Davey Tree Flipbooks

11 July/August 2024 | THE DAVEY BULLETIN SOIL RESEARCH OFFERS UNIQUE OPPORTUNITY TO HELP TREES Trees, shrubs and turf growing in the often compacted and nutrient-deprived subsoils of densely developed urban areas face challenges to thrive unlike plants in the natural landscape. A new research study being developed at the Davey SEED (Science, Employee Education and Development) Campus is designed to understand those challenges and develop methods to help those urban plants thrive. "Our industry has a need for long-term simulations of urban conditions where topsoil is removed from sites which are then graded and compacted before being developed. Installing landscaping, the trees, shrubs, turf and other plants, on these sites is often a construction afterthought, leading to frequent plant failure. We will study a variety of soil treatments to learn and demonstrate what works on these types of sites," said Chris Fields-Johnson, tree conservation specialist and technical advisor, Davey Institute. Eight research plots have been designated at the SEED Campus, each of which is 10,000 square feet in size. Four plots will remain as they are with the rich topsoil of a prime agricultural land, and four plots will be stripped of their topsoil which will be replaced by subsoil and compacted by heavy construction equipment to create conditions similar to soil commonly found in an urban development setting. Then, many trees of a variety of species will be planted per plot, and various methods currently used by Davey employees will be studied such as fertilization with Arbor Green PRO ® , incorporation of amendments such as biochar, soil tillage with air tools, and other plant health care (PHC) methods. Fields-Johnson said the goal of the study, which will be conducted by the Davey Institute, is to develop research over the lifespan of those trees – several decades – yielding valuable results to help discover new methods and fine-tune current Davey treatment methods in the first few years. "The goal is to develop comprehensive soil services for our clients which are scientifically defensible with clearly demonstrated results. We want to know that if you prescribe these treatments under these soil conditions, then your plants will have fewer issues, faster establishment, better growth, and better overall health," he said. "This research will apply for any of our clients with urban land and trees where we would be potentially performing PHC treatments, but will also apply to establishing trees on compacted subsoils in general, such as with reforestation of agricultural lands or reclaimed mined lands and brownfields." Above: New research plots at the SEED Campus will study growing conditions for trees, turf and shrubs in compacted subsoil. Many trees of different species will be planted on each of eight plots, half of which will be native topsoil and half of which will be compacted subsoil. Below: New research plots are being prepared at the SEED Campus. VISION

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