No description available.

No description available.

Grain corn (Zea mays L.) production occupies more farmland than any other annual crop in Quebec and is expanding demand from the livestock sector and the emerging bioethanol industry. Corn production requires high nutrient inputs and intensive tillage (IT). Many producers have thus switched to conservation tillage systems like ridge-tillage (RT) to overcome soil compaction and erosion problems that are common in IT systems. However, fertilizer guidelines developed for IT soils are used in RT although RT adoption greatly modifies phosphorus (P) dynamics. Lower fertilizer P requirements are expected because arbuscular mycorrhizal (AM) symbiosis known to enhance plant P nutrition are minimally disrupted under RT, compared to IT systems. A two-year study was conducted on a commercial farm in the Monteregie region (Quebec, Canada) to investigate the effects of P fertilizer rates and soil P-saturation status on corn early growth, nutrition and yield. Surface soil plant-available P was monitored in situ with anionic exchange membranes (P AEM) from seeding to the end of July. The effects of indigenous AM fungi on corn parameters and rhizosphere soil P pools were also investigated in untreated (AMNI) or AM-inhibited fungicide-treated (AMI) soils. Quebec's P fertilizer guidelines underestimated the soil P fertility in studied soils. Adding inorganic P (Pi) did not improve the early corn P nutrition, growth or yield, and had little impact soil PAEM. Variations in PAEM were better explained by climatic variables. AMNI corn had similar early development and high yield, regardless of whether P fertilizer was applied, whereas AMI plants needed P fertilizer to produce optimal yield. AMNI corn had reduced dependence on Pi inputs due to more efficient uptake of soil solution P i in surface and rhizosphere soils during the first 22 days after seeding (DAS), In the rhizosphere, available-Pi pool appeared to be used first to replenish the resin-P pool, but over the longer term, AM symbiosis also enhanced NaHCO3-Po mobilization through a mechanism that remains unclear. Deeper understanding of the mechanisms by which AM fungi alter soil P dynamics will contribute to the development of more sustainable P fertilizer programs for RT systems.

Note: / Nature has used shrubbery in the glades of her woods, along the edges of her waterways, softening the angles, changing them into graceful curves. This shows us that if we are to have beautiful surroundings we must copy nature, and use shrubs liberally around our homes, in our public parks and plaqygrounds. [...]

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Cereal aphids started to infest cereals in the first week of June and reached their peak in the second and third week of July. They could affect both the quantity and quality of grain yields, but I recommend chemical control only when the aphid population reaches the economic threshold level, which was calculated as 16 aphids/tiller. Pirimicarb is recommended for chemical control, as it controlled aphids efficiently and had a minimal effect on the available predators and parasites. A sequential sampling plan has been developed to detect if populations reach economic threshold. Temperature accumulation, starting from the first detection of aphids on the crop, allowed prediction of the time of peak population on the crop.

No description available.

The relationship of musicmaking to the city is a complicated one as it often takes very specific and complex spatial and social forms. The example of Montreal can be used to illustrate some of the ways in which these forms manifest themselves. By considering the way in which two particular cultural spaces, namely scene and bohemia, emerge in relation to musical activity, this project analyzes the nature of musicmaking and its role in shaping a unique experience of the city. It frames a case study of Montreal musicmaking to explore the ways in which scenes and bohemias are connected to city life. It also considers the way in which a particular image of the city manifests itself through musicmaking. The collective representation of Montreal as a bohemia by anglophone musicmakers works with and through a number of social divisions and cultural distinctions. It is argued that the nature of place-images and mythology in musicmaking is such that they have a profound effect on the sociomusical experience of the city. Montreal is privileged by many anglophone musicmakers as an ideal city in which to be culturally active, as the city's weak economic state is perceived to foster the conditions best suited to a flourishing bohemia. This project examines the relationship of musicmakers to Montreal, using a variety of research methods and theories. Cognitive mapping, diaristic accounts and interviews are utilized to better apprehend how a chosen image of Montreal affects musical practice. The socioeconomic history of Montreal in the latter half of the twentieth century is used to frame an analysis of the emergence of an independent music scene in the city. By exploring a number of relevant factors, this project documents the ways in which musicmaking is structured in relation to the economic, political and social dimensions of Montreal.

Increasing levels of nitrate (NO3-) in groundwater have become a major environmental and health concern. In situations where NO3-concentrations in the soil-water system pose an environmental hazard, water table management may be a desirable practice to reduce such pollution. Careful management of N applications is also believed to reduce NO3- levels. / A field experiment was conducted in 1996 and 1997 at St. Emmanuel, Quebec, about 30 km South-West of Macdonald Campus of McGill University, to investigate the effect of water table management (WTM) and N fertilizer combinations on potentially leachable NO3- and denitrification rates in the top soil layer (0--0.15 m). The field was planted with monocrop corn (Zea mays. L) in both years. Treatments consisted of a factorial combination of two water table managements, free drainage (FD) and subirrigation (SI) (about 1.0 m and 0.6 m, respectively, below the soil surface) and two N fertilizer rates, 200 kg ha-1 (N200) and 120 kg ha-1 (N120). / Water table management had a significant effect on reducing NO3 - concentrations in the soil profile. Subirrigation treatment reduced NO3- in the top soil layer by 41% and 15% in 1996 and 1997, respectively. Similarly, NO3 - levels were 50% and 20% lower in N120 compared to N200 treatment. / Climatic conditions (rainfall and temperature) played a large role in regulating denitrification rates. Due to drier and cooler conditions in 1997, denitrification rates were lower compared to 1996, leaving more NO3 - in the soil profile. Following harvest, this high NO 3- concentration may be subject to leaching.

This qualitatively-oriented thesis explores, describes, and interprets the emergence of Quebec's environmental movement, placing it in its proper historical and socio-political setting. The environmental movement was one of the myriad of new social movements that arose in the 1960s and '70's in western nations. Although it transcended national boundaries, development of environmental movements in Europe and North America differed, just as they did at more regional levels, depending on cultural distinctions, the structures of opportunity, and the amount of available resources, among other things. With its Quiet Revolution, Quebec society gained a new pluralism, secularism, and liberalism that gave the rising middle class and the large proportion of educated youth a greater say in decisions and fostered the development of public interest groups, such as environmental groups. These were aided by government grants that became available after the October Crisis in 1970. Between 1970 and 1980, environmentalism in Quebec became a legitimate societal concern as various associations and individuals began working separately and together on urban air and water pollution problems, recycling projects, and transportation and energy issues, among others. The impetus to act on behalf of the province's environment was due in part to the severity and distribution of pollution problems and to the moral and ideological convictions of group leaders and core members of environmental groups. Informal social and communication networks, such as the counterculture, the antinuclear movement, and health-food coops provided the burgeoning environmental movement with ideologies, members, and solidarity. Unlike its parallel in the United States, Quebec's movement had few historical or ideological links with efforts to preserve wilderness and it developed social- rather than nature-protection principles. (Abstract shortened by UMI.)