摘要：

The effects of summer soil solarization on the production and economics of four lettuce cultivars were evaluated in two plantings conducted during the fall growing season of 2001, to determine the feasibility of integrating strip-solarization in plasticulture cropping systems. Soil was solarized for 53 and 34 days for the first and second plantings, respectively, using transparent (T3, T4) and black (T5) films that were kept in place as plastic mulches in raised beds through the fall season. Mulch on T4 was painted black before planting the crop using diluted oil-based paint. Non-solarization treatments included bare-ground (T1) and black plastic mulch installed in the fall (T2). Soil temperatures were recorded at 5 and 10 cm depths at 1 h intervals during the solarization period. Temperature regimes below clear and black plastic mulches were equivalent, although clear film consistently showed longer periods of sustained high temperatures. Solarization with clear and black mulches equally increased lettuce yield by enhancing plant growth and head weight, as plant stand was uniform for all the treatments. Solarization reduced weed densities, especially from grasses. Enhanced weed suppression was achieved by using black plastic for solarization and mulching. Cost analysis indicated that yield increases required to cover solarization expenses in bare-ground and fall-mulch systems are generally lower than yield increases reported in previous solarization research.

展开