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Effects of soil booster product on sawmill reclamation site

in Narrow Hills Provincial Park

Thuan Chu, Senior Park Landscape Ecologist, Landscape Protection Unit

Pat Mackasey, Park Forest Ecologist, Landscape Protection Unit

Ministry of Parks, Culture and Sport

Abstract

Postindustrial activities in Saskatchewan park lands require both soil reclamation and ecological

restoration to maintain the integrity of park ecosystem and landscape. A sawmill in Narrow Hills Provincial

Park has been abandoned in the middle 2000s and left behind multiple large piles of sawdust. The

abandoned site has been reclaimed by spreading sawdust over the area and then planted with

containerized white spruce seedlings in the spring 2019. This study evaluates the effects of using a soil

booster product that was mined from the soil without farming for long time (> 100 years) as a soil

amendment for the reclaimed site. Initial results showed that adding the soil booster product with the

rate of 80 lb/acre can facilitate the growth of seedling and reduce mortality rate after the first growing

season. Further assessment in following growing seasons is necessary to confirm the significant effects of

the product on changes in soil nutrients and plant growth productivity. Findings of this study will assist

Parks Division to decide whether the soil booster product should be used for soil reclamation projects in

parks land and at which rate the product should be applied to enhance the growth of native plant and

increase soil nutrients. This will also contribute to the success of the silviculture program in many parks

by Parks Division – Landscape Protection Unit.

1. Introduction

During the middle 1970s to the middle 2000s, Narrow Hills Provincial Park was home to a sawmill near

the Upper Fishing Lakes area. It operated full time and was an important local employer. When the mill

was abandoned, it left a 13 hectares clearing in the forest and multiple large piles of sawdust (Figure 1).

There was no evidence of tree regeneration on the site, and visible sawdust piles were not decomposing.

Parks Division completed a cumulative effects assessment of NHPP in 2016 to assess the levels of both

anthropogenic and natural disturbances. Unfortunately, following some critical fires in the 1970s and

1980s, widespread salvage forest harvesting took place which left the park forest land riddled with many

roads and trails. Most of this timber harvested was processed at the sawmill, with no control on sawdust

accumulations.

Parks Division has been cooperating with the Ministry of Environment, Fish & Wildlife Branch to minimize

and restore disturbances on park forest land, with the former sawmill site targeted as a candidate area to

reclaim. These objectives strongly align with the Woodland Caribou Recovery Strategy for SK2, which

includes NHPP. A large area of the park’s forest has recently advanced into the 40-50-year age class and

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consists of a large amount of jack pine, resulting in high quality woodland caribou habitat. Saskatchewan

Research Council was contracted to develop a site reclamation prescription which was put for tender in

2018.

Most of the site consists of sandy loam, most of which was missing an L, F, H horizon and seemed to still

be recovering from development and compaction. The areas where sawdust was buried had about a 50-

100 cm clay cap on top and former Top soil was mostly absent and also likely compacted. The site was

formerly occupied by mixedwood aspen/balsam poplar/white spruce forest and the intent is to restore

the site to the initial forest cover type. The site was left to natural processes, which resulting in some low

stocking of trembling aspen and jack pine in various pockets, as well as patches of shrubs such as pin

cherry and green alder. The LPU treated a large area for common tansy in the fall of 2016. In the winter

2018, Parks Division conducted a project to reclaim the site by spreading sawdust to the north and

northwest of the piles (Figure 1). Bucket loader, dump trucks and bull dozer were used. Sawdust was

mixed and incorporated into soil surface with a Rome Plough. The reclamation project was finished in

April, 2019. However, this work completed spreading about 70% of sawdust in the central pile. More

reclamation work needs to be done for the southeast pile.

Following the soil reclamation, Parks Division has planned for planting of balsam poplar (Populus

balsamifera) and white spruce (Picea glauca) on the site in the following years. In May 2019, Grassroots

Organic Dirt Supplements Co. Inc. based in McCord, Saskatchewan offered one tonne of humic substance

(i.e. Soil Booster product), which can be used as a soil amendment to increase soil micro nutrients and soil

biology. The soil booster product has been mined from the soil from over 100 years of farming or, in some

cases farming was never present. The product contains 70 trace minerals and pure programmed Bentonite

clay from Switzerland. This combination stimulates existing soil micro biology and accelerate

decomposition process to make nutrients available to plants. The product has been certified to use for

crop production in Canada by Organic Materials Review Institute (OMRI) in accordance with the Canadian

Organic Standards (Cheesman, 2019).

