Research

Research is evaluating hybrid poplar varieties, as well as Red Pine, Scots Pine and Siberian Larch, in order to determine which trees are best suited for the wide range of soils and growing conditions in Saskatchewan. Evaluation of nutrient cycling budgets and a variety of cultural factors such as weed management and soil nutrient amendments will determine how poplar plantations can be managed most efficiently without having a deleterious effect on soils. Other projects are examining the effects of acid rain and soil acidification by comparing tree growth patterns in areas that have different rates of exposure to acid rain. The potential benefits associated with acid rain such as the increased delivery air-borne calcium, a nutrient that is essential to healthy tree growth, is also being studied. Harvesting methods are also being examined to determine how different tree removal methods can impact forest soil health. Recent studies have also expanded into the area of bio fuels and the use of hybrid species such as willow to produce an economical, renewable fuel source.

The goal of applied pedology research is to improve our fundamental understanding of pedologic properties of Canadian ecosystems relative to land use and climate change. Detailed consideration of the ecosystem and management variables that influence carbon and nitrogen cycling processes will improve our understanding of what governs the availability of these nutrients for agriculture and for greenhouse gas emissions. Techniques involve a combination of field measurements and analytical methods, including quantitative stable isotope techniques (13C and 15N). Using Geographic Information Systems (GIS) technology, the process information can be integrated with our expanding knowledge of landscape-scale relationships and the extensive regional soil survey information available from the Soil Landscapes of Canada database. This multi-scale approach will facilitate land use planning and environmental monitoring applications.

This research group applies a variety of molecular-scale spectroscopic tools to study reactions that occur in natural systems. This research program is elucidating reactions that determine the fate and toxicity of metals and metalloids in natural systems. Studies currently span environments as diverse as New Zealand hot springs and Arctic lakes. One of our major analytical tools is the Canadian Light Source. Synchrotron radiation is used to: determine phosphate speciation in bio solids, animal manures and soils; discover selenite and selenate bonding mechanisms on a range of mineral surfaces; and evaluate the utility of extremophilic microorganisms in trace metal removal from industrial effluents.

Research is assessing gas emissions from soils in order to develop land management and resource management systems that are environmentally sustainable. Just as nitrogen and other chemical elements can play beneficial roles in maintaining healthy soils and supporting plant life, they can also contribute to environment degradation under certain conditions. For example, the transformation of soil-borne nitrogen into nitrous oxide gas has been identified as key factor in global warming, desertification and other significant climatic trends. Similarly, emissions of methane and carbon dioxide gas, caused by a variety of human activities such as fossil fuel consumption, deforestation and intensive agricultural production, are having a deleterious effect on sensitive ecosystems around the world. Another area of research is examining soil carbon content and carbon cycling in prairie soils to determine how carbon sequestration is influenced by plant cover, topography and other environmental variables. This work could lead to the development of scientific models that more accurately reflect greenhouse gas emissions in Western Canada.

Field studies have been established to evaluate animal manure as a source of fertilizer for commercial crop production. Factors such as application rates, timing and methods of application have been evaluated to determine how these variables affect soil physical properties, nutrient loading, microbial populations and overall soil quality. Data taken from the field trials is being used to develop improved manure management guidelines for the province's intensive livestock industry. Also, by studying the way water moves over and through the soil, researchers are ensuring that manure management practices are environmentally sustainable and do not threaten the quality of surface or groundwater reserves. For example, fluorescent dye tracing techniques are being used to monitor the speed at which potentially fatal E. coli bacteria can move through different soil types and enter groundwater systems. Research is also detailing hydrological flow mechanisms and soil characteristics that allow micro-organisms to penetrate some soils, but not others.

Researcher is examining these relationships and assessing their consequences close to home and in remote locations such as Devon Island in Canada's Far North. Ecotoxicological studies at the department are hoping to find answers to some critical questions. For example, what are the molecular biology controls that affect mercury, arsenic, nitrogen and sulfur cycles in extreme environments? Can human activity be corrected or modified in an effort to protect the environment? And can biogeochemical activities be regulated to ensure that sensitive ecosystems and the life forms they support remain healthy? Specific research projects within this area include assessments of atmospheric mercury, its migration to Canada's High Arctic and the factors involved in its transformation to methyl mercury, a form that is highly bio available and ultimately responsible for increasing toxicity levels in the Arctic food chain. Other studies seek to explain how arsenic is mobilized in non-aqueous environments, research whose importance will become increasing evident as the demands on limited fresh water resources continue to grow. Further research has documented how the presence of certain soil constituents can influence the bio availability of soil-borne contaminants, introducing otherwise stable toxic elements into the food chain.

This area of research covers a broad range of issues associated with nitrogen transformations and nitrogen cycling in an effort to understand how we can manage and the nutrient more efficiently. Investigations of the process of nitrogen mineralization, a key process in which nitrogen contained in soil organic matter is transformed into inorganic nitrogen, will help optimize nitrogen availability for crop production and reduce nitrogen losses to the environment. Synchrotron studies at the Canadian Light Source are providing new information regarding the structure of organic nitrogen compounds that ultimately will help us understand the controls on nitrogen cycling processes. Studies examining nitrogen fixation by leguminous crop will advance our understanding of how atmospheric nitrogen can be harnessed and used for optimal benefit. To this end, the identification, isolation and commercial development of beneficial soil micro-organisms such as rhizobia bacteria and other plant-growth promoting microbes has been instrumental in the expansion of the prairie pulse crop industry. Related agronomic research is taking a closer look at the delicate but critical interactions between rhizobia and host plants to determine how soil-borne toxins, hydrocarbons and pollutants such as herbicide residues, can interfere with the nitrogen fixing process and cause costly losses in crop production.

Research is focused on nutrient management in organic farming systems. Crop rotations, green manures and organic ammendments are investigated for their role in maintaining and/or supplying nutrients. Topics include optimizing the role of legume crops in organic rotations, soil phosphorous management, and quantifying the role of soil biology in organic soil fertility. Research in this area is also focused on evaluating the sustainability of practices normally associated with organic agriculture, but that have the greatest applicability for conventional agriculture.

Phytoremediation studies examine the symbiotic relationships between plants and soil-based micro-organisms that facilitate the removal of harmful contaminants such as petroleum hydrocarbons from damaged soil. Our research is attempting to identify plant-and-microorganism combinations that can be introduced to contaminated or saline soils in an effort to restore soil health. To this end, botanical surveys were conducted on contaminated land sites throughout Western Canada and plants with a natural propensity to grow in contaminated soils were identified and screened. This work has established our group as a leading authority on phytoremediation technology in Western Canada. Researchers from the department have worked closely with a variety of funding partners including federal government agencies, the Canadian Association of Petroleum Producers (CAPPP) and the United States Environmental Protection Agency to identify plants and soil amendment techniques that facilitate vegetative growth in contaminated soils and remove offending pollutants from the environment.