Dissertation
BIODEGRADABLE PLASTIC MULCH: DEGRADATION AND IMPACTS ON SOIL HEALTH
Doctor of Philosophy (PhD), Washington State University
01/2018
Handle:
https://hdl.handle.net/2376/111629
Abstract
Biodegradable plastic mulch is a potential alternative to polyethylene mulch, but sustainable application will depend on its degradation and impact on soil health. This study evaluated the degradation of four biodegradable plastic mulches in compost and in soil at two sites (Knoxville, TN and Mount Vernon, WA). In addition, the impact of the biodegradable plastic mulches on soil health from continuous application was assessed under pie pumpkin (Cucurbita pepo) production. Cellulosic-paper, polyethylene, and no-mulch served as controls. The biodegradable plastic mulches degraded well in compost, but to a lesser degree in soil. Degradation of the biodegradable plastic mulches in soil after 24 months was <50% in Knoxville and <25% in Mount Vernon. As expected, polyethylene did not degrade, while paper mulch degraded well in both compost and soil. Greater extent of degradation of the biodegradable plastic mulches in Knoxville than in Mount Vernon was primarily due to higher temperature conditions at the former, which also elevated chemical reactions and microbial activities. While polymers of the biodegradable plastic mulches degraded well in compost, micro- and nanoparticles were released, which were a conglomerate of carbon-rich materials containing carbon black. The soil properties used as indicators of soil health were affected more by site, time, and their interactions than by the main effects of mulch type or interactions involving mulch. Generally, the effects of biodegradable plastic mulch on soil health were not cumulative over time because of other disturbances, such as tillage and rainfall, which reset many of the soil properties. The overall effects of mulching on soil health were similar to the no-mulch control. Thus, biodegradable plastic mulch is a promising alternative to polyethylene in agricultural systems, but longer field testing is needed to ensure that either complete degradation occurs or that no long-term harm is caused.
Metrics
18 File views/ downloads
76 Record Views
Details
- Title
- BIODEGRADABLE PLASTIC MULCH: DEGRADATION AND IMPACTS ON SOIL HEALTH
- Creators
- Henry Yabbey Sintim
- Contributors
- Markus Flury (Advisor)Carol A Miles (Committee Member)John P Reganold (Committee Member)
- Awarding Institution
- Washington State University
- Academic Unit
- Department of Crop and Soil Sciences
- Theses and Dissertations
- Doctor of Philosophy (PhD), Washington State University
- Number of pages
- 200
- Identifiers
- 99900581511601842
- Language
- English
- Resource Type
- Dissertation