To ensure the benefits of Soil Booster product and its positive effectiveness on forest land restoration and

boreal tree growth, Parks Division established a field experiment in a Narrow Hills Provincial Park sawmill

reclamation site in May, 2019. The experiment consisted of four treatments with the different rates of

the bio-product application, three bio-product treatments (80 lb/acre, 160 lb/acre, and 320 lb/acre) and

one control treatment (0 lb/acre). Following the product applications, white spruce was planted on the

experiment site at a density of 1600 trees/ha. The effects of bio-product were examined by monitoring

the growth of white spruce seedling root collar diameter and height as well as seedling mortality in the

first four growing seasons (2019-2022). The effects on soil condition and natural regeneration of other

vegetation (e.g. grasses & shrubs) will be evaluated from the second growing season (i.e. 2020). We

hypothesized that the amendment of soil booster product on the reclaimed soil increases total plant

productivity and alters positive soil conditions as compared to having no soil amendment. This will assist

Parks Division to decide whether soil amendment should be used for soil reclamation projects in park land

and at which rate the product should be applied to maximize native plant growth and soil nutrients

availability.

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Figure 1. Location of sawmill reclamation and field experiment site in NHPP

2. Material and Methods

2.1. Experimental field design

Grassroots Organic Dirt Supplement Co. Inc has mined soil booster product from the soil with over 100

years of farming or, in some cases where farming was never present. An analysis conducted by the

company shows that the product contains over 70 trace minerals. Many of these minerals will increase

microbial activity in the soil releasing usable phosphorus and nitrogen to the plants as well as many micro

nutrients. In crop production, it has been recommended that the product can be spread evenly on surface

in fall or early spring. It can also be applied in row at seeding. The recommended application rate for

cropping is 40 lb/arce. As the reclaimed site has high percentage of undecomposed sawdust, we applied

Area where sawdust

was spread and

mixed with topsoil. Experiment site

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the product at higher recommended rate (i.e. 80 lb/acre, 160 lb/acre, 320 lb/acre). These are also

reasonable rates to examine as tree grows slowly and takes up nutrients longer than crops.

The field experiment started in May 2019 and consisted of 4 treatments and 6 replicate blocks, resulting

in 24 plots in total, set up as a randomized complete block design. Each block was 20 m wide and 60 m

long and contained four plots with the different treatments of applying soil booster at the rate of 80

lb/acre, 160 lb/acre, 320 lb/acre, and no soil amendment (0 lb/acre). Each plot measured 15 x 20 m. The

soil booster product was spread evenly on surface using fertilizer spreader attached on UTV. White spruce

was planted at spacing of 2.7 m and avoided planting near the edge of each plot. All measurements were

conducted within the inner 15 x 20 m area of each plot. Figure 2 & 3 shows the experimental design on

the field.

Figure 2. Experimental design for soil booster product application in NHPP sawmill reclaimed site. Number

in each 15 x 20 m plot indicates the application rate of the product (lb/acre).

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Figure 3. LPU staff working on experimental design in May 2019

2.2. Seedling growth measurement

Vegetation assessments were conducted at the end of first growing season in October 2019. All seedlings

in the experiment blocks were measured for root collar diameter, seedling height and mortality. Seedling

height and root collar diameter were measured by steel measuring tape and electric caliper, respectively.

Tree mortality was counted for number of dead and under stressed seedlings in each plot. All data were

recorded in the field data sheet (Appendix 1). The growth of herbaceous plants and shrubs including

invasive species was also observed and briefly described after first growing season. The detail assessment

of these other plants will be conducted in the next growing seasons. Similarly, sampling and assessment

of soil nutrients impacted by the soil amendment will be conducted in the next growing seasons.

