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.

Irrigation in 1980 accounted for approximately 52 per cent of the water consumed in Southern Africa. The need for planning water resources in the agricultural sector is therefore apparent. Much of Southern Africa's arable farming is carried out on land which, in terms of soil moisture availability to crops, can be described as marginal. Information on soil moisture is therefore valuable to the agriculturalist for planning irrigation schemes and for dryland farming. The objectives of this study were to provide the information mentioned above. This was achieved by producing a detailed delimitation of 712 zones throughout Southern Africa, of more or less homogeneous climate and by providing estimates of crop water requirements under dryland and irrigated conditions in each zone. At the same time the bulk of information which is normally forthcoming from such an analysis involving a large number of combinations of possible input, i.e. crops, soils and planting dates, was reduced, whilst the essential information content was retained. The study provided inter alia an estimate of the frequency of non-exceedance of certain levels of irrigation requirement, based on analyses of soil moisture budgets using long daily rainfall records. The soil moisture budgeting models which were used to estimate the above information were verified inter alia using field measurements of soil moisture. The irrigation analysis was designed such that the results should not became redundant when the inevitable improvement occurs in the estimation of crop factors or soil moisture variables nor if the farming practices change with respect to planting dates. A dryland soil moisture budget analysis for a range of crops and soils was performed in addition to the abovementioned irrigation analysis. The need for this latter study stemmed from the belief that irrigation should not be considered in isolation but rather as one of a range of options, many of them involving dryland farming, facing the agriculturalist. In addition to the dissertation, this study produced a map of Southern Africa on which the 712 homogeneous climate zones are depicted. For each of these zones four pages of computer printout were produced. These pages contain the results of the crop water requirements study for irrigated conditions and the crop water requirement deficit, runoff and an index of stress days for a range of crops, soils and planting dates, under dryland conditions. / Thesis (Ph.D.)-University of Natal, Pietermaritzburg, 1988.

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.

As the debate on the impacts of global climate change goes on at global and regional scale, climate change impacts are already being felt at local level. The thesis aims at exploring climate change as a driver of environmental and smallholder farmers’ livelihood vulnerability in Makonde District of Zimbabwe. Specifically the study seeks to: determine climate change trends and manifestations; evaluate household-level impacts of climate change and associated environmental changes on smallholder farmers’ livelihoods and lastly; to investigate the extent of household-level coping and adaptation strategies to climate change in the Makonde rural community in Zimbabwe, especially farmers in Makonde Communal Lands. Given the fact that the subject under study is multidimensional in scope, a mix of research methods was adopted in this case study. Whilst it is largely qualitative in design, the study involved some quantitative data and thus, a triangulation of different data sources and data gathering instruments was employed. The instruments used include; key informant interviews, structured observations and a household questionnaire survey. The analysis was based on a final sample of 434 out of the originally anticipated 500 households. In addition to the households’ sample, were twenty key informants and transect walk observations. The qualitative data was analyzed by means of coding, memoing, descriptions, typologies, taxonomies and visual representations, whilst quantitative data was processed through the Statistical Package for Social Sciences (SPSS) and complimented by Microsoft Excel to generate various forms of descriptive statistics. The findings suggest that climate change in the Makonde Rural District that includes the Makonde Communal Lands has been significant during the past thirty years. The climate change has contributed to significant local environmental stresses affecting local resources such as forests, fauna, water, pastures and soil among other natural assets. The local livelihoods show high levels of vulnerability to climate change due to notable low adaptive capacity. The high level of vulnerability to changing climate is exposing the study population to increased prevalence of: poverty, crop and livestock failures, food insecurity, malnutrition, disease and rural urban migration among other impacts. The study concludes that the factors creating barriers to climate change adaptation are related those contributing to poverty and holding back sustainable local development. Among the key suggestions to enhance the community’s climate change adaptation capacity, the thesis presents an establishment of a government-driven, multi-dimensional and multi-stakeholder intervention mechanism to help local communities manage their vulnerability. / Environmental Sciences / D. Litt. et Phil. (Environmental Management)

No description available.

