate. This thesis seeks to investigate the impacts of extreme climate events on crops in current and future climates in India. The response of observed yield to present day climate variability was examined. Paddy rice and groundnut yields had a significant positive correlation with rainfall (r = 0.40, p < 0.05), while maximum temperature showed a strong negative relationship (-0.45); no such relationship was found for maize. The EPIC crop model simulated yields over regions of India were evaluated by forcing with observed climate data. Simulated yields were within ±20% of observed yields, significant positive correlations were noted between the EPIC simulated and detrended observed crop yields (paddy rice 0.38; groundnut 0.40 and maize 0.29). Significant negative relationships were found between yield and extreme precipitation (above 50 mm/day) and maximum temperature (above 33°C). Global coupled climate models (HadCM3, GFDL 2.1 and ECHAM5) were used to assess impacts of the SRES A2 projected future emission scenario on yield. Yields were 40% lower compared with IMD-forced values due to poor representation of the current climate. The PRECIS Regional Climate Model was used to examine the impact of the SRES A2 scenario in more detail at the regional scale. Groundnut and maize yield decreased by 40%, while paddy rice yield decreased by 35%.

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Davies-Barnard, T. „Climate and crop interactions : the biogeophysical effects on climate and vegetation“. Thesis, University of Bristol, 2014. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.685042.

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The interactions between changing agricultural land and climate are multi faceted and only partially understood. This thesis looks at interactions between crops and climate from assumptions about parameterisations that underpin crop changes in models; the unintended consequences of policies which affect land cover; and the impacts of deliberate crop changes (e.g. biogeoengineering). Focusing on the biogeophysical effects (from albedo, evapotranspiration etc.) these effects are compared to the biogeochemical effects (from greenhouse gases). There are considerable local and global biogeophysical effects to climate from land-use change, which do not necessarily scale linearly with the amount of landuse change itself. Changing the parameterisation of contributory factors to biogeophysical changes can affect the climate at least as much as deliberate alterations. Similarly, climate forced land cover change effects can be larger than land use forced changes. Increases in crop yield from deliberately altered albedo are small, but the changes to climate via albedo from different assumptions of yield are significant at a global and regional scale. This work emphasises the importance of including biogeophysical interactions in assessments of crop and land cover change in policy decisions, but also that the effects of land use change should not be overestimated, as the net effects are often smaller than the parameter uncertainty.

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44

Protopapas, Angelos L. „Stochastic hydrologic analysis of soil-crop-climate interactions“. Thesis, Massachusetts Institute of Technology, 1988. http://hdl.handle.net/1721.1/14676.

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45

Ganyani, Lloyd Munashe. „Evaluating summer cover crop species and management strategies for rainfed maize based cropping systems in the central region of the Eastern Cape Province of South Africa“. Thesis, University of Fort Hare, 2011. http://hdl.handle.net/10353/373.

