Soil Quality, Moisture, and Temperature Evaluation Under Different Biodegradable Mulches.

Application of conventional polyethylene mulch (PE) in crop production offers benefits of increased water use efficiency, weed control, management of certain plant diseases, and maintenance of a micro-climate conducive for plant growth. These factors improve crop yield and quality. Nonetheless, producers need to retrieve and safely dispose PE after usage, which increases the total production cost. Substituting PE with biodegradable plastic mulches (BDM) would alleviate disposal needs. However, knowledge of potential impacts of BDMs on agricultural soil ecosystems is needed before successful adoption. We (a) monitored moisture and temperature dynamics, and (b) assessed soil quality upon usage of different mulches, with pie pumpkin (Cucurbita pepo) as the test crop. Experimental field trials are ongoing at two sites, one at Northwestern Washington Research and Extension Center, Mount Vernon, WA, and the other at East Tennessee Research and Education Center, Knoxville, TN. The treatments constitute four different commercial BDM products, one experimental BDM; no mulch and PE served as the controls. Soil quality parameters being examined include those specified in the USDA Soil Quality Test Kit. In addition, soil moisture and temperature sensors, and lysimeters were installed to examine the soil water and heat flow dynamics. Results from the study will be useful for management practices by providing knowledge on how different mulches impact soil quality, temperature, and moisture retention. We present baseline and the first field season results from this study.