Herbicides persistence in the soil are different depending on the organic matter, moisture, pH, temperature and type of herbicide. Herbicides residuals in the soil may damage next crop in rotation, penetrate to underground water and have some other environmental hazards. Six common herbicide are consisted of Apyrus, Total, Topic, U46, Atlantis, Axial and Othello and three new herbicides as well as Perun, Attribute super and Lancelot applied in recommended doses with check. Soil sampling (2 kg) was done three times; 120, 150 and 180 days after herbicides application, and then after wheat harvest, transported to the pots. Test plants; garden cress (Lepidium sativum); tomato, cucumbers and corn planted in pots containing soil samples. To prevent herbicides leaching from the soil, pots were irrigated with underground irrigation system (from the bottom of pot). Plants harvested and the biomass measured 30 days after emergence, and germination percentage and growth rate recorded. The result showed that all herbicides had a negative effect on the test plants. Othello and Total had the highest impact on biomass reduction (by 90%), growth rate and germination percentage compared to the control pot. Furthermore, the effect of time of sampling on traits was so significant that soil sample from the 180 days after herbicide application had the highest biomass, growth rate and percent of germination compared to the other time of sampling. The interaction of time and herbicide was significant for biomass in all the test plants. One result of this study suggested that the new herbicide had residual less than the other common herbicide. 1st International and 5th National Conference on Organic vs. Conventional Agriculture