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The overall objective of the whole study was to assess whether conservation agriculture (CA) systems can work in the Eastern Cape Province (EC). The CA systems were engaged through cover cropping to address land degradation problems by emphasizing high biomass production in order to realize short term benefits such as moisture conservation, weed suppression and soil fertility benefits under rainfed conditions in the central region of the Eastern Cape province. Since rainfall is the most limiting factor to crop production in the EC, a within season rainfall distribution analysis was conducted to expose the quality of the season (onset, end and duration) and hence the feasibility of CA systems to guide agronomic decisions by farmers in EC. To assess season parameters, thirty four years of daily rainfall was collected from the University of Fort Hare Research station and used to conduct the rainy pentad (5 day rainfall totals) analysis and the daily rainfall analysis using INSTAT software programme. Based on the pentad analysis, results showed that Alice does not have a rainy season in 1 out of 2 years (50% probability) but has one in 1 out of 4 years (25% probability level). This criterion proved to be harsher and conservative when compared to the daily rainfall approach which is more precise in measuring trends on season parameters. The daily rainfall analysis indicated a 65% feasibility for the dry land cropping systems in the EC. The pentad analysis however was effective in illustrating seasonality and it showed that the wet season begins on the 1st of November, ending on the 22nd of March lasting for 140 days. Though the season duration appeared too long, the existence of dry spells during critical growth stages adversely affects the quality of the season. The daily rainfall analysis also managed to derive a signal which can guide planting decisions. For planting to be successful, this analysis determined that 20 mm of rain should be received in two consecutive days after the 1st of November. A screening trial for cover crop biomass production and weed suppression was conducted on-station Fort Hare Research Farm (32°46' S and 26° 50' E), and Msobombvu village (MSBV) (32°44' S, and 26° 55' E) over two seasons (2007/08 and 2008/09). Six summer cover crops i.e. cowpea (Vigna unguiculata), dolichos lablab (Dolichos argenteus), sunnhemp (Crotalaria juncea), buckwheat (Fagopyrum sagittatum), forage sorghum (Sorghum bicolor) and sunflower (Helianthus annus) were evaluated for biomass yield, and weed suppression. Decomposition rates, moisture conservation and residual effects of these cover crops on the succeeding main crop were also evaluated under dryland conditions. The screening trial was laid in randomized complete block design replicated three times. Forage sorghum (Sorghum bicolor) and sunflower (Helianthus annus) were identified as high biomass producers and their dry matter yields ranged from 8 -12 t ha-1. These cover crops can be useful in generating high biomass in rainfed cropping systems in the EC. Other cover crops produced 3 - 4 t ha-1 of biomass which fell short of the 6 t ha-1 expected benchmark. However, these biomass yields were important in weed management since all cover crop species showed a similar degree of weed suppression which surpassed the weed fallow treatment. As dead mulches, the cover crops failed to show residual moisture conservation and weed control benefits for the succeeding maize crop mainly because of poor residue persistence, and low harvestable fallow rainfall. Buckwheat (Fagopyrum esculentum), was selected for further investigations in a follow up trial on station in 2008/09 season because of its weed smothering qualities, suitability to short cycle rotations, and possible allelopathic properties. The trial aimed at finding weed and cost effective management options of buckwheat that are none detrimental to the succeeding maize crop. Results showed that cropping systems where buckwheat is followed by a main crop may not work as they are unprofitable with respect to R100 rand invested. Though perceived to have allelopathic properties, buckwheat failed to demonstrate the possibilities of allelopathic action against weeds. Intercropping trial was conducted on-station in 2007/8-2008/09 seasons to try and find better ways of fitting legume cover crops into maize based cropping systems without compromising production of staple cereals on limited landholdings. The trials evaluated three factors in factorial combination, cover crop planting date, intercropping strategy, and cover crop species. The trial was laid as 2 x 2 x 3 factorial arranged in a split-split plot design. The main plot factor was cover crop planting date, cover crops simultaneously planted with maize and cover crop planted two weeks after planting maize (DKC 61-25). The sub-plot factor was intercropping strategy, strip intercropping and betweenrow intercropping. The sub-sub-plot factor was cover crop species, Dolichos lablab (Dolichos argenteus (Highworth), and Cowpea Vigna ungiculata (Agrinawa) plus control plots of sole maize. Results showed that same time planting of leguminous cover crops with maize using the in-between row intercropping patterns can derive appreciable system biomass (maize/cover crop) yields, utilize land efficiently whilst getting favourable maize grain yield. Based on the rainfall analysis, results showed that the probability of success when relay seeding cover crops after two weeks into standing maize is low (15% chances of success). This suggests that relay intercropping strategies would not work due to the unavailability of a good quality season.

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Osborne, Thomas Michael. „Towards an integrated approach to simulating crop-climate interactions“. Thesis, University of Reading, 2005. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.421206.

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47

Barrow, Elaine M. „On the construction and evaluation of scenarios of climate change for use in crop-climate models“. Thesis, University of East Anglia, 1999. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.297485.

