Cyperus rotundus control by solarization

Soil solarization by means of polyethylene cover sheets was tested for the control of Cyperus rotundus weed infestation. Following solarization, which lasted for a period of approximately three months, the field was cultivate d with carrots and dwarf green beans. Solarization was shown to provide a h ighly significant reduction of the weed population and to increase carrot y ield. As for green beans, soil treatment was less effective and yield was n ot affected. In the solarized plots no weeding was needed during the vegeta ble crops cycle whereas the untreated plots required hand weeding within th e first month from sowing. Soil solarization significantly reduced ant and earthworm numbers but had no effect on millipede population. Soil microbial biomass carbon (SMBC) was affected by solarization. However, actinomycete and bacterial populations, including nitrogen-fixing bacteria, showed no ob vious pattern related to soil solarization.