Two field experiments were conducted at the Experimental Farm of Horticultural Research Institute (Qaha Farm) during the two successive winter seasons of 2005 and 2006 to elucidate the effect of some soil amendments application such as farmyard manure at 20m3/fed, in addition gypsum at 2 ton/fed, sulphur at 500 kg/fed and their combination besides to the check treatment on vegetative growth, heavy metal uptake (lead and cadmium) by edible parts of lettuce plants (Lactuca sativa L) "cv dark green" and radish (Raphanus sativus L.) "cv white radish" which grown near the Cairo – Alexandria Agriculture road. Traffic densities on the examined road were about 120960 vehicles/day.
The obtained results show that applying farmyard manure, gypsum and/or sulphur reflected the highest values of vegetative growth parameters expressed as fresh and dry weight per plant as well as number of leaves /plant with high significant differences compared with the control treatment (without application). Using soil amendments especially in a mixture form exhibited the highest values of vegetative growth aspects and total yield as well as ascorbic acid content. Heavy metal uptake by edible parts were depressed with the addition of single or mixer application of farmyard manure and gypsum compared with sulphur treatment and the control.
Generally, farmyard manure and gypsum in a single or mixer application gave the best results and are recommended for increasing productivity and improving the quality of lettuce and radish grown near the high densities traffic roads by reduction the heavy metal contents