Typescript (photocopy). / Digitized by Kansas Correctional Industries

In Lombok (Indonesia), annual cropping patterns in irrigated areas are divided into three cropping cycles of four months each. In better irrigation schemes, there are normally two irrigated flooded-rice crops, i.e. wet season and dry season lowland rice crops in sequence, followed by one non-rice crop cycle during the driest months (this is referred to as the twice-rice system). In less developed irrigation schemes, one lowland rice crop is normally grown during the rainy season, followed during the driest months by two cycles of non-rice crops, or a non-rice crop and a fallow (this is referred to as the once-rice system). In rainfed areas, especially in the vertisol soil areas, there are upland rice systems in the highland or hillsides, and “Gora” (dry seeded-flooded) rice systems in the lowland. In this area, rice is grown only once a year during the rainy season of the monsoon. Farmers in Lombok do not normally fertilise the non-rice crops such as soybean and mungbean grown following rice, and application rates of fertiliser to rice have fallen since the economic crisis in 1998. Therefore phosphorus (P) deficiency may be expected, which may explain the very low yields of soybean and mungbean achieved by farmers in Lombok. With low P, arbuscular mycorrhizas (AM) might be expected to play an important role in plant nutrition, but inoculation with arbuscular mycorrhizal fungi (AMF) increased root colonisation and yield of these crops in a recent field experiment in Lombok. There had been no survey of AMF populations in rice-based systems in Lombok prior to the work reported here, and little such work anywhere internationally. Therefore, an extensive survey was conducted in Lombok on the two main soil types with rice-based systems. Another field survey was conducted in the Riverina rice-growing area (Australia), as a comparative study to the Lombok survey. In Lombok, rice systems with longer total annual flooding duration had lower populations compared with upland or Gora rice systems. It was therefore suggested that the lower colonisation level in flooded rice was due to the flooded conditions, as well as soil chemical properties associated with flooded conditions, rather than the rice plant itself. There are options for improving AMF population for better growth of non-rice rotation crops, or even for rice crop in Lombok as fertilisers become less affordable and their use on flooded rice is declining. The easiest option is to inoculate AM fungi in the nursery or to make nursery beds in a paddock previously cropped with AMF-stimulating species, such as soybean, to start infection on rice seedlings, which should be better with a dry nursery. The second option is to modify the technique of growing rice, such as applying the SRI (System of Rice Intensification) principles, in which rice is grown without flooded conditions but intermittent short flooded and upland conditions. This will keep the soil in an aerobic condition much of the time and should facilitate the development of beneficial microbial populations and activities in the soil, such as AMF and nitrogen fixers. The SRI method has been reported to increase rice yield dramatically, even in soil with low fertility levels. / Doctor of Philosophy (PhD)

This thesis develops two related themes.The first is that participatory approaches to agricultural research and extension can provide a sound process for all stakeholders to learn how to develop more sustainable agriculture. The second is that appropriate levels of participation can be used to link knowledge from three important sources: local knowledge, scientific knowledge and experiential knowledge.The thesis develops these two related themes by examining the inconsistencies between esposed theories of participatory approaches (i.e.intended behaviour) and theories in action (i.e. what is actually practised).The study was based upon the work of a major research, development and extension (R, D and E)project known as the Western Farming Systems Project (WSFP),which was concerned with the development of sustainable rotations and cropping practices in south western Queensland and north western N.S.W. between 1994-1999. The study was conducted in the Balonne Shire, centred on the town of St. George, Queensland, Australia. / Master of Science (Hons)

Currently, online advertisements are created for specific dimensions and must be laboriously modified by advertisers to support different aspect ratios. In addition, publishers are constrained to design web pages to accommodate this limited set of sizes. As an alternative we present a framework for automatically generating visual banners at arbitrary sizes based on individual prototype ads. This technique can be used to create flexible visual ads that can be resized to accommodate various aspect ratios. In the proposed framework image and text data are stored separately. Resizing involves selecting a sub-region of the original image and updating text parameters (size and position). This problem is posed within an optimization framework that encourages solutions which maintain important structural properties of the original ad. The method can be applied to advertisements containing a wide variety of imagery and provides significantly more flexibility than existing solutions.