Weenen Nature Reserve (WNR) has a long history of unwise land use that resulted in severe overgrazing and soil degradation. Since 1948 several soil conservation and reclamation programs have been undertaken to halt the degradation process and regain the agricultural potential of the area. This study evaluates the current agricultural potential of the reserve under rainfed cultivation primarily based on climatic, soil, topographic and crop requirement data collected from different sources. Spatial information on each of the land resources parameters was digitally encoded in a GIS database to create thematic layers of the land resources. Crop requirement information on seven different crops that were selected as representative crops under rainfed agriculture in the area namely, maize, Sorg):mm, cotton, dry bean, soya bean, potato and cabbage was compared with the land resources parameters. The thematic layers of the land resources were then overlyed using a GIS to select areas that satisfy the crop requirements. The results showed that WNR has two major limitations in relation to its use for rainfed agriculture, namely its shallow and rocky soils and its arid climate. Consequently, the resulting land suitability maps indicate that WNR has very low suitability for all of the crops considered. Dry beans are relatively well adapted to the area followed by sorghum. Maize and soya beans are preferred over cotton. Potatoes'and cabbages are least adapted to the area because of the high temperatures during thCl/growing season. It was concluded that generally the reserve is not suitable for rainfed agriculture. However, there is a small area of land in the northern part of the reserve that can be cultivated. The rugged area in the central part of the reserve can be used for grazing with careful managemeIit. The eastern and southern parts can only be used as habitats for wildlife owing to their steep topography and inaccessibility, whereas the highly degraded areas in the western parts of the reserve should be kept under soil conservation and reclamation. / Thesis (M.Sc.)-University of Natal, Pietermaritzburg, 2003.

This thesis presents results from two separate studies. First, the impact of bearer length on yield components within the canopy was investigated in season 2005/06, on a commercially-managed, mechanically-pruned vineyard of Vitis vinifera L. Cabernet Sauvignon in Coonawarra, South Australia. Pruning resulted in the retention of bearers with 1-7 nodes, with the weighted average bearer length being two nodes for the canopy. As bearers of one to five nodes in length were the most common, these were studied. Yield components (on a per shoot basis) were analysed according to the node position on the bearer at which the shoot arose. Both budburst and inflorescence number per node were highest at the distal node positions on each length bearer, even if the nodes were at the same positions from the base of the bearer and would normally be expected to have similar fertility. Budburst appeared to act by modifying inflorescence number per node based on the relative location of each node from the apex of the bearer. Shoots that arose from the most distal node positions had the highest flower number per inflorescence and berry number per bunch. Flower number per inflorescence was significantly higher on two-inflorescence shoots than single-inflorescence shoots. The relationship between bunch size and node position, unlike that between inflorescence number and node position, was dependent on bearer length. The relative size of the inflorescence appeared to be affected more so by the node pOSition at which the shoot occurred on the bearer, as opposed to the actual node position on the shoot at which the inflorescence occurred. There was a positive, non-linear relationship between average fruit yield per bearer and bearer length. Although yield was highest from the bearer with the highest node number (five nodes), there was no significant difference in yield per bearer for the bearers of three to five nodes in length. If average bearer length was increased from two to three nodes, the potential yield gain per bearer is estimated at 38 per cent. The second study presents results of correlations between bunch number and components of bunch weight (flower number and berry number) to investigate co-development of bunch number and bunch size. These data were collected from 4 vineyards in the Limestone Coast Zone of South Australia from Vilis vinifera L. Chardonnay, Shiraz and Cabemet Sauvignon during seasons 2002/03 to 2006/07. The significant correlations found between fertility and both bunch weight and flower number per inflorescence suggest that the same factors that affect bunch number in a particular season will also affect bunch size. When inflorescence primordia were initiated and differentiated under cool conditions, actual bunches per node and flowers per inflorescence were low. Differences in climate between the vineyard sites were found to be minimal and therefore did not strongly affect the magnitude of the yield components at the vineyard sites. Cultural practices at each vineyard site were sufficiently variable to affect fertility levels. Genotype is thought to determine the range of flowers per inflorescence that a variety can potentially carry, whereas actual flower number per inflorescence is thought to be determined by inflorescence primordium initiation and differentiation temperatures, as well as temperatures during budburst. Despite significant correlations between flower number per inflorescence and berry number per bunch, flower number per inflorescence preflowering for Cabemet Sauvignon, Shiraz and Chardonnay is inversely related to actual percentage fruit set. This is possibly a survival mechanism for the grapevine as it allows the vine to maximise yield each season without detriment to its longevity. Bunches per vine accounted for the majority of the seasonal variation in yield per vine. Fluctuations in bunch number per vine (and therefore yield) are likely to be reduced by varying the number of nodes retained per vine according to the relative fruitfulness per node present pre-pruning. This practice is therefore likely to result in the seasonal variation of berries per bunch becoming a stronger driver of yield. The commercial impacts of these studies are two-fold. Data presented will assist growers to understand the reasons for which their pruning regimes are affecting yield production and how these pruning regimes may be modified to achieve a target yield-particularly when growers are faced with seasons of low predicted fertility. In addition, data presented will allow growers to improve their crop forecasting accuracy, with a greater understanding of the link between bunch number and bunch size. In the current situation of oversupply in the wine industry, wineries are adopting a tough stance towards growers over-delivering on their grape contracts. Therefore, any assistance that can be provided to growers on improving accuracy of yield estimates will be beneficial both to the grower and winery. / http://proxy.library.adelaide.edu.au/login?url= http://library.adelaide.edu.au/cgi-bin/Pwebrecon.cgi?BBID=1352744 / Thesis (M.Ag.Sc.) -- University of Adelaide, School of Agriculture, Food and Wine, 2009