2.3. Statistical analyses

Collected data were analyzed using analysis of variance (ANOVA) in R software. For all statistical analyses,

data from multiple plots with the same application rate were averaged before analyses, as they are

pseudoreplicates. This resulted in 24 data points for all analyses of data collected from the field

experiment (four treatments x six replicate blocks). Before conducting ANOVA, data were checked for

homogeneity of variances using Barlett test and for normality by Shapiro test. Most data failed

homogeneity of variance and normal distribution assumptions. Therefore, a Kruskal-Wallis test was used

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as a nonparametric equivalent to one or two-way analysis of variance. Significant differences among pairs

of treatments were then determined with a Mann-Whitney rank sum test. As non-parametric test is

conservative (Dytham 2003), significance was determined at p-value < 0.100 to increase power (Zar 1999).

3. Results

3.1. Seedling mortality

Seedling mortality in this study refers to the death or partial death of white spruce seedlings and provides

a measure of seedling health after the first growing season. The mortality of seedling may be caused by

weather variability (e.g. drought or cold temperature), by insect pests and disease, or by lack of suitable

soil nutrients. Our assessment after the first growing season shows that the survival rates in all

experiments were very high (>90%). The lowest tree mortality (2.5%) was observed in the experimental

plots with the application rate of 80 lb/acre of soil booster product, and the highest seedling mortality

(6.3%) was in the plots without soil booster (Figure 4). Previous studies showed that microsite conditions

(e.g. mineral soil mounds, rotten logs, exposed patches of mineral soil & soil organic horizons LFH)

(DeLong et al. 1997), mechanical site preparation (e.g. v-blade, disc trencher & Bracke mounder)

(Archibold et al. 1999, Macdonald et al. 1998), and type of seedlings (e.g. bare root, container and

improved root system) (Dumins & Lazdina, 2018) could be factors affecting first year survival of spruce

seedlings. As the field experiment in this study was designed on the site with the similar microsite

condition, mechanical site preparation, and type of seedling (i.e. containerized plug styroblock seedling),

the impacts of these factors on the seedling growth could be assumed homogeneity. However, to confirm

whether there is significant effect of the soil amendment on white spruce seedling growth, further

assessment including soil sampling in the following growing seasons are required.

Figure 4. Seedling mortality in the field experimental plots after the first growing season.

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3.2. Seedling growth

Descriptive statistics shows that seedling root collar diameter and height were highest in the plots with

the application rate of 80 lb/acre, 4.52 mm and 22.25 cm respectively (Table 1, Figure 5). The median

values of root collar diameter and height were also highest with the application rate of 80 lb/acre. In other

words, more than 50% of seedlings has equal or higher than 4.42 mm growth in root collar diameter and

22.67 cm in height, respectively, showing increase in total plant productivity with the application rate of

80lb/acre.

Table 1. Summary of seedling growth in different experiments

Root Collar Diameter (mm) Height (cm)

Ex0 Ex80 Ex160 Ex320 Ex0 Ex80 Ex160 Ex320

∑seedling 254 262 250 256 254 262 250 256

Mean 4.22 4.52 4.24 4.35 21.75 22.25 21.83 22.22

Median 4.22 4.42 4.29 4.03 21.42 22.67 21.85 21.65

Min 2 2.2 2 2.1 10 12 12 12

Max 7 8.5 6.8 7.9 33 34.5 33 32

Standard Dev. 0.85 0.98 0.87 0.92 4.56 4.15 4.4 4.11

Standard Err. 0.05 0.06 0.05 0.05 0.28 0.25 0.27 0.25

Figure 5. Box plots of root collar diameter (mm) and seedling height in different experiments.

3.3. Significant effects of soil booster on seedling growth

To examine whether there was a statistically significant difference in seedling growth among experiments,

a non-parametric test (i.e. Kruskal-Wallis & Mann-Whitney rank sum test) was used. Even though the

average of root collar diameter and seedling height was higher in the plots with the application rate of 80

lb/acre, this incremental growth of seedlings was not significantly different from other treatments after

first growing season (p-value > 0.1) (Table 2). Tree seedlings in the experiment site show prolific growth

and performance after first growing season probably due to the high levels of macro nutrients (e.g. N, P,

K) retained in the seedling plugs. Therefore, continuous monitoring of seedling growth in the following

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growing seasons is necessary confirm the effect of soil booster product on soil micro nutrients and

seedling growth.