Currently, online advertisements are created for specific dimensions and must be laboriously modified by advertisers to support different aspect ratios. In addition, publishers are constrained to design web pages to accommodate this limited set of sizes. As an alternative we present a framework for automatically generating visual banners at arbitrary sizes based on individual prototype ads. This technique can be used to create flexible visual ads that can be resized to accommodate various aspect ratios. In the proposed framework image and text data are stored separately. Resizing involves selecting a sub-region of the original image and updating text parameters (size and position). This problem is posed within an optimization framework that encourages solutions which maintain important structural properties of the original ad. The method can be applied to advertisements containing a wide variety of imagery and provides significantly more flexibility than existing solutions.

System of Rice Intensification (SRI) has been introduced and practiced throughout Thailand. However, the conventional transplanting system is well-accepted among Thai farmers over the country. This paper quantifies and compares costs and benefits of SRI and the conventional system of rice cultivation in Thailand to find the best system for a farmer, the environment and a society. The scope of this paper includes a farmer’s profit, the environmental damages and a society’s net benefits categorized in clay soil and sandy loam conditions. The farmer’s profit consists of a production cost and income. The amount of fertilizer application, level of lethal dose and climate change cost are regarded as environmental damage components. The society has concerned over the farmer’s profit and the environmental cost in a decision. The study uses cost-benefit analysis to investigate mean and variation of profit and cost in monetary term. Monte Carlo simulation is utilized for quantifying risk in each scenario. The study finds that SRI saves the production input and increases yield gain significantly. The most impressive results are a reduction in water consumption and number of seeds. Also, the environmental damage caused by this system is lower due to less amount of chemical fertilizer and pesticide applications as well as a low rate of methane gas emission. Sensitivity analysis shows that SRI has better performance under best and worst case scenarios for both types of soil (clay soil and sandy loam). However, the system contains the highest risk of the farmer’s profit. In conclusion, SRI is more beneficial and efficient than conventional system. Still, risk aspects should be considered in decision making. This study can be employed as a framework for government or any parties, who are interested or have willingness to conduct a field study of SRI and the conventional rice cropping system or for the further study about the integrated system (a combination between SRI and conventional system).

The agroforestry practice of establishing shelterbelts and/or windbreaks composed of tree and shrub species that include buffaloberry (Shepherdia argentea Nutt.), caragana (Caragana arborescens Lam.) and sea buckthorn (Hippophae rhamnoides L.) is widespread within Saskatchewan. Shelterbelts play major roles in reducing wind speed, trapping snow, improving land-use efficiency and increasing economic returns. However, the practice of alley cropping within Saskatchewan is not popular. Also, apart from the protective roles the tree species offer in shelterbelts, some species have atmospheric nitrogen (N2)-fixation capabilities through biological nitrogen fixation (BNF) that are potentially important. The simultaneous integration of trees and crops on the same land management unit may lead to competition between crops and trees for growth resources such as nutrients, soil moisture and incoming radiation, the latter leading to limited access of light for understory crops. Understanding the contributions of the trees in supplying nitrogen (N) through BNF and in modifying microclimatic conditions in the alleyways would generate information needed to know their impacts on yield and nutrition of associated crops. In order to assess the contribution of the tree species in supplying N and minimizing interspecific competition while maximizing the benefits of tree-based intercropping systems, the thesis quantified the BNF capabilities of each species under greenhouse conditions using 15N dilution techniques and assessed how much of the fixed N2 is transferred to associated triticale (Triticale hexaploide Lart.) and oats (Avena sativa L.) under field conditions. Growth and yield of oats was also studied by measuring photosynthetically active radiation (PAR) and soil moisture in a Manitoba maple (Acer negundo var. negundo L.) -oats alley cropping system at Indian Head, SK. The BNF results showed that each of the test species fixes a substantial amount of N and there was a high transfer of N to associated triticale and oats. Results from the interspecific interaction study also showed that soil moisture was the primary factor affecting oats yields followed by light, with the south-lying oat plants affected more than north-lying. It can be concluded that alley cropping systems can be a practical and beneficial agroforestry practice within Saskatchewan. However, the distance between tree rows should be wide enough to permit farm machinery operations.

