Agriculture is a prominent land use on First Nations reserve lands in the Canadian Prairies. Since the 1990s, reserve lands have increased through Specific Claims and Treaty Land Entitlement purchases—as a result of these purchases, total agricultural land holdings are estimated to be as high as 4 million acres in Saskatchewan alone. In spite of the increase in agricultural lands, there are fewer First Nations producers that manage this land and a high proportion of marginal lands on reserve. Indeed, the vast majority of agricultural lands are leased to non-Indigenous producers. First Nations have expressed concerns about degraded soil quality on land leased to non-Indigenous farmers that could reduce land productivity and undermine cultural ties to the land. Confronting land and soil management concerns with lessee farmers requires knowledge of soil fertility, nutrient management, and soil quality and health, among other agriculture management considerations (e.g., pest and weed control). However, Indigenous people are sorely underrepresented in soil science education programs, representing barriers to sustainable soil management. At the same time many First Nations are looking towards restoration of marginal agricultural lands to grasslands as a means to rematriate buffalo and to support other cultural and food sovereignty initiatives. In this context, there are efforts to revitilize and apply Indigenous knowledge of grassland and aspen parkland ecosystems to First Nations land management. Using examples from on-going community-based research and teaching activities, I will highlight the historical and contempory contexts of First Nations agricultural land management, identify the unique challenges and opportunities faced by First Nations, and argue for the need to apply both western soil science and Indigenous knowledge in meeting goals for land and soil management.
Agricultural soil is a non-renewable natural resource that requires careful stewardship in order to achieve the United Nations’ Sustainable Development Goals. However, industrial and agricultural activity is often detrimental to soil health and can distribute heavy metal(loid)s into the soil environment, with harmful effects on human and ecosystem health. In this presentation, I will examine processes that can lead to the contamination of agricultural land with heavy metal(loid)s, which range from mine tailings runoff entering local irrigation channels to the atmospheric deposition of incinerator and coal-fired power-plant emissions. I will discuss the relationship between heavy metal(loid) biogeochemical transformations in the soil and their bioavailability. I will then review two biological solutions for remediation of contaminated agricultural land, plant-based remediation and microbial bioremediation, which offer cost-effective and sustainable alternatives to traditional physical or chemical remediation technologies. Finally, I will discuss how integrating these innovative technologies with profitable and sustainable land use could lead to green and sustainable remediation strategies, and conclude by identifying research challenges and future directions for the biological remediation of agricultural soils.
Every trace element (TE) in the environment has a natural source, in addition to possible contributions from human activities. To quantify anthropogenic contributions of TEs to the environment, natural inputs must be known. Metals such as Pb and metalloids such as Sb have been used commercially for thousands of years. Thus, to identify “background” rates of atmospheric deposition of TEs, we may need to go back in time to the middle of the Holocene to estimate natural inputs to terrestrial ecosystems. Here, soil can help: peat bogs, a unique type of organic soil, serve as environmental archives to enable detailed reconstructions of contemporary and past atmospheric deposition. These types of reconstructions have shown that the dominant natural source of many TEs in the air is soil, in the form of dusts supplied by wind erosion. Similarly, to understand the impacts of human activities on water quality, whether soil solutions, surface waters, or groundwaters, the natural abundance of TEs in pristine waters must be known. For most TEs in surface waters, the dominant source by far is soil. Finally, when we begin to study TEs in plants from remote locations, we find that the dominant natural sources are soil, supplied via root uptake (both essential and non-essential TEs), as well as atmospheric deposition of soil-derived dusts.
Whether TEs are derived from natural or anthropogenic sources, the key to understanding their ecological significance is their bioavailability; this, in turn, requires distinction between particulate, colloidal, and truly dissolved (ionic) chemical species. At the interface between air, water, and biota, soils represent the medium of transformation where TEs may become more or less bioavailable, depending on the chemical behaviour of the element, the physical properties of the host mineral (or amorphous phase), and the composition of the water. Here, some examples are presented which illustrate recent advances in understanding how soil and the particles derived from them, play an inordinate role in TE transformations at the air-water-plant interface, while identifying future research needs and opportunities.
This presentation is dedicated to the Bocock family, with thanks and appreciation for their supreme generosity, on the occasion of the 10th anniversary of the Bocock Chair for Agriculture and the Environment.
A range of ecosystem types – from peatlands to black spruce forests – serve as long term sinks of atmospheric carbon because they accumulate thick peat layers. In turn, peat characteristics influence vegetation, nutrient cycling, and hydrology and also serve at the heart of ecosystem resilience to disturbances such as drought and wildfire. Peat represents a material legacy, in which the historical imbalance between plant productivity and decomposition over long periods of time influences contemporary ecosystem function. We cannot make predictions about the future of Boreal and Arctic ecosystems under a rapidly climate without understanding the future of peat. This presentation will highlight peat as a key northern ecological legacy. I will describe how peat confers ecosystem resilience to changing hydrology and wildfire, and the likely consequences if these peat-dependent resilience mechanisms are overwhelmed. Peat-rich regions of the north are critical for a variety of ecosystem services including access to freshwater, stable infrastructure, and reliable food sources. The drainage of temperate and tropical peatlands for agriculture and timber harvest could be described as one of the world’s largest ecological and climate disasters. To ensure that we do not repeat the mistakes of the past, we desperately need northern-specific conservation plans and best practices that are community-driven and value the important role that peat and peatlands play in ecosystem, landscape, and climate resilience.