Figure 1. Trial layout prior to seedling planting, October 2017.

Sandy Sites – How an exploration of soil amendments lead to lessons about wind erosion.

In fall 2016, Reclaimit president Andrew Carpenter attended ECHO, a tropical agriculture workshop in Florida, where he saw the effects of adding biochar to what was essentially beach sand. The biochar vastly improved the fertility of the sand and allowed the treated area to be used for a highly productive garden. Biochar is created when various feedstocks (wood, agricultural waste, etc.) undergo pyrolysis, or heating in a low oxygen environment. This process creates an extremely porous material that sorbs nutrients, holds water, provides a perfect home for soil microbes and has been shown to permanently improve soil productivity in some conditions. Refer to Eco Community Articles for more information.

Andrew immediately became interested in the potential for this soil additive to improve the reclamation status of large, severely disturbed, sandy sites, such as those that we see at a historical oil sands site Reclaimit is helping to reclaim in northwestern Saskatchewan. Accordingly, Andrew asked Reclaimit ecologist Deanna Van Muyen to devise a trial to field test the effects of biochar amendment on jack pine growth, in addition to a few other treatments. We began installing the trial in the spring of 2017, completing the applications and planting jack pine seedlings in the fall of 2017.

As well as the biochar, we tested both established and novel soil and planting treatments including wood shavings, green manure, peat moss and fertilizer. Altogether, 1000 jack pine seedlings were planted with various amendments in October 2017.

Figure 1. Trial layout prior to seedling planting, October 2017.

Figure 1. Trial layout prior to seedling planting, October 2017.

Results

Unfortunately, a monitoring visit conducted in spring of 2018 revealed that the planted jack pine seedlings had been severely affected by wind erosion and there was apparent widespread mortality. In October 2019 Reclaimit was able to return to the site to collect trial data.

Figure 2. Dead seedlings observed, May 2018.

Figure 2. Dead seedlings observed, May 2018.

Due to high seedling mortality (60%), it was difficult to see definitive patterns in growth response of the jack pine seedlings with respect to the different treatments but we gained some good takeaways about what apparently helped the seedlings survive in these harsh conditions. The simplest solutions, such as the application of peat moss, appeared to work best while those that required surface soil disturbance (biochar, green manure) seemed to exacerbate wind erosion and, consequently, mortality. Further, we found that the plots with more initial natural regeneration had a much better survival than those without. This last point was an anecdotal observation but, along with the other observed results, contributed to a re-evaluation of our prescribed silviculture methods for windswept, sandy sites.

Our investigation of reclamation approaches for sandy sites continues. Watch for updates in future posts!