The major objective of this study was to determine whether or not food production per unit space can be increased by intercropping summer squash (Cucurbita pepo L.) with mung bean (Phaseolus aureus Roxb.) or pinto bean (Phaseolus vulgaris L.), and to identify the factors associated with growth and yield of summer squash, mung bean and pinto bean under intercropping regimes. A series of experiments were conducted during the period: Summer, 1977 to February, 1980, at both the University of Arizona, Experiment Station, Marana, and in a greenhouse at the University of Arizona, Campbell Avenue Farm. Intercropping mung beans or pinto beans with summer squash in either adjacent rows or within the row did not significantly influence the bean seed yield, although adjacent row intercropping tended to outyield the within row intercropping. Summer squash yield was more significantly reduced by within row intercropping than adjacent row intercropping. Root and shoot dry weights of container grown mung beans or pinto beans were significantly reduced by intercropping with summer squash, but summer squash root and shoot dry weights were not significantly affected. Intercropping summer squash with either mung beans or pinto beans was more beneficial at low nitrogen and phosphorus fertility levels than at higher levels. Summer squash fruit and shoot dry weights per unit space increased with increase in plant population, but they were not significantly influenced by intercropping with either mung beans or pinto beans. Intercropping high population summer squash with low population mung beans or pinto beans reduced both seed and biomass yields of the beans. However, increasing the bean plant populations had no influence on their seed and biomass yields. Harvest index of mung beans or pinto beans was neither influenced by intercropping with summer squash nor by increasing the bean plant population. Leaf area per unit space increased with increase in plant population, but intercropping had no significant influence in all cases. Specific leaf weight, leaf area-to-leaf weight ratio, and leaf weight ratio were neither influenced by intercropping nor by varying the plant populations. Mung bean seed yield was significantly to highly significantly correlated with harvest index and biomass, but highly negatively correlated with leaf area index, while pinto bean seed yield was very highly correlated with biomass and harvest index. Summer squash fruit yield was significantly to highly significantly correlated with shoot dry weight, leaf area, leaf area index and specific leaf weight. Accumulations of nitrate nitrogen and/or phosphorus in the leaf petioles of mung beans, pinto beans or summer squash were neither influenced by intercropping nor by increasing the nitrogen or phosphorus fertility levels. The economic yields of field grown mung beans, pinto beans or summer squash were not significantly correlated with petiole accumulations of nitrate nitrogen and phosphorus. While summer squash exhibited autotoxicity, mung bean root leachates tended to promote growth of pinto beans and summer squash. Food production per unit space was increased by as much as 76% by intercropping summer squash with pinto beans, while intercropping summer squash with mung beans increased food production by 63%. Under certain plant combinations, dry matter yield per unit space was increased by as much as 185% by intercropping summer squash with mung beans, while intercropping summer squash with pinto beans increased the dry weight yield by as much as 81%.

This item was digitized as part of the Million Books Project led by Carnegie Mellon University and supported by grants from the National Science Foundation (NSF). Cornell University coordinated the participation of land-grant and agricultural libraries in providing historical agricultural information for the digitization project; the University of Arizona Libraries, the College of Agriculture and Life Sciences, and the Office of Arid Lands Studies collaborated in the selection and provision of material for the digitization project.

In consideration of the chronic poverty of farmers in Rwanda as well as in other developing countries where self-sufficient agriculture is practiced, this study examines what the well studied theory of specialization and trade, if implemented, could bring to Rwandan farmers in terms of production and profits. / To attain this objective, a spatial optimization model with linear programming was built and used to maximize the potential production and net returns which were compared to those from the traditional system. The model was built in a way that it also shows the pattern of trade and quantities traded. / The results show that a regional specialization system would allow, on the national level, more production, higher net returns, and more trade than the traditional system (self-sufficient agriculture) as expected according to the theory of specialization and trade. Nevertheless, the net return in some regions decreases in the new system, which necessitates a compensation plan for those regions. / However, it has to be noted that despite these gains, the adoption of the new plans requires a consideration of many other factors that are not covered in this study. Of those factors, the most obvious are the need to improve the transportation and marketing infrastructure, changing farmers' attitudes and objectives towards commercial agriculture, and securing equity, security, and sustainability in the system.