Building For The Future: Construction of Soil for Land Reclamation

Valerie S. Miller, Ph.D. Candidate, University of Alberta vsmiller@ualberta.ca

V.S. Miller was also a 2017 3MT participant. Watch the presentation here.

Keywords: land reclamation, soil building, environment, disturbances

We do not inherit the Earth from our ancestors, we borrow it from our children. As a land reclamation scientist, this proverb summarizes the 'why' of my life’s work. Land reclamation is the process of converting disturbed land to its previous or an alternative productive state. It is essentially healing the land after it has been damaged by humans and natural disasters. Globally, approximately 50% of the land has been disturbed by human activities such as mining or poor agricultural practices [1], which reduces environmental health and increases the need for land reclamation (Figure 1).

My research focuses on building soils for reclamation. These soils can be tailored to
address site specific limitations at environmentally disturbed locations worldwide [such as 2]. Suitable soils are essential for successful plant growth and are the foundation of ecosystem development; however, finding a source of soil is a major reclamation challenge. Common sources include soil removed prior to a disturbance or soil taken from another area. Often there is not enough soil [3], additional disturbances are created to get soil, and transportation costs are high [4]. Moving beyond these sources, my research builds soil using onsite mining waste materials, like rock and sewage. Waste becomes part of the solution, providing a low-cost material for soil building [4]. The bonus is that it eliminates the need for management of waste or disposal in
overcrowded landfills.

  Figure 1: Development of land reclamation strategies to heal large scale disturbances.

Figure 1: Development of land reclamation strategies to heal large scale disturbances.

To investigate the soil building process, I conducted greenhouse and small-scale field
experiments at a diamond mine in northern Canada. Mining in the Canadian north has increased dramatically in the last three decades since diamonds were discovered there, requiring development of reclamation strategies that are suitable for remote sites. I tested what materials were effective to build soil, how much of each to use, and how to place these materials to mimic the surface variation of natural environments to successfully support plants. The large number of materials and placement methods tested in my experiments allow soil building strategies to be developed for many different environments with different conditions as the research is not limited to finding a sole solution for a single site. Key results include the improvement of soil by adding organic matter, like sewage and peat, allowing more plants to emerge and grow. Building surface variation, like small ridges and trenches, benefited plants by creating suitable growing sites with added water accumulation and wind protection.

As our population continues to grow and with it our need for resources like fuel and
food, governments, industry, and communities increasingly look to land reclamation for
solutions. Results from my research have developed reclamation strategies that can be
adapted and scaled for use at disturbed sites around the world. As we develop more
successful and innovative methods to heal our damaged world, we become more likely
to return an Earth to our children that is healthy and sustainable.

References

1) Vitousek PM, Mooney HA, Lubchenco J, Melillo JM. Human domination of Earth’s
ecosystems. Science. 1997;277:494-499. DOI: 10.1126/science.277.5325.494

2) Drozdowski BL, Naeth MA, Wilkinson SR. Evaluation of substrate and amendment
materials for soil reclamation at a diamond mine in the Northwest Territories,
Canada. Can J Soil Sci. 2012;92:77-88. https://doi.org/10.4141/cjss2011-029

3) Sheoran V, Sheoran AS, Poonia P. Soil reclamation of abandoned mine land by
revegetation: a review. Int J Soil, Sediment, Water. 2010;3:20 pp.

4) Larney FJ, Angers DA. The role of organic amendments in soil reclamation: a review.
Can J Soil Sci. 2012;92:19-38. https://doi.org/10.4141/cjss2010-064