Table 2. Statistical test for significant difference in seedling growth among treatments

Ex0 Ex80 Ex160 Ex320 Chi-squared p-value

Diameter (mm) 4.22 ± 0.05 4.52 ± 0.06 4.24 ± 0.05 4.35 ± 0.05 2.28 (3) 0.51

Height (cm) 21.75 ± 0.28 22.25 ± 0.25 21.83 ± 0.27 22.22 ± 0.25 0.45 (3) 0.93

4. Conclusion and Recommendation

After fist growing season, there was lower mortality rate and higher growth in root collar diameter and

height of white spruce seedlings in the reclaimed site with the application rate of 80 lb/acre of soil booster

product. Even though this was not statistically significant difference (p-value > 0.05), the results showed

potential positive effects of the product on soil nutrients and plant productivity.

As seedlings can grow within their initial and container-induced characteristics in the first growing season,

the impacts of site conditions, including soil amendment and other environmental factors, on seedling

growth are limited (Pinto et al. 2011). Therefore, continuous observations in the following growing

seasons would provide more data to confirm the effects of soil booster product on the growth of planted

seedlings. We plan to have more assessments at the end of each growing season (2020-2022) as follows:

continue with measurements of root collar diameter, seedling height, and tree mortality;

collect and analyze soil samples for each treatment, including analysis of soil pH, ammonium,

nitrate, phosphorus, potassium, sulfate, total C, total N and C: N ratio;

monitor natural regeneration of other plants within the area, such as native grasses, forbs and

shrubs as well as invasive species.

The remaining 10 ha of the project site will be planted with a mix of balsam poplar and white spruce in

the spring of 2020. Other experiments can be established to evaluate the impacts of soil booster product

on other broadleaf tree species (e.g. trembling aspen & balsam poplar) and/or mixed wood forest in the

reclaimed site.

Acknowledgements

Funding for this research from Landscape Protection Unit, Parks Division, Saskatchewan Ministry of Parks,

Culture and Sport. We would like to have grateful acknowledgement to Grassroot Organic Dirt

Supplements Co. Inc. for providing the soil booster product to conduct the field experiment. The authors

also thank Michel Trembley, former Park Grassland Ecologist for the establishment of field experiment,

Cameron Koslowski and park staff in Narrow Hills Provincial Park for tree planting in the site.

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References

Cheesman, M. 2019. Grassroot organic dirt supplements – Soil booster product. Grassroot Organic Dirt

Supplements Co. Inc. http://www.grosupplements.ca. Accessed May 2019.

Dytham, C. 2003. Choosing and using statistics: a biologist’s guide. 2nd edition. Blackwell Publishing,

Oxford, United Kingdom.

Zar, J. H. 1999. Biostatistical analysis. 4th edition, Prentice Hall, Upper Saddle River, New Jersey.

DeLong, H. B., Lieffers, V. J., & Blenis, P. V. (1997). Microsite effects on first-year establishment and

overwinter survival of white spruce in aspen-dominated boreal mixedwoods. Canadian Journal of Forest

Research, 27(9), 1452-1457.

Archibold, O. W., Acton, C., & Ripley, E. A. (2000). Effect of site preparation on soil properties and

vegetation cover, and the growth and survival of white spruce (Picea glauca) seedlings, in

Saskatchewan. Forest Ecology and Management, 131(1-3), 127-141.

Macdonald, S. E., Schmidt, M. G., & Rothwell, R. L. (1998). Impacts of mechanical site preparation on foliar

nutrients of planted white spruce seedlings on mixed-wood boreal forest sites in Alberta. Forest Ecology

and Management, 110(1-3), 35-48.

Dumins, K., & Lazdina, D. (2018). Forest regeneration quality–factors affecting first year survival of planted

trees. RESEARCH FOR RURAL DEVELOPMENT, 1.