Removal and disposal of polyethylene mulch in vegetable production represents a high economic and environmental cost to society. This study was conducted in 2006 and 2007 at Michigan State University to test the field performance of new biodegradable mulches using ‘Mountain Fresh Plus’ tomato (Solanum lycopersicum) as a model crop. Treatments included two biodegradable mulches (black and white), each with two thicknesses (35 and 25 μm). A conventional low-density polyethylene (LDPE) mulch of 25 μm was included as a control (a mulch commonly used by vegetable growers). Data loggers were installed 2 cm into the soil under the various mulches to record soil temperature. The experiment used a randomized complete block design with four replications. The mulches were used on a raised bed, drip irrigation system. Mulch degradation, soil temperature, tomato growth, weed density, and biomass were assessed during the seasons. Tomatoes were harvested at maturity and were fruit graded according to market specifications. Results indicate that soil temperature under the biodegradable mulches was greater than that under the LPDE mulch during the first week. Starting the second week, soil temperature dropped gradually under all the biodegradable mulches. The drop in temperature was greatest with the white mulch. Due to premature breakdown of the white mulches, weed pressure was high, resulting in smaller plants with low yield in 2007. Tomato growth, yield, and fruit quality from the black mulch was equivalent to that in the LDPE mulch. Future studies will optimize biodegradability of the mulches and test mechanical laying of the black mulch under commercial production.
Containers made from natural fiber and recycled plastic are marketed as sustainable substitutes for traditional plastic containers in the nursery industry. However, growers’ acceptance of alternative containers is limited by the lack of information on how alternative containers impact plant growth and water use (WU). We conducted experiments in Michigan, Kentucky, Tennessee, Mississippi, and Texas to test plant growth and WU in five different alternative containers under nursery condition. In 2011, ‘Roemertwo’ wintercreeper (Euonymus fortunei) were planted in three types of #1 (≈1 gal) containers 1) black plastic (plastic), 2) wood pulp (WP), and 3) recycled paper (KF). In 2012, ‘Green Velvet’ boxwood (Buxus sempervirens × B. microphylla siebold var. koreana) was evaluated in 1) plastic, 2) WP, 3) fabric (FB), and 4) keratin (KT). In 2013, ‘Dark Knight’ bluebeard (Caryopteris ×clandonensis) was evaluated in 1) plastic, 2) WP, and 3) coir fiber (Coir). Plants grown in alternative containers generally had similar plant growth as plastic containers. ‘Roemertwo’ wintercreeper had high mortality while overwintering in alternative containers with no irrigation. Results from different states generally show plants grown in fiber containers such as WP, FB, and Coir used more water than those in plastic containers. Water use efficiency of plants grown in alternative containers vs. plastic containers depended on plant variety, container type, and climate.