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48

Groenewegen, Tracy. „Climate governance and the welfare state : a cross-national comparison“. Thesis, University of British Columbia, 2012. http://hdl.handle.net/2429/43084.

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This thesis explores the theoretical and empirical connection between the welfare state and national-level climate governance, drawing together the concepts of the ecological state, ecological modernization, and varieties of capitalism. It is argued that the eco-state represents the latest evolutionary phase of the modern state, though no state has achieved full eco-state status. In its nascence it has thus been layered on top of institutional structures that characterize earlier phases, namely welfare and production regimes. As a result, 'eco-state regimes' – differential degrees of eco-state development – have begun to take shape, mapping onto these two foundational regimes such that coordinated market economies with social democratic welfare states are the vanguards of ecological modernization, a discourse that dominates environmental policy arenas across the advanced capitalist world but that these particular countries have embraced with especial gusto and have the institutional and governance capacities to make a reality. It is proposed, then, that this ‘family of nations’ would exhibit comparatively strong climate governance from an ecological modernization perspective. Using available data, I assess the empirical relevance of this theoretical framework and suggest how it might be strengthened. A basic quantitative analysis of scores on the Climate Change Performance Index provides some support for the theory but the existence of two substantially discrepant cases – the United Kingdom and Finland – indicates that it is overly simplistic. I explore these two cases further in considerable depth using an interdisciplinary, comparative case study approach, which brings to light a range of influential extra-theoretical factors, including climatic, geographic, demographic, economic, political, historical, and geopolitical factors. My findings therefore highlight the importance of a broader conception of national context to a fuller understanding of variation in national-level climate governance and suggest an additional, alternative evolutionary path for countries with liberal market economies and liberal welfare states. However, the findings also call into question the possibility of a fully developed eco-state, and the likelihood of ecological modernization as a definitive solution to global climate change, in the context of globalized capitalism.

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Dodds, Paul Edward. „Development of a crop model to examine crop management and climate change in Senegal“. Thesis, University of Leeds, 2010. http://etheses.whiterose.ac.uk/1121/.

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Frequent droughts and sub-optimal crop management have been identified as the principal constraints on agricultural intensifcation in the Sahel. A new model, the Crop Model for Sahelian Adaptation Studies (CROMSAS), was developed to examine the influence of climatic variability, climate change and crop management strategies on millet yields. To improve the simulation of environmental stresses, several original features were implemented including a new leaf expansion methodology, semi-independent tillers, stress-dependent partitioning, and intercropping. CROMSAS was designed in a structured, accessible way to facilitate the use of the model by other researchers who want to examine climate change impacts in Africa. The influences of rainfall and crop management decisions over the period 1950{2009 were assessed for six locations in Senegal with average rainfall from 200mm to 1200 mm. Poor rainfall severely restricted yields in the north of the country in most years while having little impact in the more humid south. In the highly-populated groundnut basin, rainfall variability reduced the effectiveness and hence the profitability of fertiliser application. Current planting densities were found to lie within the optimal range but higher grain yields could have been produced, with lower risk of crop failure, by delaying planting by 2-3 weeks. The benefits of adapting crop management strategies according to the conditions in previous years were assessed. Using a fixed long-term strategy produced higher long-term yields and profits, at lower risk of crop failure, than frequently changing strategies. Projections from three GCMs for the period 2000-2100 were converted to daily weather data using a novel methodology and used to examine the impact of climate change on millet cultivation across Senegal. Grain yields were projected to be relatively unchanged for the SRES A2 and B1 scenarios, with losses due to temperature increases and higher vapour pressure deficits being balanced by CO2 fertilisation.

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50

Kocabas, Zahide. „Sensitivity of crop models to climate variations and modelling techniques“. Thesis, University of Nottingham, 1993. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.358287.

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Dissertationen zum Thema „Crops and climate“

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