This thesis presents results from two separate studies. First, the impact of bearer length on yield components within the canopy was investigated in season 2005/06, on a commercially-managed, mechanically-pruned vineyard of Vitis vinifera L. Cabernet Sauvignon in Coonawarra, South Australia. Pruning resulted in the retention of bearers with 1-7 nodes, with the weighted average bearer length being two nodes for the canopy. As bearers of one to five nodes in length were the most common, these were studied. Yield components (on a per shoot basis) were analysed according to the node position on the bearer at which the shoot arose. Both budburst and inflorescence number per node were highest at the distal node positions on each length bearer, even if the nodes were at the same positions from the base of the bearer and would normally be expected to have similar fertility. Budburst appeared to act by modifying inflorescence number per node based on the relative location of each node from the apex of the bearer. Shoots that arose from the most distal node positions had the highest flower number per inflorescence and berry number per bunch. Flower number per inflorescence was significantly higher on two-inflorescence shoots than single-inflorescence shoots. The relationship between bunch size and node position, unlike that between inflorescence number and node position, was dependent on bearer length. The relative size of the inflorescence appeared to be affected more so by the node pOSition at which the shoot occurred on the bearer, as opposed to the actual node position on the shoot at which the inflorescence occurred. There was a positive, non-linear relationship between average fruit yield per bearer and bearer length. Although yield was highest from the bearer with the highest node number (five nodes), there was no significant difference in yield per bearer for the bearers of three to five nodes in length. If average bearer length was increased from two to three nodes, the potential yield gain per bearer is estimated at 38 per cent. The second study presents results of correlations between bunch number and components of bunch weight (flower number and berry number) to investigate co-development of bunch number and bunch size. These data were collected from 4 vineyards in the Limestone Coast Zone of South Australia from Vilis vinifera L. Chardonnay, Shiraz and Cabemet Sauvignon during seasons 2002/03 to 2006/07. The significant correlations found between fertility and both bunch weight and flower number per inflorescence suggest that the same factors that affect bunch number in a particular season will also affect bunch size. When inflorescence primordia were initiated and differentiated under cool conditions, actual bunches per node and flowers per inflorescence were low. Differences in climate between the vineyard sites were found to be minimal and therefore did not strongly affect the magnitude of the yield components at the vineyard sites. Cultural practices at each vineyard site were sufficiently variable to affect fertility levels. Genotype is thought to determine the range of flowers per inflorescence that a variety can potentially carry, whereas actual flower number per inflorescence is thought to be determined by inflorescence primordium initiation and differentiation temperatures, as well as temperatures during budburst. Despite significant correlations between flower number per inflorescence and berry number per bunch, flower number per inflorescence preflowering for Cabemet Sauvignon, Shiraz and Chardonnay is inversely related to actual percentage fruit set. This is possibly a survival mechanism for the grapevine as it allows the vine to maximise yield each season without detriment to its longevity. Bunches per vine accounted for the majority of the seasonal variation in yield per vine. Fluctuations in bunch number per vine (and therefore yield) are likely to be reduced by varying the number of nodes retained per vine according to the relative fruitfulness per node present pre-pruning. This practice is therefore likely to result in the seasonal variation of berries per bunch becoming a stronger driver of yield. The commercial impacts of these studies are two-fold. Data presented will assist growers to understand the reasons for which their pruning regimes are affecting yield production and how these pruning regimes may be modified to achieve a target yield-particularly when growers are faced with seasons of low predicted fertility. In addition, data presented will allow growers to improve their crop forecasting accuracy, with a greater understanding of the link between bunch number and bunch size. In the current situation of oversupply in the wine industry, wineries are adopting a tough stance towards growers over-delivering on their grape contracts. Therefore, any assistance that can be provided to growers on improving accuracy of yield estimates will be beneficial both to the grower and winery. / http://proxy.library.adelaide.edu.au/login?url= http://library.adelaide.edu.au/cgi-bin/Pwebrecon.cgi?BBID=1352744 / Thesis (M.Ag.Sc.) -- University of Adelaide, School of Agriculture, Food and Wine, 2009

