Effect of soil solarization on weed seed bank and soil properties

Soil solarization is a simple, safe, and effective method which controls soil born pests and seeds of many conventional noxious weeds. An experiment was conducted to evaluate the effect of soil solarization on weed seed bank in Mashhad, Iran during summer 2007. A factorial experiment based on randomized complete block design with two factors, solarization with Clear and black polyethylene sheets and non-solarized control, and identified species in seed bank, with three replications was used. In order to study effects of soil organic matter, water content and pH on weed seed bank, soil sample were taken and analysed in all plots. Eleven weed species was identified by studying weed seed bank which were mainly annual broad-leaves species. Results indicated that soil solarization with clear polyethylene sheets reduced weed seed bank significantly, but there was no difference between control and black polyethylene sheets. Soil water content was significantly higher in soil covered with polyethylene sheets, but soil pH and total organic matter remained unchanged. There was a significant negative correlation between weed seed density and water content.