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.

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.

Academisch proefschrift--Vrije Universiteit te Amsterdam, 1998. / "Code 923, NASA GSFC Biospheric Sciences Branch"--Cover. "April 1998." "GSFC/CR-1998-206852." "Contract NAS-31752." Includes bibliographical references (p. 81-90).

Thesis (M.Sc. (Natural Resources Management))--Mahidol University, 2005.

Thesis (Ph.D.(Environmental Economics))--University of Pretoria, 2009. / Abstract in English. Includes bibliographical references.

Academisch proefschrift--Vrije Universiteit te Amsterdam, 1998. / "Code 923, NASA GSFC Biospheric Sciences Branch"--Cover. "April 1998." "GSFC/CR-1998-206852." "Contract NAS-31752." Includes bibliographical references (p. 81-90).

Thesis (M. A. (Sociology)) -- University of Limpopo, 2017 / The study explored Mutoko community members’ perceptions of climate change and its impact on subsistence farming. Mutoko is a rural community situated in the eastern part of Zimbabwe. Focus group discussions were conducted to explore perceptions of climate change and its impacts on subsistence farming. The study findings show that the primary source of food is subsistence farming. The main crop grown in Mutoko is maize, followed by ground nuts (peanuts), and indigenous vegetables. Maize, ground nuts, sunflowers (for seed), sorghum and millet are grown for household consumption. The study reports community members’ perceptions and views of changes in the local natural environment. The changes are increased temperature and scarcity of rain. Observable impacts of these changes are decreased crop yields in times of drought. The findings are supported by observation that Zimbabwe lies in a semi-arid region with limited and unreliable rainfall patterns and temperature variations. Rainfall exhibits considerable spatial and temporal variability. Generally, the impact of climate change on subsistence farming was the major concern among the participants. Though the study was not aimed at documenting adaptation measures taken to lessen the negative impacts of increased temperature and rainfall scarcity on crop production, the study shows that adaptive measures have been developed and used to adapt and cope with climate change. Community members are adapting to the impacts of increased temperature and scarcity of rain through their culturally informed mechanisms. The mechanisms include change of crops, use of manure to improve soil structure and mulching. It is concluded that the impact of climate change on subsistence farming is real and is negatively affecting food security in the study area. Farmers gave different views on the following; knowledge about climate variations, changes in environmental conditions, changes in temperature patterns and changes in rainfall patterns. / Centre of Indigenous Knowledge Systems (CIKS) and National Research Foundation (NRF)

No description available.

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.

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