Does soil solarization kill beneficial soil organisms?
Populations of some beneficial organisms, such as Trichoderma spp. or actinomycetes, may be increased by solarization. Other important soilborne organisms, such as mycorrhizal fungi, may be decreased in the upper soil profile but not enough to lessen their beneficial action. Populations of some microorganisms, such as beneficial bacteria (Bacillus and Pseudomonas spp.) are partially decreased during solarization but afterwards recolonize the soil rapidly. However, populations of Rhizobium spp. of bacteria, which fix nitrogen in root nodules, are killed and must be reintroduced with seeds of legume crops. Survival and activation of beneficial organisms appear to play an important role in the increased plant growth commonly observed in solarized soils. Can soil solarization be used in cooler areas such as those near the coast? Soil solarization may be partially effective in cooler coastal areas if treatment occurs during periods of highest air temperatures and when skies are clear. Howev