This thesis presents results from two separate studies. First, the impact of bearer length on yield components within the canopy was investigated in season 2005/06, on a commercially-managed, mechanically-pruned vineyard of Vitis vinifera L. Cabernet Sauvignon in Coonawarra, South Australia. Pruning resulted in the retention of bearers with 1-7 nodes, with the weighted average bearer length being two nodes for the canopy. As bearers of one to five nodes in length were the most common, these were studied. Yield components (on a per shoot basis) were analysed according to the node position on the bearer at which the shoot arose. Both budburst and inflorescence number per node were highest at the distal node positions on each length bearer, even if the nodes were at the same positions from the base of the bearer and would normally be expected to have similar fertility. Budburst appeared to act by modifying inflorescence number per node based on the relative location of each node from the apex of the bearer. Shoots that arose from the most distal node positions had the highest flower number per inflorescence and berry number per bunch. Flower number per inflorescence was significantly higher on two-inflorescence shoots than single-inflorescence shoots. The relationship between bunch size and node position, unlike that between inflorescence number and node position, was dependent on bearer length. The relative size of the inflorescence appeared to be affected more so by the node pOSition at which the shoot occurred on the bearer, as opposed to the actual node position on the shoot at which the inflorescence occurred. There was a positive, non-linear relationship between average fruit yield per bearer and bearer length. Although yield was highest from the bearer with the highest node number (five nodes), there was no significant difference in yield per bearer for the bearers of three to five nodes in length. If average bearer length was increased from two to three nodes, the potential yield gain per bearer is estimated at 38 per cent. The second study presents results of correlations between bunch number and components of bunch weight (flower number and berry number) to investigate co-development of bunch number and bunch size. These data were collected from 4 vineyards in the Limestone Coast Zone of South Australia from Vilis vinifera L. Chardonnay, Shiraz and Cabemet Sauvignon during seasons 2002/03 to 2006/07. The significant correlations found between fertility and both bunch weight and flower number per inflorescence suggest that the same factors that affect bunch number in a particular season will also affect bunch size. When inflorescence primordia were initiated and differentiated under cool conditions, actual bunches per node and flowers per inflorescence were low. Differences in climate between the vineyard sites were found to be minimal and therefore did not strongly affect the magnitude of the yield components at the vineyard sites. Cultural practices at each vineyard site were sufficiently variable to affect fertility levels. Genotype is thought to determine the range of flowers per inflorescence that a variety can potentially carry, whereas actual flower number per inflorescence is thought to be determined by inflorescence primordium initiation and differentiation temperatures, as well as temperatures during budburst. Despite significant correlations between flower number per inflorescence and berry number per bunch, flower number per inflorescence preflowering for Cabemet Sauvignon, Shiraz and Chardonnay is inversely related to actual percentage fruit set. This is possibly a survival mechanism for the grapevine as it allows the vine to maximise yield each season without detriment to its longevity. Bunches per vine accounted for the majority of the seasonal variation in yield per vine. Fluctuations in bunch number per vine (and therefore yield) are likely to be reduced by varying the number of nodes retained per vine according to the relative fruitfulness per node present pre-pruning. This practice is therefore likely to result in the seasonal variation of berries per bunch becoming a stronger driver of yield. The commercial impacts of these studies are two-fold. Data presented will assist growers to understand the reasons for which their pruning regimes are affecting yield production and how these pruning regimes may be modified to achieve a target yield-particularly when growers are faced with seasons of low predicted fertility. In addition, data presented will allow growers to improve their crop forecasting accuracy, with a greater understanding of the link between bunch number and bunch size. In the current situation of oversupply in the wine industry, wineries are adopting a tough stance towards growers over-delivering on their grape contracts. Therefore, any assistance that can be provided to growers on improving accuracy of yield estimates will be beneficial both to the grower and winery. / http://proxy.library.adelaide.edu.au/login?url= http://library.adelaide.edu.au/cgi-bin/Pwebrecon.cgi?BBID=1352744 / Thesis (M.Ag.Sc.) -- University of Adelaide, School of Agriculture, Food and Wine, 2009

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.