At Arborpolitan, our Plant Health Care crew regularly visit gardens to apply fertilizers and soil amendments, unfortunately, we rarely get to closely observe the effects of the products we use.
Out of curiosity, our crew members, LaShaun and Sonia, decided to conduct an experiment on 8 swamp oak saplings found in a Gowanus street tree pit. Four trees were left alone as a control group, while the other four each received a different type of soil amendment/fertilizer every month. All trees were watered once a week depending on the weather. Our hypothesis is: Saplings receiving soil amendments/fertilizer will have faster growth compared to the control group.
Soil amendment/fertilizer used in experiment:
- Endo-Ecto Mycorrhizae with Biostimulants
- A blend of fungus, beneficial bacteria, soluble humate, soluble seaweed, soluble yucca, and vitamins. It contains endo and ecto mycorrhizae. Endomycorrhizal fungi attaches to roots of most plants while ectomycorrhizal fungi form outside of roots of mainly woody plants. Both mycorrhizae help plants to efficiently absorb nutrients, water and even allow plants to be more tolerable of harsh soil conditions.
- Compost from crew office compost bin
- Influence and LC 5-0-3 Liquid Nitrate of Soda/Potassium Sulfate Fertilizer (Nitrate)
- Influence is a biological plant supplement that consists of humic acids, seaweed extract, yucca extract, natural stress reducing hormones, beneficial microorganisms and organic fertility supplements. Nitrate is a liquid fertilizer
- Finesse GVH Granulated Biological Soil Restoration (Granular)
- A soil supplement meant to imitate the biological activity of a forest floor. It consists of composts, organic carbon sources, polysaccharides, hydroxycarboxylic acids, and soluble humate extract. Organic carbon sources act as the annual fall leaves that return carbon to the soil. Polysaccharides are derived from the process of twigs and other cellulose matter breaking down in soils, which aids the development of beneficial fungal organisms.
Oak tree saplings showing signs of stress on June 20th, 2018
Oak Tree Saplings on July 31st, 2018
Oak Tree Saplings on August 28th, 2018
After three months, it seems like saplings, Paul and Simon are showing the most obvious signs of growth. We are curious as to why Sonia and Walker have smaller leaves compared to all of the saplings and why the leaves are turning yellow for Paul and LaShaun. The experiment will end after 9 more months and then the trees will be given away to anyone who wants a new tree. For now, we will be sure to post any updates of the experiment!