Researchers at New Mexico State University are evaluating the use of plastic beverage bottles as an alternative nursery seedling container where it is not cost-effective to import containers used in industrialized-nation nurseries.
“Discarded plastic bottles are a potential resource as growing containers for nurseries in developing countries,” said Owen Burney, NMSU assistant professor and superintendent of the John T. Harrington Forestry Research Center in Mora. “These bottles ordinarily have a very short lifespan, usually lasting only for the duration of consumption of the beverage. Where recycling and waste management are limited, such as in many developing countries, these containers end up in streets, waterways and open areas.”
Burney was a part of a Purdue University project, Strengthening Afghan Agricultural Faculty, sponsored by the U.S. Agency for International Development based in Kabul, Afghanistan. With the aid of Afghan forestry professors, Burney started a greenhouse nursery for Kabul University using discarded plastic bottles as the containers to grow forest seedlings.
When USAID funding for the project decreased the project was reorganized, ending Purdue University’s stay in Afghanistan. However, it held onto the most critical component, funding 13 Afghan agriculture faculty members to obtain their master’s and doctoral degrees at three U.S. universities — Purdue, North Carolina State and Washington State.
One of the Purdue graduate students – Safiullah Khurram – is working with Burney at NMSU’s facility in Mora to evaluate the plastic beverage bottles. Khurram spent three weeks in New Mexico this summer establishing two experiments.
One experiment is examining the influence of root spiral control methods and bottle opacity by using clear, green and black bottles while raising Afghan pine seedlings.
“One problem with smooth-sided containers is that the plant’s roots spiral once they touch the side,” Khurram said. “In the nursery containers used here in the U.S., there is a slight raised line that causes the root to stop spiraling and turn downward.”
Planting seedlings with spiraled roots can significantly impede growth and survival. Proper root architecture is critical for planting success.
The second experiment compares hardwood and conifer species grown in different types of containers that include plastic bottles, containers used in operational nurseries here in the U.S., and polybags, small plastic bags used in developing countries.
“The overall research is focused on the developmental biology of seedlings, both hardwoods and conifers, grown in a variety of container types in which comparisons will be made in part by measuring root structure, overall growth and survival,” Burney said.
Results from this study will help to determine the effectiveness of plastic bottles for nurseries growing seedlings and other native plants for reforestation, conservation, agroforestry and restoration not only in developing countries but anywhere around the world.
“Discarded plastic beverage bottles are a major problem around the world,” Burney said. “If this study proves successful, it is positive step in reducing the impacts of plastic bottles on the environment not only in developing countries, but industrialized nations as well.”