Published 2018-03-15
Abstract
Used potting soil from the environmental horticulture industry is a problematic waste. In conversations with growers, it is estimated that about 10% of plants with potting soil are culled and disposed of in the industry. These culled plants and soil are typically dumped on site and generally not reused. In an effort to recycle this waste, a series of methods were tested to solarize the used potting media. Solarization is a sustainable, inexpensive, and effective method to reduce pathogens, nematodes and weeds. Soil moisture, plastic thickness, bed depth, and covering configurations were manipulated to generate best outcomes. Successful methods were achieved using a small (one cubic yard) and larger scale (3.65 cubic yards) approach. Highest temperatures in the study reached a maximum of 159 °F in the large scale experiment. Solarization reduced nematode populations compared to untreated soil. Weed seed germination at 14 days was reduced about 91% compared to untreated soil.