Life Cycle Analysis

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Updated: January 20, 2023

Assessing the Extent of Soil Loss from Nursery Tree Root Ball Excavation (EB-442)

A soil quality management issue unique to tree nurseries is the removal of soil off site with sale of the ornamental trees and shrubs, which are harvested with a balled and burlapped (B & B) root ball. The amount of soil removed with B & B harvest and sale has been estimated as much as 5 cm per year. One piece of evidence that has been used to estimate soil loss during B & B tree harvest is the volume of the holes left behind. However, the soil balls wrapped for B & B removal are generally densely permeated with tree roots, leading some to assume that much or most of the ball removed consist of roots rather than soil. There is a dearth of published data on this soil removal or published methods that will allow for reliable calculation of soil being removed from individual enterprises.The main conclusion from this study is that a balled and burlapped (B & B) root ball consists almost entirely (99%) of soil and that the tree roots take up only a negligible portion of the mass and volume. Our results show that in fact the volume of the hole left behind is a reasonable estimate of the volume of soil removed. Authors: Ray Weil, Margaret Guthrie, Chuck Schuster, and Stanton Gill; Title: Assessing the Extent of Soil Loss from Nursery Tree Root Ball Excavation (EB-442)
Updated: January 5, 2021

Anaerobic Digestion: Basic Processes for Biogas

Anaerobic digestion is a process in which anaerobic bacteria break down or "digest" organic material in the absence of oxygen to produce "biogas" as a byproduct of their metabolism. The process occurs naturally in water-logged soils, deep water bodies, and in the digestive systems of termites and large animals (that includes you). In anaerobic digesters, naturally-occurring biological processes are exploited in an engineered system to treat and dispose of waste materials, stabilize end products, destroy pathogens, and generate biogas, a valuable product. Biogas produced in anaerobic digesters consists of methane (50%– 80%), carbon dioxide (20%–50%), and trace levels of other gases such as hydrogen, carbon monoxide, nitrogen, water vapor, and hydrogen sulfide.